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Sample records for au au collisions

  1. Charged particle density distributions in Au+ Au collisions at ...

    Indian Academy of Sciences (India)

    ... measured in Au + Au collisions using the BRAHMS detector at RHIC. The results are presented as a function of the collision centrality and the center of mass energy. They are compared to the predictions of different parton scattering models and the important role of hard scattering processes at RHIC energies is discussed ...

  2. Multifragmentation in Au + Au collisions studied with AMD-V

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Akira [Tohoku Univ., Sendai (Japan). Faculty of Science

    1998-07-01

    AMD-V is an optimum model for calculation of multifragmentation in Au + Au collisions. AMD-V consider anti-symmetry of incident nucleus, target nucleus and fragments, furthermore, it treat the quantum effect to exist many channels in the intermediate and final state. 150 and 250 MeV/nucleon incident energy were used in the experiments. The data of multifragment atom in {sup 197}Au + {sup 197}Au collisions was reproduced by AMD-V calculation using Gognny force, corresponding to the imcompressibility of nuclear substance K = 228 MeV and its mean field depend on momentum. When other interaction (SKG 2 force, corresponding to K = 373 KeV) was used an mean field does not depend on momentum, the calculation results could not reproduce the experimental values, because nucleus and deuteron were estimated too large and {alpha}-particle and intermediate fragments estimated too small. (S.Y.)

  3. Global polarization measurement in Au+Au collisions

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev,V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2007-08-02

    The system created in non-central relativisticnucleus-nucleus collisions possesses large orbital angular momentum. Dueto spin-orbit coupling, particles produced in such a system could becomeglobally polarized along the direction of the system angular momentum. Wepresent the results of Lambda and anti-Lambda hyperon global polarizationmeasurements in Au+Au collisions at sqrt sNN=62.4 GeV and 200 GeVperformed with the STAR detector at RHIC. The observed globalpolarization of Lambda and anti-Lambda hyperons in the STAR acceptance isconsistent with zero within the precision of the measurements. Theobtained upper limit, lbar P Lambda, anti-Lambda rbar<= 0.02, iscompared to the theoretical values discussed recently in theliterature.

  4. Chiral magnetic effect search in p+Au, d+Au and Au+Au collisions at RHIC

    Science.gov (United States)

    Zhao, Jie; STAR Collaboration

    2017-09-01

    The chiral magnetic effect (CME) is a fundamental property of QCD. A major background source for CME measurements is the intrinsic particle correlations (such as resonances/jets decay) coupled with the azimuthal elliptical anisotropy v2. In heavy-ion collisions, the magnetic field direction and event plane azimuthal angle Ψ2 are correlated, thus the CME and the v2-induced background are entangled. In small system p+Au and d+Au collisions, the Ψ2 is mostly due to geometry fluctuations, and thus magnetic field direction and Ψ2 are uncorrelated. The correlation measurements in small system collisions with respect to Ψ2 are only sensitive to v2-induced background while any CME is averaged to zero. In this talk, we will present the STAR measurements of two-particle correlations with respect to Ψ2 in p+Au, d+Au and Au+Au collisions at √{sNN} = 200 GeV. These results are analyzed as a function of particle multiplicity to shed light on the background contaminations of the CME measurements in heavy-ion collisions. We will also report results from a new analysis approach as a function of the particle pair invariant mass in order to suppress non-CME related physics backgrounds.

  5. PHENIX Results in d + Au Collisions

    Science.gov (United States)

    Chen, Chin-Hao

    2016-04-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a comprehensive set of measurements in d + Au collisions. Observables in d + Au collisions were originally conceived as a control experiment where no quark-gluon plasma is formed and one could isolate so-called cold nuclear matter effects, including nuclear modified parton distributions and parton multiple scattering. However, recent data from the PHENIX experiment in d + Au, in conjunction with new p + Pb results at the Large Hadron Collider, give strong evidence for a very different picture. We present new results that hint at the formation of a small quark-gluon plasma, that though short lived, leaves a fingerprint of evidence on final state observables. These new results will be discussed in the context of competing theoretical interpretations.

  6. Initial Eccentricity in Deformed 197Au+197Au and 238U+238U Collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Filip, Peter; Lednicky, Richard; Masui, Hiroshi; Xu, Nu

    2010-07-07

    Initial eccentricity and eccentricity fluctuations of the interaction volume created in relativistic collisions of deformed {sup 197}Au and {sup 238}U nuclei are studied using optical and Monte-Carlo (MC) Glauber simulations. It is found that the non-sphericity noticeably influences the average eccentricity in central collisions and eccentricity fluctuations are enhanced due to deformation. Quantitative results are obtained for Au+Au and U+U collisions at energy {radical}s{sub NN} = 200 GeV.

  7. Profiling hot and dense nuclear medium with high transverse momentum hadrons produced in d+Au and Au+Au collisions by the PHENIX experiment at RHIC

    Directory of Open Access Journals (Sweden)

    Sakaguchi Takao

    2014-03-01

    Full Text Available PHENIX measurements of high transverse momentum (pT identified hadrons in d+Au and Au+Au collisions are presented. The nuclear modification factors (RdA and RAA for π0 and ƞ are found to be very consistent in both collision systems, respectively. Using large amount of p + p and Au+Au datasets, the fractional momentum loss (Sloss and the path-length dependent yield of π0 in Au+Au collisions are obtained. The hadron spectra in the most central d+Au and the most peripheral Au+Au collisions are studied. The spectra shapes are found to be similar in both systems, but the yield is suppressed in the most peripheral Au+Au collisions.

  8. Multistep production of eta and hard pi(0) mesons in subthreshold Au-Au collisions

    NARCIS (Netherlands)

    Appenheimer, M; Averbeck, R; Charbonnier, Y; Diaz, J; Doppenschmidt, A; Hejny, [No Value; Hlavac, S; Holzmann, R; Kugler, A; Lohner, H; Marin, A; Metag, [No Value; Novotny, R; Ostendorf, RW; Pleskac, R; Schubert, A; Schutz, Y; Simon, RS; Stratmann, R; Stroher, H; Tlusty, P; Vogt, PH; Wagner, [No Value; Weiss, J; Wilschut, HW; Wissmann, F; Wolf, M

    1998-01-01

    The neutral pi(o) and eta mesons are studied in Au-197-Au-197 collisions at an incident energy of 800A MeV, substantially below the threshold for eta production in N-N collisions. While the gross pi(o) multiplicity increases almost linearly with the number of participant nucleons, the multiplicities

  9. Charged particle density distributions in Au·Au collisions at ...

    Indian Academy of Sciences (India)

    Charged particle pseudorapidity distributions have been measured in Au·Au collisions using the BRAHMS ... Relativistic heavy-ion collisions; charged hadron production; pseudorapidity distribu- tions; centrality .... the predictions of two different theoretical models: (i) the high density gluon saturation model of Kharzeev and ...

  10. PHENIX results on collectivity in high-multiplicity p + Au, d + Au and 3He + Au collisions

    Science.gov (United States)

    Xu, Qiao

    2016-08-01

    We present recent PHENIX results for long-range two-particle correlation functions across a large pseudorapidity(η) gap in high-multiplicity p+Au, d+Au and 3He+Au collisions. Enhanced correlations are observed for particles with small azimuthal separation. Measurements of the second order Fourier coefficients (v 2) in p/d/3He+Au collisions, and the third order Fourier coefficient (v 3) in 3He+Au collision are performed using the event plane method. Scaling of v 2 with the initial eccentricity (ɛ 2) is performed in each system to investigate the role of the initial geometry in the development of a final-state anisotropy in the particle emission. The v 2 coefficients for identified π±, K± and (anti-)proton are measured as a function of transverse kinetic energy (KET) and their magnitudes are found to scale approximately with the number of constituent quarks in the hadron.

  11. Jets and dijets in Au+Au and p+p collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Hardtke, D.; STAR Collaboration

    2002-12-09

    Recent data from RHIC suggest novel nuclear effects in the production of high p{sub T} hadrons. We present results from the STAR detector on high p{sub T} angular correlations in Au+Au and p+p collisions at {radical}S = 200 GeV/c. These two-particle angular correlation measurements verify the presence of a partonic hard scattering and fragmentation component at high p{sub T} in both central and peripheral Au+Au collisions. When triggering on a leading hadron with p{sub T}>4 GeV, we observe a quantitative agreement between the jet cone properties in p+p and all centralities of Au+Au collisions. This quantitative agreement indicates that nearly all hadrons with p{sub T}>4 GeV/c come from jet fragmentation and that jet fragmentation properties are not substantially modified in Au+Au collisions. STAR has also measured the strength of back-to-back high p{sub T} charged hadron correlations, and observes a small suppression of the back-to-back correlation strength in peripheral collisions, and a nearly complete disappearance o f back-to-back correlations in central Au+Au events. These phenomena, together with the observed strong suppression of inclusive yields and large value of elliptic flow at high p{sub T}, are consistent with a model where high p{sub T} hadrons come from partons created near the surface of the collision region, and where partons that originate or propagate towards the center of the collision region are substantially slowed or completely absorbed.

  12. Charged hadron transverse momentum distributions in Au+Au collisions at {radical}S{sub NN} = 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Back, B.B.; Baker, M.D.; Barton, D.S.; Betts, R.R.; Ballintijn, M.; Bickley, A.A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M.P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G.A.; Henderson, C.; Hofman, D.J.; Hollis, R.S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C.M.; Lin, W.T.; Manly, S.; McLeod, D.; Michalowski, J.; Mignerey, A.C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I.C.; Pernegger, H.; Reed, C.; Remsberg, L.P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S.G.; Steinberg, P.; Stephans, G.S.F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G.J. van; Verdier, R.; Wadsworth, B.; Wolfs, F.L.H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A.H.; Wyslouch, B

    2003-04-01

    We present transverse momentum distributions of charged hadrons produced in Au+Au collisions at {radical}S{sub NN} = 200 GeV. The evolution of the spectra for transverse momenta p{sub T} from 0.25 to 5 GeV/C is studied as a function of collision centrality. We find a significant change of the spectral shape between proton-antiproton and peripheral Au+Au collisions. When comparing peripheral to central Au+Au collisions, we find that the yields at the highest p{sub T} exhibit approximate scaling with the number of participating nucleons, rather than scaling with the number of binary collisions.

  13. Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR

    Energy Technology Data Exchange (ETDEWEB)

    STAR Coll

    2009-04-11

    Identified charged particle spectra of {pi}{sup {+-}}, K{sup {+-}}, p and {bar p} at mid-rapidity (|y| < 0.1) measured by the dE/dx method in the STAR-TPC are reported for pp and d + Au collisions at {radical}s{sub NN} = 200 GeV and for Au + Au collisions at 62.4 GeV, 130 GeV, and 200 GeV. Average transverse momenta, total particle production, particle yield ratios, strangeness and baryon production rates are investigated as a function of the collision system and centrality. The transverse momentum spectra are found to be flatter for heavy particles than for light particles in all collision systems; the effect is more prominent for more central collisions. The extracted average transverse momentum of each particle species follows a trend determined by the total charged particle multiplicity density. The Bjorken energy density estimate is at least several GeV/fm{sub 3} for a formation time less than 1 fm/c. A significantly larger net-baryon density and a stronger increase of the net-baryon density with centrality are found in Au + Au collisions at 62.4 GeV than at the two higher energies. Antibaryon production relative to total particle multiplicity is found to be constant over centrality, but increases with the collision energy. Strangeness production relative to total particle multiplicity is similar at the three measured RHIC energies. Relative strangeness production increases quickly with centrality in peripheral Au + Au collisions, to a value about 50% above the pp value, and remains rather constant in more central collisions. Bulk freeze-out properties are extracted from thermal equilibrium model and hydrodynamics-motivated blast-wave model fits to the data. Resonance decays are found to have little effect on the extracted kinetic freeze-out parameters due to the transverse momentum range of our measurements. The extracted chemical freeze-out temperature is constant, independent of collision system or centrality; its value is close to the predicted phase

  14. Directed flow of antiprotons in Au+Au collisions at AGS

    OpenAIRE

    Barrette, J.; Bellwied, R.; Bennett, S.; Bersch, R.; Braun-Munzinger, P.; Chang, W. C.; Cleland, W. E.; Clemen, M.; Cole, J.; Cormier, T. M.; Dai, Y.; David, G.; Dee, J.; Dietzsch, O.; Drigert, M.

    2000-01-01

    Directed flow of antiprotons is studied in Au+Au collisions at a beam momentum of 11.5A GeV/c. It is shown that antiproton directed flow is anti-correlated to proton flow. The measured transverse momentum dependence of the antiproton flow is compared with predictions of the RQMD event generator.

  15. Elliptic flow in Au+Au collisions at $\\sqrt{S_{NN}}$=130 GeV

    CERN Document Server

    Ackermann, K H; Adler, C; Ahammed, Z; Ahmad, S; Allgower, C; Amsbaugh, J; Anderson, M; Anderssen, E; Arnesen, H; Arnold, L; Averichev, G S; Baldwin, A R; Balewski, J T; Barannikova, O Yu; Barnby, L S; Baudot, J; Beddo, M E; Bekele, S; Belaga, V V; Bellwied, R; Bennett, S; Bercovitz, J; Berger, J; Betts, W; Bichsel, H; Bieser, F; Bland, L C; Bloomer, M A; Blyth, C O; Böhm, J; Bonner, B E; Bonnet, D; Bossingham, R R; Botlo, M; Boucham, A; Bouillo, N; Bouvier, S; Bradley, K; Brady, F P; Braithwaite, E S; Braithwaite, W; Brandin, A B; Brown, R L; Brugalette, G; Byrd, C; Caines, H; Calderón de la Barca-Sanchez, M; Cardenas, A; Carr, L; Carroll, J; Castillo, J; Caylor, B; Cebra, D; Chathopadhyay, S; Chen, M L; Chen, W; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Chrin, J; Christie, W; Coffin, J P; Conin, L; Consiglio, C; Cormier, T M; Cramer, J G; Crawford, H J; Danilov, V I; Dayton, D; De Mello, M; Deng, W S; Derevshchikov, A A; Dialinas, M; Díaz, H; De Young, P A; Didenko, L; Dimassimo, D; Dioguardi, J; Dominik, Wojciech; Drancourt, C; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Edwards, W R; Efimov, L G; Eggert, T; Emelyanov, V I; Engelage, J; Eppley, G; Erazmus, B; Etkin, A; Fachini, P; Feliciano, C; Ferenc, D; Ferguson, M I; Fessler, H; Finch, E; Fine, V; Fisyak, Yu; Flierl, D; Flores, I; Foley, Kenneth J; Fritz, D; Gagunashvili, N D; Gans, J; Gazdzicki, M; Germain, M; Geurts, F J M; Ghazikhanian, V; Gojak, C; Grabski, J; Grachov, O A; Grau, M; Greiner, D E; Greiner, L; Grigoriev, V; Grosnick, D P; Gross, J; Guilloux, G; Gushin, E M; Hall, J; Hallman, T J; Hardtke, D; Harper, G; Harris, J W; He, P; Heffner, M; Heppelmann, S; Herston, T; Hill, D; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Howe, M; Huang, H Z; Humanic, T J; Hümmler, H; Hunt, W; Hunter, J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Jacobson, S; Jared, R; Jensen, P; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kenney, V P; Khodinov, A; Klay, J L; Klein, S R; Klyachko, A A; Koehler, G; Konstantinov, A S; Kormilitsyne, V; Kotchenda, L; Kotov, I V; Kovalenko, A D; Krämer, M; Kravtsov, P; Krüger, K; Krupien, T; Kuczewski, P; Kühn, C E; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T J; Leonhardt, W; Leontiev, V M; Leszczynski, P; Le Vine, M J; Li, Q; Li, Z; Liaw, C J; Lin, J; Lindenbaum, S J; Lindenstruth, V; Lindstrom, P J; Lisa, M A; Liu, H; Ljubicic, T; Llope, W J; Lo Curto, G; Long, H; Longacre, R S; López-Noriega, M; Lopiano, D; Love, W A; Lutz, Jean Robert; Lynn, D; Madansky, L; Maier, R S; Majka, R; Maliszewski, A; Margetis, S; Marks, K; Marstaller, R; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; Matyushevsky, E A; McParland, C P; McShane, T S; Meier, J; Melnik, Yu M; Meshchanin, A P; Middlekamp, P; Mikhalin, N; Miller, B; Milosevich, Z; Minaev, N G; Minor, B; Mitchell, J; Mogavero, E; Moiseenko, V A; Moltz, D M; Moore, C F; Morozov, V; Morse, R; De Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Ngo, T; Nguyen, M; Nguyen, T; Nikitin, V A; Nogach, L V; Noggle, T; Norman, B; Nurushev, S B; Nussbaum, T; Nystrand, J; Odyniec, Grazyna Janina; Ogawa, A; Ogilvie, C A; Olchanski, K; Oldenburg, M; Olson, D; Ososkov, G A; Ott, G; Padrazo, D; Paic, G; Pandey, S U; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Pentia, M; Perevozchikov, V; Peryt, W; Petrov, V; Pinganaud, W; Pirogov, S; Platner, E D; Pluta, J; Polk, I; Porile, N T; Porter, J; Poskanzer, A M; Potrebenikova, E V; Prindle, D J; Pruneau, C A; Puskar-Pasewicz, J; Rai, G; Rasson, J E; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J; Renfordt, R E; Retière, F; Ridiger, A; Riso, J; Ritter, H G; Roberts, J B; Röhrich, D; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V L; Sakrejda, I; Sánchez, R; Sandler, Z; Sandweiss, J; Sappenfield, P; Saulys, A C; Savin, I A; Schambach, J; Scharenberg, R P; Scheblien, J; Scheetz, R; Schlüter, R; Schmitz, N; Schröder, L S; Schulz, M; Schüttauf, A; Sedlmeir, J; Seger, J E; Seliverstov, D M; Seyboth, J; Seyboth, P; Seymour, R; Shakaliev, E I; Shestermanov, K E; Shi, Y; Shimansky, S S; Shuman, D B; Shvetcov, V S; Skoro, G P; Smirnov, N; Smykov, L P; Snellings, R; Solberg, K; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, Reinhard; Stolpovsky, A; Stone, N; Stone, R; Strikhanov, M N; Stringfellow, B C; Ströbele, H; Struck, C; Suaide, A A P; Sugarbaker, E R; Suire, C; Symons, T J M; Takahashi, J; Tang, A H; Tarchini, A; Tarzian, J; Thomas, J H; Tikhomirov, V; Szanto de Toledo, A; Tonse, S R; Trainor, T; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V N; Tsai, O; Turner, K; Ullrich, T S; Underwood, D G; Vakula, I; Van Buren, G; Van der Molen, A; Vanyashin, A V; Vasilevskii, I M; Vasilev, A N; Vigdor, S E; Visser, G; Voloshin, S A; Vu, C; Wang, F; Ward, H; Weerasundara, D D; Weidenbach, R; Wells, R; Wenaus, T J; Westfall, G D; Whitfield, J P; Whitten, C; Wieman, H H; Willson, R; Wilson, K; Wirth, J; Wisdom, J; Wissink, S W; Witt, R; Wolf, J; Wood, L; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevsky, Yu V; Zhang, J; Zhang, W M; Zhu, J; Zimmerman, D; Zoulkarneev, R; Zubarev, A N

    2001-01-01

    Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at sqrt(s_NN)=130 GeV using the STAR TPC at RHIC. The elliptic flow signal, v_2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

  16. Leading Hadron Production in d+Au and 3He+Au collisions in the PHENIX experiment

    Science.gov (United States)

    Sakaguchi, Takao; Phenix Collaboration

    2017-08-01

    Neutral pions have been measured in 3He+Au collisions at √{sNN } = 200 GeV up to 20 GeV/c in the RHIC Year-2014 run. The nuclear modification factor RAA was measured and compared with that from d+Au collisions. The integrated RAA as a function of Npart was calculated for d+Au, 3He+Au and Au+Au collisions at √{sNN } = 200 GeV, and found to converge for Npart > 12, while a clear system ordering RdAu >RHeAu >RAuAu was observed for Npart > 12. The fractional momentum loss for the most central 3He+Au collisions was also estimated.

  17. Directed Flow of Light Nuclei in Au+Au Collisions at AGS Energies

    OpenAIRE

    E877 Collaboration; Barrette, J.; Bellwied, R.; Bennett, S.; Bersch, R.; Braun-Munzinger, P.; Chang, W. C.; Cleland, W. E.; Clemen, M.; Cole, J.; Cormier, T. M.; Dai, Y.; David, G.; Dee, J.; Dietzsch, O.

    1998-01-01

    Directed flow of deuterons, tritons, $^3$He, and $^4$He is studied in Au+Au collisions at a beam momentum of about 10.8 $A$ GeV/c. Flow of all particles is analyzed as a function of transverse momentum for different centralities of the collision. The directed flow signal, $v_1(p_t)$, is found to increase with particle mass. This mass dependence is strongest in the projectile rapidity region.

  18. Flow and bose-einstein correlations in Au-Au collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Manly, Steven; Back, B.B.; Baker, M.D.; Barton, D.S.; Betts, R.R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M.P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hofman, D.; Hollis, R.S.; Holyinski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C.M.; Lin, W.T.; Manly, S.; McLeod, D.; Michalowski, J.; Mignerey, A.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I.C.; Pernegger, H.; Reed, C.; Remsberg, L.P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S.G.; Steinberg, P.; Stephans, G.S.F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G.J. van; Verdier, R.; Wadsworth, B.; Wolfs, F.L.H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A.H.; Wyslouch, B

    2003-03-10

    Argonne flow and Bose-Einstein correlations have been measured in Au-Au collisions at {radical}S{sub NN} = 130 and 200 GeV using the PHOBOS detector at RHIC. The systematic dependencies of the flow signal on the transverse momentum, pseudorapidity, and centrality of the collision, as well as the beam energy are shown. In addition, results of a 3-dimensional analysis of two-pion correlations in the 200 GeV data are presented.

  19. D and $^{3}He$ production in $\\sqrt{s}$ = 130 GeV Au + Au collisions

    CERN Document Server

    Adler, C; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J T; Barannikova, O Yu; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A B; Cadman, R V; Caines, H; Calderón de la Barca-Sanchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Cormier, T M; Cramer, J G; Crawford, H J; De Mello, M; Deng, W S; Derevshchikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Finch, E; Fisyak, Yu; Flierl, D; Foley, Kenneth J; Fu, J; Gagunashvili, N D; Gans, J; Gaudichet, L; Germain, M; Geurts, F J M; Ghazikhanian, V; Grabski, J; Grachov, O A; Greiner, D E; Grigoriev, V; Guedon, M; Guschin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kisiel, A; Klay, J L; Klein, S R; Klyachko, A A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Krämer, M; Kravtsov, P; Krüger, K; Kuhn, C; Kulikov, A V; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamas-Valverde, J; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T J; Lednicky, R; Leontiev, V M; Le Vine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Ljubicic, T; Llope, W J; Lo Curto, G; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lynn, D; Majka, R; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnik, Yu M; Meshchanin, A P; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; De Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Oson, D; Paic, G; Pandey, S U; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevozchikov, V; Peryt, W; Petrov, V A; Platner, E D; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E V; Prindle, D J; Pruneau, C A; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V L; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schröder, L S; Schüttauf, A; Schweda, K; Seger, J E; Seliverstov, D M; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimansky, S S; Shvetcov, V S; Skoro, G P; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, Reinhard; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Struck, C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Tikhomirov, V; Trainor, T A; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T S; Underwood, D G; Van Buren, G; Van der Molen, A; Vanyashin, A V; Vasilevski, I M; Vasilev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Wenaus, T J; Westfall, G D; Whitten, C; Wieman, H H; Willson, R; Wissink, S W; Witt, R; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevsky, Yu V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N; 10.1103/PhysRevLett.87.262301

    2001-01-01

    The first measurements of light antinucleus production in Au + Au collisions at the Relativistic Heavy-Ion Collider are reported. The observed production rates for d and /sup 3/He are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at CERN SPS energy. These analyses also indicate that the 3He freeze-out volume is smaller than the d freeze-out volume. (22 refs).

  20. A first look at Au·Au collisions at RHIC energies using the PHOBOS ...

    Indian Academy of Sciences (India)

    A first look at Au·Au collisions at RHIC energies using the PHOBOS detector. BIRGER BACK1, for the PHOBOS Collaboration. M D Baker2, D S Barton2, R R Betts6, R Bindel7, A Budzanowski3, W Busza4,. A Carroll2, J Corbo2, M P Decowski4, E Garcia6, N George1, K Gulbrandsen4, S Gushue2,. C Halliwell6, J Hamblen8, ...

  1. Results from the PHOBOS Experiment on Au+Au Collisions at RHIC

    CERN Document Server

    Wozniak, K; Baker, M D; Barton, D S; Basilev, S N; Baum, R; Betts, R R; Bialas, A; Bindel, R; Bogucki, W; Budzanowski, A; Busza, W; Carroll, A; Ceglia, M; Chang, Y H; Chen, A E; Coghen, T; Conner, C L; Czyz, W; Dabrowski, B; Decowski, M P; Despet, M; Fita, P; Fitch, J; Friedl, M; Galuszka, K; Ganz, R E; García-Solis, E; George, N; Godlewski, J; Gomes, C; Griesmayer, E; Gulbrandsen, K H; Gushue, S; Halik, J; Halliwell, C; Haridas, P; Hayes, A; Heintzelman, G A; Henderson, C; Hollis, R; Holynski, R; Holzman, B; Johnson, E; Kane, J; Katzy, J M; Kita, W; Kotula, J; Kraner, H W; Kucewicz, W; Kulinich, P A; Law, C; Lemler, M A; Ligocki, T J; Lin, W T; Manly, S L; McLeod, D; Michalowski, J; Mignerey, A C; Mülmenstädt, J; Neal, M; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Patel, M; Pernegger, H; Plesko, M; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Ross, D; Rosenberg, L J; Ryan, J; Sanzgiri, A; Sarin, P; Sawicki, P; Scaduto, J; Shea, J; Sinacore, J; Skulski, W; Steadman, S G; Stephans, G S F; Steinberg, P; Straczek, A; Stodulski, M; Strek, M; Stopa, Z; Sukhanov, A; Surowiecka, K; Tang, J L; Teng, R; Trzupek, A; Vale, C J; van Nieuwenhuizen, G J; Verdier, R; Wadsworth, B; Wolfs, F L H; Wosiek, B; Wozniak, K; Wuosmaa, A H; Wyslouch, B; Zalewski, Kasper

    2001-01-01

    PHOBOS is one of four experiments studying the Au-Au interactions at RHIC. The data collected during the first few weeks after the RHIC start-up, using the initial configuration of the PHOBOS detector, were sufficient to obtain the first physics results for the most central collisions of Au nuclei at the center of mass energy of 56 and 130 AGeV. The pseudorapidity density of charged particles near midrapidity is shown and compared with data at lower energies and from $pp$ and $p\\bar{p}$ collisions. The progress of the analysis of the data is also presented.PHOBOS is one of four experiments studying the Au-Au interactions at RHIC. The data collected during the first few weeks after the RHIC start-up, using the initial configuration of the PHOBOS detector, were sufficient to obtain the first physics results for the most central collisions of Au nuclei at the center of mass energy of 56 and 130 AGeV. The pseudorapidity density of charged particles near midrapidity is shown and compared with data at lower energie...

  2. Measurements of direct photons in Au+Au collisions with PHENIX

    CERN Document Server

    Bannier, Benjamin

    2014-01-01

    The PHENIX experiment has published direct photon yields and elliptic flow coefficients $v_2$ from Au+Au collisions at RHIC energies. These results have sparked much theoretical discussion. The measured yields and flow parameters are difficult to reconcile in current model calculations of thermal radiation based on hydrodynamic time evolution of the collision volume. Our latest analyses which use high statistics data from the 2007 and 2010 runs allow the determination of direct photon yields with finer granularity in centrality and photon momentum and down to $p_T$ as low as 0.4 GeV/$c$. We will summarize the current status and present new results from PHENIX.

  3. Suppression of ϒ production in d+Au and Au+Au collisions at √(s{sub NN})=200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L. [AGH University of Science and Technology, Cracow (Poland); Adkins, J.K. [University of Kentucky, Lexington, KY, 40506-0055 (United States); Agakishiev, G. [Joint Institute for Nuclear Research, Dubna, 141 980 (Russian Federation); Aggarwal, M.M. [Panjab University, Chandigarh 160014 (India); Ahammed, Z. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Alekseev, I. [Alikhanov Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Alford, J. [Kent State University, Kent, OH 44242 (United States); Anson, C.D. [Ohio State University, Columbus, OH 43210 (United States); Aparin, A. [Joint Institute for Nuclear Research, Dubna, 141 980 (Russian Federation); Arkhipkin, D.; Aschenauer, E.C. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Averichev, G.S. [Joint Institute for Nuclear Research, Dubna, 141 980 (Russian Federation); Balewski, J. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Banerjee, A. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Barnovska, Z. [Nuclear Physics Institute AS CR, 250 68 Řež/Prague (Czech Republic); Beavis, D.R. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Bellwied, R. [University of Houston, Houston, TX, 77204 (United States); Bhasin, A. [University of Jammu, Jammu 180001 (India); Bhati, A.K. [Panjab University, Chandigarh 160014 (India); Bhattarai, P. [University of Texas, Austin, TX 78712 (United States); and others

    2014-07-30

    We report measurements of ϒ meson production in p+p, d+Au, and Au+Au collisions using the STAR detector at RHIC. We compare the ϒ yield to the measured cross section in p+p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for ϒ(1S+2S+3S) in the rapidity range |y|<1 in d+Au collisions of R{sub dAu}=0.79±0.24(stat.)±0.03(syst.)±0.10(p+p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au+Au collisions, we measure a nuclear modification factor of R{sub AA}=0.49±0.1(stat.)±0.02(syst.)±0.06(p+psyst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state ϒ mesons in Au+Au collisions. The additional suppression in Au+Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d+Au is still needed before any definitive statements about the nature of the suppression in Au+Au can be made.

  4. $\\Upsilon$ production in p+p and Au+Au collisions in STAR

    CERN Document Server

    Das, Debasish

    2008-01-01

    The study of quarkonium production in relativistic heavy ion collisions provides insight into the properties of the produced medium. The lattice studies show a sequential suppression of quarkonia states when compared to normal nuclear matter; which further affirms that a full spectroscopy including bottomonium can provide us a better thermometer for the matter produced under extreme conditions in relativistic heavy ion collisions. With the completion of the STAR Electromagnetic Calorimeter and with the increased luminosity provided by RHIC in Run 6 and 7, the study of $\\Upsilon$ production via the di-electron channel becomes possible. We present the results on $\\Upsilon$ measurements in p+p collisions (from Run 6) along with the first results from Au+Au collisions (in Run 7) at $\\sqrt{s_{\\rm{NN}}} = 200$ GeV from the STAR experiment.

  5. Nuclear Stopping in Central Au+Au Collisions at RHIC Energies

    Directory of Open Access Journals (Sweden)

    Ying Yuan

    2014-01-01

    Full Text Available Nuclear stopping in central Au+Au collisions at relativistic heavy-ion collider (RHIC energies is studied in the framework of a cascade mode and the modified ultrarelativistic quantum molecular dynamics (UrQMD transport model. In the modified mode, the mean field potentials of both formed and “preformed” hadrons (from string fragmentation are considered. It is found that the nuclear stopping is increasingly influenced by the mean-field potentials in the projectile and target regions with the increase of the reaction energy. In the central region, the calculations of the cascade model considering the modifying factor can describe the experimental data of the PHOBOS collaboration.

  6. Azimuthal Anisotropy in U+U and Au+Au Collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandin, A V; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cervantes, M C; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, H Z; Huang, B; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, W; Li, Y; Li, C; Li, Z M; Li, X; Li, X; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, L; Ma, R; Ma, Y G; Ma, G L; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D L; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Peterson, A; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Pruthi, N K; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, S; Raniwala, R; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Sharma, M K; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Skoby, M J; Smirnov, D; Smirnov, N; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B J; Sun, X; Sun, X M; Sun, Z; Sun, Y; Surrow, B; Svirida, D N; Szelezniak, M A; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A N; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbaek, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, F; Wang, Y; Wang, H; Wang, J S; Wang, Y; Wang, G; Webb, G; Webb, J C; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, Y F; Xu, N; Xu, Z; Xu, Q H; Xu, H; Yang, Y; Yang, Y; Yang, C; Yang, S; Yang, Q; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, X P; Zhang, J B; Zhang, J; Zhang, Z; Zhang, S; Zhang, Y; Zhang, J L; Zhao, F; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2015-11-27

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v_{2}{2} and v_{2}{4}, for charged hadrons from U+U collisions at sqrt[s_{NN}]=193  GeV and Au+Au collisions at sqrt[s_{NN}]=200  GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v_{2}{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v_{2} vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

  7. Au Cern, premières collisions de protons hier

    CERN Multimedia

    Galeazzi, Juliette

    2009-01-01

    "Hier, les scientifiques du monde entier ont salué le redémarrage du LHC, grand collisionneur de hadrons, au Cern à Genève. Après quatorze mois d'arrêt, à la suite d'une panne, les expériences ont pris et les premières collisions ont eu lieu" (2 pages)

  8. Measurement of the dielectron continuum in p+p and Au+Au collisions at RHIC

    CERN Document Server

    Dahms, Torsten

    2010-01-01

    PHENIX has measured the e^+e^- pair continuum in sqrt(s_NN) = 200 GeV Au+Au and p+p collisions over a wide range of mass and transverse momenta. While the p+p data in the mass range below the phi meson are well described by known contributions from light meson decays, the Au+Au minimum bias inclusive mass spectrum shows an enhancement by a factor of 4.7 +/- 0.4(stat)} +/- 1.5(syst) +/- 0.9(model) in the mass range 0.15collision.

  9. PHENIX Measurements of Single Electrons from Charm and Bottom Decays at Midrapidity in Au + Au Collisions

    Science.gov (United States)

    McGlinchey, D.

    2016-12-01

    Heavy quarks are an ideal probe of the quark gluon plasma created in heavy ion collisions. They are produced in the initial hard scattering and therefore experience the full evolution of the medium. PHENIX has previously measured the modification of heavy quark production in Au+Au collisions at √{sNN} = 200 GeV via electrons from semileptonic decays, which indicated substantial modifications of the parent hadron momentum distribution. The PHENIX barrel silicon vertex detector (VTX), installed in 2011, allows for the separation of electrons from charm and bottom hadron decays through the use of displaced vertex measurements. These proceedings present the results of the completed analysis of the 2011 data set using the VTX.

  10. PHENIX results on low pT direct photons in Au + Au collisions

    Science.gov (United States)

    Petti, Richard

    2016-12-01

    Since soft photons are unmodified once produced in heavy ion collisions, they give information about the entire thermal evolution of the medium. Excess photon yield over the expectation from initial hard scattering has been measured by PHENIX. In addition, PHENIX has measured a large azimuthal anisotropy, v2, of these soft photons with respect to the reaction plane. The large yield and v2 have been difficult to describe quantitatively and raise important questions about the early time dynamics in the medium. It is thus important to make more differential measurements to distinguish various potential explanations for this thermal photon puzzle. In this proceedings, we present yields, v2, and v3 of direct photons from √{sNN} = 200 GeV Au + Au collisions.

  11. Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au+Au collisions at RHIC.

    Science.gov (United States)

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-08-15

    We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at sqrt[s(NN)]=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.

  12. Common suppression pattern of η and π0 mesons at high transverse momentum in Au+Au collisions at VsNN=200 GeV

    NARCIS (Netherlands)

    Peitzmann, T.

    2006-01-01

    Inclusive transverse momentum spectra of η mesons have been measured within pT=2–10 GeV/c at midrapidity by the PHENIX experiment in Au+Au collisions at VsNN=200 GeV. In central Au+Au the η yields are significantly suppressed compared to peripheral Au+Au, d+Au, and p+p yields scaled by the

  13. PHENIX results on flow observables in asymmetric Cu + Au collisions

    Science.gov (United States)

    Schaefer, B.

    2016-12-01

    Measurements of anisotropic flow from Cu+Au √{sNN} = 200 GeV collisions in PHENIX at RHIC in 2012 are presented for inclusive charged particles and identified hadrons π±, K±, p, and p ‾ at midrapidity. Fourier coefficients characterizing the azimuthal distribution of produced particles with respect to the event plane measured at forward rapidity are examined over a broad range of pT and collision centrality. Directed, elliptic, and triangular moments (v1, v2, v3 as functions of pT) all exhibit mass ordering. Comparisons are made to Cu+Cu and Au+Au systems as well as to hydrodynamical and transport model calculations [A. Adare, et al., "Measurements of directed, elliptic, and triangular flow in Cu+Au collisions at √{sNN} = 200 GeV", arXiv:1509.07784.]. Unlike v2 and v3, v1 decreases with centrality, mass ordering is seen for all three, and v2 and v3 with respect to transverse momentum feature common scaling with 1 / (εnNpart1/3).

  14. Temperature measurement of fragment emitting systems in Au+Au 35 MeV/nucleon collisions

    Science.gov (United States)

    Milazzo, P. M.; Vannini, G.; Azzano, M.; Fontana, D.; Margagliotti, G. V.; Mastinu, P. F.; Rui, R.; Tonetto, F.; Colonna, N.; Botvina, A.; Bruno, M.; D'agostino, M.; Fiandri, M. L.; Gramegna, F.; Iori, I.; Moroni, A.; Dinius, J. D.; Gaff, S.; Gelbke, C. K.; Glasmacher, T.; Huang, M. J.; Kunde, G. J.; Lynch, W. G.; Martin, L.; Montoya, C. P.; Xi, H.

    1998-08-01

    We report on the results of experiments performed to investigate the Au+Au 35 MeV/nucleon reaction. The reaction products generated in the disassembly of the unique source formed in central collisions and those coming from the decay of the quasiprojectile in peripheral and midperipheral ones (five different impact parameters) were identified through a careful data selection based on the study of energy and angular distributions. The excitation energies of the fragment sources have been extracted through a calorimetric method and by means of a comparison with model calculations. The nuclear temperatures of these decaying systems have been measured from the relative isotopic abundances and, also for central collisions, from the relative populations of excited states. The temperatures of the quasiprojectile disassembling systems are slowly increasing going towards smaller impact parameter. The relationship between temperature and excitation energy seems to be almost independent of the characteristics of the emitting source. The extracted caloric curve shows a slow monotonic increase with increasing excitation energy. A comparison with data derived from Au fragmentation at much higher incident energies is discussed.

  15. On Productions of Net-Baryons in Central Au-Au Collisions at RHIC Energies

    Directory of Open Access Journals (Sweden)

    Ya-Hui Chen

    2015-01-01

    Full Text Available The transverse momentum and rapidity distributions of net-baryons (baryons minus antibaryons produced in central gold-gold (Au-Au collisions at 62.4 and 200 GeV are analyzed in the framework of a multisource thermal model. Each source in the model is described by the Tsallis statistics to extract the effective temperature and entropy index from the transverse momentum distribution. The two parameters are used as input to describe the rapidity distribution and to extract the rapidity shift and contribution ratio. Then, the four types of parameters are used to structure some scatter plots of the considered particles in some three-dimensional (3D spaces at the stage of kinetic freeze-out, which are expected to show different characteristics for different particles and processes. The related methodology can be used in the analyses of particle production and event holography, which are useful for us to better understand the interacting mechanisms.

  16. Direct virtual photon production in Au plus Au collisions at root s(NN)=200 GeV STAR Collaboration

    Czech Academy of Sciences Publication Activity Database

    Adamczyk, L.; Bielčík, J.; Bielčíková, Jana; Chaloupka, P.; Federič, Pavol; Federičová, P.; Harlenderová, A.; Kocmánek, Martin; Kvapil, J.; Lidrych, J.; Rusňák, Jan; Rusňáková, O.; Šaur, Miroslav; Šimko, Miroslav; Šumbera, Michal; Trzeciak, B. A.

    2017-01-01

    Roč. 770, JUL (2017), s. 451-458 ISSN 0370-2693 R&D Projects: GA ČR GA13-20841S Institutional support: RVO:61389005 Keywords : STAR collaboration * transverse mementum * Au Au collisions Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.807, year: 2016

  17. Two-pion correlations in Au + Au collisions at 10.8 GeV/c per nucleon

    CERN Document Server

    Barrette, J; Bennett, S; Bersch, R; Braun-Munzinger, P; Chang, W C; Cleland, W E; Cole, J D; Cormier, T M; Dávid, G; Dee, J; Dietzsch, O; Drigert, M W; Gilbert, S J; Hall, J R; Hemmick, T K; Herrmann, N; Hong, B H; Jiang, C L; Johnson, S C; Kwon, Y; Lacasse, R; Lukaszew, A; Li, Q; Ludlam, Thomas W; McCorkle, S; Mark, S K; Mathéus, R D; Miskowiec, D; O'Brien, E; Panitkin, S; Piazza, T; Pollack, M E; Pruneau, C A; Rao, M N; Rosati, M; Da Silva, N C; Sedykh, S N; Sonnadara, U; Stachel, J J; Takagui, E M; Trzaska, M; Voloshin, S A; Vongpaseuth, T B; Wang, G; Wessels, J P; Woody, C L; Xu, N; Zhang, Y; Zou, C

    1997-01-01

    Two-particle correlation functions for positive and negative pions have been measured in Au+Au collisions at 10.8~GeV/c per nucleon. The data were analyzed using one- and three-dimensional correlation functions. From the results of the three-dimensional fit the phase space density of pions was calculated. It is consistent with local thermal equilibrium.

  18. Two-pion correlations in Au+Au collisions at 10.8 GeV/c per nucleon

    OpenAIRE

    E877 Collaboration; Barrette, J.; Bellwied, R.; Bennett, S.; Bersch, R.; Braun-Munzinger, P.; Chang, W. C.; Cleland, W. E.; Cole, J. D.; Cormier, T. M.; David, G.; Dee, J.; Dietzsch, O.; Drigert, M. W.; Gilbert, S.

    1997-01-01

    Two-particle correlation functions for positive and negative pions have been measured in Au+Au collisions at 10.8~GeV/c per nucleon. The data were analyzed using one- and three-dimensional correlation functions. From the results of the three-dimensional fit the phase space density of pions was calculated. It is consistent with local thermal equilibrium.

  19. Identified particles in Au+Au collisions at {radical}S{sub NN} = 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Wosiek, Barbara; Back, B.B.; Baker, M.D.; Barton, D.S.; Betts, R.R.; Ballintijn, M.; Bickley, A.A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M.P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G.A.; Henderson, C.; Hofman, D.J.; Hollis, R.S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C.M.; Manly, S.; McLeod, D.; Michalowski, J.; Mignerey, A.C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I.C.; Pernegger, H.; Reed, C.; Remsberg, L.P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S.G.; Steinberg, P.; Stephans, G.S.F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G.J. van; Verdier, R.; Wadsworth, B.; Wolfs, F.L.H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A.H.; Wysouch, B

    2003-03-10

    The yields of identified particles have been measured at RHIC for Au+Au collisions at {radical}S{sub NN} = 200 GeV using the PHOBOS spectrometer. The ratios of antiparticle to particle yields near mid-rapidity are presented. The first measurements of the invariant yields of charged pions, kaons and protons at very low transverse momenta are also shown.

  20. Bimodality in binary Au + Au collisions from 60 to 100 MeV/u

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, M.; Tamain, B.; Bougault, R. [Caen Univ., Lab. de Physique Corpusculaire, IN2P3-CNRS, ISMRA, 14 (France)] [and others

    2003-03-01

    The deexcitation of quasi-projectiles (QP) released in binary Au on Au collisions as been studied from 60 to 100 MeV/u. Bimodality between two different decay patterns has been observed for intermediate violence collisions. The main experimental result is that the system jumps from one mode to the other on a narrow range of energy deposit and/or impact parameter. The sorting of the events (according to the violence of the collision) has been provided by the perpendicular energy of the light charged particles emitted on the quasi-target side. Such a sorting prevents spurious autocorrelation effects between the sorting variable and the observed mechanism. The two modes of the QP decay correspond on the one side to residue or fission fragments production, and on the other side to the multifragmentation channel. A detailed study has been performed in order to try to establish the origin of the observed bimodality in disentangling dynamical or geometrical effects from bulk matter properties linked with a liquid-gas type phase transition. The whole set of data is coherent with a dominant role of the deposited excitation energy as it is expected from theoretical arguments.(lattice gas model) in the framework of a liquid-gas phase transition picture. (authors)

  1. Partonic flow and ϕ-meson production in Au+Au collisions at VsNN=200 = GeV

    NARCIS (Netherlands)

    Bai, Y.; Benedosso, F.; Botje, M.A.J.; Grebenyuk, O.; Mischke, A.; Peitzmann, T.; Russcher, M.J.; Snellings, R.J.M.; van der Kolk, N.

    2007-01-01

    We present first measurements of the ϕ-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from √sNN=200  GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the ϕ meson is consistent with the trend observed for mesons. The ratio of the yields

  2. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L. [AGH University of Science and Technology, Cracow 30-059 (Poland); Adkins, J.K. [University of Kentucky, Lexington, KY, 40506-0055 (United States); Agakishiev, G. [Joint Institute for Nuclear Research, Dubna, 141 980 (Russian Federation); Aggarwal, M.M. [Panjab University, Chandigarh 160014 (India); Ahammed, Z. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Alekseev, I. [Alikhanov Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Aparin, A. [Joint Institute for Nuclear Research, Dubna, 141 980 (Russian Federation); Arkhipkin, D.; Aschenauer, E.C. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Averichev, G.S. [Joint Institute for Nuclear Research, Dubna, 141 980 (Russian Federation); Bai, X. [University of Illinois at Chicago, Chicago, IL 60607 (United States); Bairathi, V. [National Institute of Science Education and Research, Bhubaneswar 751005 (India); Banerjee, A. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Bellwied, R. [University of Houston, Houston, TX 77204 (United States); Bhasin, A. [University of Jammu, Jammu 180001 (India); Bhati, A.K. [Panjab University, Chandigarh 160014 (India); Bhattarai, P. [University of Texas, Austin, TX 78712 (United States); Bielcik, J. [Czech Technical University in Prague, FNSPE, Prague, 115 19 (Czech Republic); Bielcikova, J. [Nuclear Physics Institute AS CR, 250 68 Řež/Prague (Czech Republic); Bland, L.C. [Brookhaven National Laboratory, Upton, NY 11973 (United States); and others

    2015-12-17

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  3. Di-hadron correlations with identified leading hadrons in 200 GeV Au+Au and d+Au collisions at STAR

    Directory of Open Access Journals (Sweden)

    L. Adamczyk

    2015-12-01

    Full Text Available The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au+Au and minimum-bias d+Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au+Au data with respect to the d+Au reference and the absence of such an enhancement for leading non-pions (protons and kaons are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  4. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L; Adkins, JK; Agakishiev, G; Aggarwal, MM; Ahammed, Z; Alekseev, I; Aparin, A; Arkhipkin, D; Aschenauer, EC; Averichev, GS; Bai, X; Bairathi, V; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, AK; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, LC; Bordyuzhin, IG; Bouchet, J; Brandenburg, D; Brandin, AV; Bunzarov, I; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, JM; Cebra, D; Cervantes, MC; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, X; Chen, JH; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, HJ; Das, S; De Silva, LC; Debbe, RR; Dedovich, TG; Deng, J; Derevschikov, AA; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, JL; Draper, JE; Du, CM; Dunkelberger, LE; Dunlop, JC; Efimov, LG; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, CE; Fulek, L; Gagliardi, CA; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, DS; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, JW; He, L; Heppelmann, S; Heppelmann, S; Hirsch, A; Hoffmann, GW; Hofman, DJ; Horvat, S; Huang, T; Huang, B; Huang, HZ; Huang, X; Huck, P

    2015-10-23

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  5. Jet-hadron correlations in √[s(NN)]=200  GeV p+p and central Au+Au collisions.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-03-28

    Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

  6. Dielectron production in Au$+$Au collisions at $\\sqrt{s_{NN}}$=200 GeV

    CERN Document Server

    Adare, A; Ajitanand, N N; Akiba, Y; Akimoto, R; Alexander, J; Alfred, M; Al-Ta'ani, H; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Bathe, S; Baublis, V; Baumgart, S; Bazilevsky, A; Beaumier, M; Beckman, S; Belmont, R; Berdnikov, A; Berdnikov, Y; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Butsyk, S; Campbell, S; Castera, P; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Csanád, M; Csörgő, T; Dairaku, S; Danley, D; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Edwards, S; Efremenko, Y V; Engelmore, T; Enokizono, A; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Gallus, P; Garg, P; Garishvili, A; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Guo, L; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamilton, H F; Han, S Y; Hanks, J; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Hemmick, T K; Hester, T; Hill, J C; Hollis, R S; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Iordanova, A; Isenhower, D; Issah, M; Ivanishchev, D; Jacak, B V; Javani, M; Jezghani, M; Jia, J; Jiang, X; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kamin, J; Kanda, S; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D J; Kim, E -J; Kim, G W; Kim, H J; Kim, K -B; Kim, M; Kim, Y -J; Kim, Y K; Kimelman, B; Kinney, E; Kiss, Á; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Komatsu, Y; Komkov, B; Koster, J; Kotchetkov, D; Kotov, D; Král, A; Krizek, F; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, B; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Leitgab, M; Lewis, B; Li, X; Lim, S H; Levy, L A Linden; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; Masumoto, S; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Milov, A; Mishra, D K; Mitchell, J T; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Mohapatra, S; Montuenga, P; Moon, H J; Moon, T; Morrison, D P; Motschwiller, S; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagashima, K; Nagle, J L; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Nederlof, A; Netrakanti, P K; Nihashi, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; O'Brien, E; Ogilvie, C A; Okada, K; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J S; Park, S; Park, S K; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Qu, H; Rak, J; Ramson, B J; Ravinovich, I; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rowan, Z; Rubin, J G; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sano, M; Sarsour, M; Sato, S; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seidl, R; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Snowball, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Themann, H; Tieulent, R; Timilsina, A; Todoroki, T; Tomášek, L; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Tsuji, T; Vale, C; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; White, A S; White, S N; Winter, D; Wolin, S; Woody, C L; Wysocki, M; Xia, B; Xue, L; Yalcin, S; Yamaguchi, Y L; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J H; Yoon, I; You, Z; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S; Zou, L

    2015-01-01

    We present measurements of $e^+e^-$ production at midrapidity in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}$ = 200 GeV. The invariant yield is studied within the PHENIX detector acceptance over a wide range of mass ($m_{ee} <$ 5 GeV/$c^2$) and pair transverse momentum ($p_T$ $<$ 5 GeV/$c$), for minimum bias and for five centrality classes. The \\ee yield is compared to the expectations from known sources. In the low-mass region ($m_{ee}=0.30$--0.76 GeV/$c^2$) there is an enhancement that increases with centrality and is distributed over the entire pair \\pt range measured. It is significantly smaller than previously reported by the PHENIX experiment and amounts to $2.3\\pm0.4({\\rm stat})\\pm0.4({\\rm syst})\\pm0.2^{\\rm model}$ or to $1.7\\pm0.3({\\rm stat})\\pm0.3({\\rm syst})\\pm0.2^{\\rm model}$ for minimum bias collisions when the open-heavy-flavor contribution is calculated with {\\sc pythia} or {\\sc mc@nlo}, respectively. The inclusive mass and $p_T$ distributions as well as the centrality dependence are well repr...

  7. Measurement of Direct Photons in Ultra-Relativistic Au+Au Collisions

    Science.gov (United States)

    Gong, Haijiang

    Direct photons provide a tool to study the different stages of a heavy ion collision, especially the formation of the quark-gluon-plasma (QGP), without being influenced by the strong reaction and hadronization processes. The yield of direct photons can be determined from the inclusive photon yield and the photon yield from hadronic decays. At low pT, where a significant fraction of direct photon is expected to come from the thermalized medium of deconfined quarks and gluons and interacting hadrons, the measurement is very challenging. These so-called thermal photons carry information about the initial temperature of the medium. We present a new analysis technique that was developed to improve direct photon production measurement in the low and medium pT range. The technique was applied to the PHENIX Run4 Au+Au sqrt(sNN)=200GeV/c collisions dataset. It uses strict particle identification (PID) in the Electromagnetic Calorimeter (EMCal) and a charged particle veto to extract a clean photon signal. These photons are then tagged with EMCal photon candidates with loose PID cuts, which can be reconstructed with high efficiency, to determine the fraction of photons originating from neutral pion decays. Most systematic uncertainties and detector effects cancel in this method. The results are compared with recent PHENIX direct photon measurement through external conversion method and theoretical calculation predicting thermal photon production.

  8. Charged-particle multiplicity at mid-rapidity in Au–Au collisions at ...

    Indian Academy of Sciences (India)

    The particle density at mid-rapidity is an essential global variable for the characterization of nuclear collisions at ultra-relativistic energies. It provides information about the initial conditions and energy density reached in these collisions. The pseudorapidity densities of charged particles at mid-rapidity in Au + Au collisions at ...

  9. PHENIX results on low-mass dileptons in Au + Au collisions with the Hadron Blind Detector

    Science.gov (United States)

    Makek, M.

    2016-12-01

    We present e+e- continuum measurement in Au+Au collisions at √{sNN} = 200 GeV from the RHIC 2010 run with the Hadron Blind Detector upgrade of PHENIX. The measurement reaches a high purity of the electron sample of ≥ 95% at all centralities and provides an excellent qualitative and quantitative understanding of the background. The e+e- invariant yields show an enhancement in the low-mass region (mee = 0.30 - 0.76 GeV /c2) compared to the expectations from hadronic sources, but not as large as the one previously reported by PHENIX. The observed excess is well reproduced by models incorporating the broadening of the ρ meson due to scattering off baryons in the hot hadronic gas. The measured invariant yields in the intermediate-mass region (mee = 1.2 - 2.8 GeV /c2) leave room for additional sources when compared to the cocktail dominated by the semileptonic decays of heavy flavor mesons.

  10. Proton-Λ correlations in central Au+Au collisions at VsNN=200 GeV

    NARCIS (Netherlands)

    Bai, Y.; Botje, M.A.J.|info:eu-repo/dai/nl/070139032; Grebenyuk, O.|info:eu-repo/dai/nl/304848883; Mischke, A.|info:eu-repo/dai/nl/325781435; Peitzmann, T.|info:eu-repo/dai/nl/304833959; Russcher, M.J.|info:eu-repo/dai/nl/304847844; Snellings, R.J.M.|info:eu-repo/dai/nl/165585781; van der Kolk, N.

    2006-01-01

    We report on p-Λ,p-Λ̅ ,p̅ -Λ, and p̅ -Λ̅ correlation functions constructed in central Au-Au collisions at √sNN=200 GeV by the STAR experiment at RHIC. The proton and lambda source size is inferred from the p-Λ and p̅ -Λ̅ correlation functions. It is found to be smaller than the pion source size also

  11. Energy and system size dependence of phi meson production in Cu+Cu and Au+Au collisions

    Energy Technology Data Exchange (ETDEWEB)

    STAR Coll

    2008-10-28

    We study the beam-energy and system-size dependence of {phi} meson production (using the hadronic decay mode {phi} {yields} K{sup +}K{sup -}) by comparing the new results from Cu + Cu collisions and previously reported Au + Au collisions at {radical}s{sub NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from midrapidity (|y| < 0.5) for 0.4 < p{sub T} < 5 GeV/c. At a given beam energy, the transverse momentum distributions for {phi} mesons are observed to be similar in yield and shape for Cu + Cu and Au + Au colliding systems with similar average numbers of participating nucleons. The {phi} meson yields in nucleus-nucleus collisions, normalized by the average number of participating nucleons, are found to be enhanced relative to those from p + p collisions with a different trend compared to strange baryons. The enhancement for {phi} mesons is observed to be higher at {radical}s{sub NN} = 200 GeV compared to 62.4 GeV. These observations for the produced {phi}(s{bar s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.

  12. Antiproton production in Au + Au collisions at 11.7 A{center_dot}GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Hiroyuki [Tokyo Univ. (Japan)

    1997-02-01

    We investigated the dependence of antiproton yields on the number of wounded projectile nucleons (N{sub proj}). The dN/dy/N{sub proj} of antiprotons with the beam energy correction is almost constant from p+A to Si+A collisions, while it decreases in Au+Au collisions to 30-60% of the constant. Next, we have compared dependence of ratios of dN/dy, p-bar/{pi}{sup -}, p/{pi}{sup -}, K{sup -}/{pi}{sup -}, K{sup +}/{pi}{sup -}, and {pi}{sup +}/{pi}{sup -} at 1.2Au+Au collisions. Only the ratio of p-bar/{pi}{sup -} decreases rapidly, while the ratios of p/{pi}{sup -}, K{sup +}/{pi}{sup -}, and K{sup -}/{pi}{sup -} increase, and {pi}{sup +}/{pi}{sup -} stays constant. These observations suggest that in the AGS energy regime, the absorption effect of antiprotons in Au+Au collisions is much stronger than in p+A and Si+A collisions. We have compared the antiproton data with the RQMD model. In RQMD, antiprotons are produced initially from multi-step excitation processes and some of them are absorbed by nucleons with free NN-bar annihilation cross sections. RQMD reproduces overall tendencies of antiproton yields from p+A to Au+Au collisions within 50%. Finally, we explored the relation between baryon densities and antiproton yields in A+A collisions. We used a model in a static participant volume with the RQMD initial production and the absorption length with the free NN-bar annihilation cross section. In the model, only the antiprotons produced around the surface of the participant volume can survive. The model reproduces the scaling of experimental antiproton yields with the 2/3 power of the number of participants. By comparing the model with the experimental data, it is found that the ratio of the mean baryon density to the surface baryon density is 3-4 independent of collision systems. (J.P.N.). 109 refs.

  13. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-01

    Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

  14. Comparison of the space-time extent of the emission source in $d$$+$Au and Au$+$Au collisions at $\\sqrt{s_{{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Black, D; Blau, D S; Bok, J; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; del Valle, Z Conesa; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Do, J H; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; D'Orazio, L; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Grim, G; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guragain, H; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Han, S Y; Hanks, J; Hartouni, E P; Hasegawa, S; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hoshino, T; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; Jin, J; Johnson, B M; Jones, T; Joo, E; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kihara, K; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, H -J; Kim, M; Kim, S H; Kim, Y -J; Kim, Y K; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kofarago, M; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Lee, S H; Leitch, M J; Leite, M A L; Leitgab, M; Leitner, E; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, A J; Milov, A; Mishra, D K; Mishra, M; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nouicer, R; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Koop, J D Orjuela; Oskarsson, A; Ouchida, M; Ozaki, H; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Riveli, N; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stepanov, M; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, D; Thomas, T L; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, M; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; Whitaker, S; White, S N; Winter, D; Wolin, S; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoon, I; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhang, C; Zhou, S; Zolin, L

    2014-01-01

    Two-pion interferometry measurements in $d$$+$Au and Au$+$Au collisions at $\\sqrt{s_{{NN}}}=200$ GeV are used to extract and compare the Gaussian source radii R$_{{\\rm out}}$, R$_{{\\rm side}}$, and R$_{{\\rm long}}$, which characterize the space-time extent of the emission sources. The comparisons, which are performed as a function of collision centrality and the mean transverse momentum for pion pairs, indicate strikingly similar patterns for the $d$$+$Au and Au$+$Au systems. They also indicate a linear dependence of R$_{{\\rm side}}$ on the initial transverse geometric size $\\bar{R}$, as well as a smaller freeze-out size for the $d$$+$Au system. These patterns point to the important role of final-state rescattering effects in the reaction dynamics of $d$$+$Au collisions.

  15. Measurement of direct photons in Au+Au collisions at √(s(NN))=200 GeV.

    Science.gov (United States)

    Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Jamel, A; Alexander, J; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Chujo, T; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Das, K; David, G; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Fields, D E; Fleuret, F; Fokin, S L; Forestier, B; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fung, S-Y; Gadrat, S; Gastineau, F; Germain, M; Glenn, A; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-Å; Hachiya, T; Hadj Henni, A; Haggerty, J S; Hagiwara, M N; Hamagaki, H; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hiejima, H; Hill, J C; Hobbs, R; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hur, M G; Ichihara, T; Iinuma, H; Imai, K; Imrek, J; Inaba, M; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kaneta, M; Kang, J H; Kawagishi, T; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Leitch, M J; Leite, M A L; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Masui, H; Matathias, F; McCain, M C; McGaughey, P L; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mitchell, J T; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakamura, T; Newby, J; Nguyen, M; Norman, B E; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Omiwade, O O; Oskarsson, A; Otterlund, I; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Samsonov, V; Sato, H D; Sato, S; Sawada, S; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Thomas, T L; Togawa, M; Tojo, J; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tuli, S K; Tydesjö, H; Tyurin, N; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vértesi, R; Vinogradov, A A; Vznuzdaev, E; Wagner, M; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yanovich, A; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zimányi, J; Zolin, L

    2012-10-12

    We report the measurement of direct photons at midrapidity in Au+Au collisions at √(s(NN))=200 GeV. The direct photon signal was extracted for the transverse momentum range of 4 GeV/cphotons from the inclusive photon sample. The direct photon nuclear modification factor R(AA) was calculated as a function of p(T) for different Au+Au collision centralities using the measured p+p direct photon spectrum and compared to theoretical predictions. R(AA) was found to be consistent with unity for all centralities over the entire measured p(T) range. Theoretical models that account for modifications of initial direct photon production due to modified parton distribution functions in Au and the different isospin composition of the nuclei predict a modest change of R(AA) from unity. They are consistent with the data. Models with compensating effects of the quark-gluon plasma on high-energy photons, such as suppression of jet-fragmentation photons and induced-photon bremsstrahlung from partons traversing the medium, are also consistent with this measurement.

  16. Charm Meson Production in Au-Au Collisions at √ SNN = 200 Gev at Rhic

    Science.gov (United States)

    Vanfossen, Joseph A., Jr.

    dense surrounding medium, as the quarks traverse it. Such suppression is an indicator that the medium generated in relativistic heavy-ion collisions is strongly interacting. Theoretical models were successful in describing the suppression of light quarks but under-predicted the observed heavy-flavor suppression. The data triggered a new effort in modeling where theorists started taking into account the energy loss due to elastic collisions between the traversing parton and the surrounding medium. To fully understand the interplay between elastic and inelastic collision mechanisms of light and heavy partons and the hot medium, we needed precise data on heavy flavor production. Also, in order to be able to access the parent's kinematic information, one needs to perform a full topological reconstruction of the parent's decay. This will also allow for the separation of charm and bottom mesons. The study of D0 mesons, the lightest mesons with a charm quark, can be used to study the properties of the medium created in collisions, such as the density, flow, and thermalization of the medium. This dissertation presents an attempt to measure D0/D0bar ratios and D0 meson production in Au+Au collisions at sqrt(s_NN) = 200 GeV from fully reconstructed decays. For this purpose, we used a silicon tracker in STAR consisting of the Silicon Vertex Tracker (SVT) and the Silicon Strip Detector (SSD), along with the Time Projection Chamber (TPC) in a special run in the year 2007. We have developed new calibration and microvertexing techniques in the data analysis. We performed full secondary vertex reconstruction, to topologically reconstruct the secondary vertex of the D0 meson in the decay channel D0 -> K- + pi+ (B.R. = 3.89% and ct = 123 µm) and then performed a standard invariant mass analysis. At the same time we used a new tool (TMVA) in high energy physics for optimizing the signal to background ratio. However, precise measurements of open heavy flavor are difficult to obtain with

  17. Pion Interferometry of square root of (s(NN)) =130 GeV Au + Au collisions at RHIC.

    Science.gov (United States)

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Bossingham, R; Boucham, A; Brandin, A; Cadman, R V; Caines, H; Calderón De La Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Conin, L; Cormier, T M; Cramer, J G; Crawford, H J; DeMello, M; Deng, W S; Derevschikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grabski, J; Grachov, O; Greiner, D; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamas-Valverde, J; Lamont, M A; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Li, Q; Lindenbaum, S J; Lisa, M A; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lynn, D; Majka, R; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; McShane, T S; Meissner, F; Melnick, Y; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Pinganaud, W; Platner, E; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schweda, K; Schmitz, N; Schroeder, L S; Schüttauf, A; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Stroebele, H; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Sumbera, M; Symons, T J; Szanto De Toledo, A; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Tikhomirov, V; Trainor, T A; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Wenaus, T; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2001-08-20

    Two-pion correlation functions in Au+Au collisions at square root of [s(NN)] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in square root of [s(NN)].

  18. Elliptic flow due to charged hadrons for Au+Au collisions at RHIC energy 62.4 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Somani Ajit, E-mail: ajit.somani@gmail.com [Department of Physics, Suresh Gyan Vihar University, Jaipur, Rajasthan, INDIA (Presently working at Govt. Polytechnic College, Hanumangarh, Rajasthan, INDIA) (India); Sudhir, Bhardwaj [Govt. College of Engineering & Technology, Bikaner, Rajasthan (India); Ashish, Agnihotri [Department of Physics, SBCET, Jaipur, Rajasthan (India)

    2016-05-06

    Elliptic flow is an important observable in search of Quark Gluon Plasma. The elliptic flow parameter dependence on centrality due to charged hadrons were studied using events generated by event generator AMPT at center of mass energy of 62.4 GeV per nucleon pair for Au+Au collisions. This study performed for pseudorapidity range from −0.35 to 0.35 and transverse momentum bins p{sub t} = 0.2 to 1 GeV/c and 1 to 2 GeV/c. We compared the results obtained from simulated data and RHIC-PHENIX data.

  19. The Rapidity Distributions and the Thermalization Induced Transverse Momentum Distributions in Au-Au Collisions at RHIC Energies

    Directory of Open Access Journals (Sweden)

    Zhi-Jin Jiang

    2017-01-01

    Full Text Available It is widely believed that the quark-gluon plasma (QGP might be formed in the current heavy ion collisions. It is also widely recognized that the relativistic hydrodynamics is one of the best tools for describing the process of expansion and hadronization of QGP. In this paper, by taking into account the effects of thermalization, a hydrodynamic model including phase transition from QGP state to hadronic state is used to analyze the rapidity and transverse momentum distributions of identified charged particles produced in heavy ion collisions. A comparison is made between the theoretical results and experimental data. The theoretical model gives a good description of the corresponding measurements made in Au-Au collisions at RHIC energies.

  20. Detailed study of high-pT neutral pion suppression and azimuthal anisotropy in Au+Au collisions at VsNN=200 GeV

    NARCIS (Netherlands)

    Peitzmann, T.|info:eu-repo/dai/nl/304833959

    2007-01-01

    Measurements of neutral pion (π0) production at midrapidity in VsNN=200 GeV Au+Au collisions as a function of transverse momentum, pT, collision centrality, and angle with respect to reaction plane are presented. The data represent the final π0 results from the PHENIX experiment for the first RHIC

  1. Systematic studies of the centrality dependence of soft photon production in Au+Au collision with PHENIX

    CERN Document Server

    Bannier, Benjamin

    2014-01-01

    Since the earliest days of Heavy Ion Physics thermal soft photon radiation emitted during the reaction had been theorized as a smoking gun signal for formation of a quark-gluon plasma and as a tool to characterize its properties. In recent years the existence of excess photon radiation in heavy ion collisions over the expectation from initial hard interactions has been confirmed at both RHIC and LHC energies by PHENIX and ALICE respectively. There the radiation has been found to exhibit elliptic flow $v_2$ well above what can currently be reconciled with a picture of early emission from a plasma phase. During the 2007 and 2010 Au+Au runs PHENIX has measured a high purity sample of soft photons down to $p_T>0.4\\,\\text{GeV}/c$ using an external conversion method. We present recent systematic studies by PHENIX from that sample on the centrality dependence of the soft photon yield, and elliptic and triangular flow $v_2$ and $v_3$ in Au+Au collisions which fill in the experimental picture and enable discrimination...

  2. Bayesian model comparison for one-dimensional azimuthal correlations in 200GeV AuAu collisions

    Directory of Open Access Journals (Sweden)

    Eggers Hans C.

    2016-01-01

    Full Text Available In the context of data modeling and comparisons between different fit models, Bayesian analysis calls that model best which has the largest evidence, the prior-weighted integral over model parameters of the likelihood function. Evidence calculations automatically take into account both the usual chi-squared measure and an Occam factor which quantifies the price for adding extra parameters. Applying Bayesian analysis to projections onto azimuth of 2D angular correlations from 200 GeV AuAu collisions, we consider typical model choices including Fourier series and a Gaussian plus combinations of individual cosine components. We find that models including a Gaussian component are consistently preferred over pure Fourier-series parametrizations, sometimes strongly so. For 0–5% central collisions the Gaussian-plus-dipole model performs better than Fourier Series models or any other combination of Gaussian-plus-multipoles.

  3. Single electrons from semi-leptonic charm and bottom hadron decays in Au+Au collisions at PHENIX

    Science.gov (United States)

    Hachiya, Takashi

    2016-08-01

    Heavy quarks are clean probes to explore the nature of strongly coupled quark gluon plasma created in high energy heavy ion collisions. The strong suppression of single electrons from semi-leptonic decays of heavy flavor hadrons was observed. To further understand the heavy quark suppressions, PHENIX installed the silicon vertex detector (VTX) which allows us to measure the bottom and charm productions separately from measurement of displaced tracks. For the first time, we observed the electrons from bottom hadron decays are less suppressed than those from charms for 3 < pT < 4 GeV/c and are similarly strongly suppressed for higher pT in minimum bias Au+Au collisions at √sNN = 200 GeV. We present the results of separated bottom and charm productions using the 2011 dataset with the VTX.

  4. Charged jet reconstruction in Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV at RHIC

    CERN Document Server

    ,

    2014-01-01

    Jets represent an important tool to explore the properties of the hot and dense nuclear matter created in heavy-ion collisions. However, full jet reconstruction in such events is a challenging task due to extremely large and fluctuating background, which generates a large population of combinatorial jets that overwhelm the true hard jet population. In order to carry out accurate, data-driven jet measurements over a broad kinematic range in such conditions of small signal to background, we use several novel approaches in order to measure inclusive charged jet distributions and semi-inclusive charged jet distributions recoiling from a high pT hadron trigger in central Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV.

  5. PHENIX results on fluctuations and Bose-Einstein correlations in Au + Au collisions from the RHIC Beam Energy Scan

    Science.gov (United States)

    Garg, Prakhar

    2016-12-01

    The RHIC Beam Energy Scan focuses on mapping the QCD phase diagram and pinpointing the location of a possible critical end point. Bose-Einstein correlations and event-by-event fluctuations of conserved quantities, measured as a function of centrality and collision energy, are promising tools in these studies. Recent lattice QCD and statistical thermal model calculations predict that higher-order cumulants of the fluctuations are sensitive indicators of the phase transition. Products of these cumulants can be used to extract the freeze-out parameters [A. Bazavov et al., Phys. Rev. Lett. 109, 192302 (2012)] and to locate the critical point [M. A. Stephanov, K. Rajagopal and E. V. Shuryak, Phys. Rev. D 60, 114028 (1999)]. Two-pion interferometry measurements are predicted to be sensitive to potential softening of the equation of state and prolonged emission duration close to the critical point [S. Pratt, Phys. Rev. Lett. 53, 1219 (1984)]. We present recent PHENIX results on fluctuations of net-charge using high-order cumulants and their products in Au+Au collisions at √{sNN} = 7.7- 200 GeV, and measurement of two-pion correlation functions and emission-source radii in Cu+Cu and Au+Au collisions at several beam energies. The extracted source radii are compared to previous measurements at RHIC and LHC in order to study energy dependence of the specific quantities sensitive to expansion velocity and emission duration. Implications for the search of a critical point and baryon chemical potentials at various collision energies are discussed.

  6. Open heavy flavor measurements in d+Au collisions at PHENIX experiment

    Directory of Open Access Journals (Sweden)

    Lim Sanghoon

    2014-04-01

    Full Text Available The heavy quarks produced in the early stage of heavy-ion collisions are very effective probes of the dense partonic medium produced at RHIC. PHENIX has the ability to measure heavy quark production through single electrons in the central arm spectrometers (|η| < 0.35 and single muons in the forward (backward muon spectrometers (1.2 < |η| < 2.2. As these single leptons are from open heavy-flavor meson semi-leptonic decays, initial state cold nuclear matter effects on heavy quark production can be probed by measuring the single leptons in d+Au collisions. PHENIX have observed a large enhancement of heavy-flavor electrons in d+Au collisions at mid-rapidity, which indicates strong CNM effects on heavy quark production, in contrast to the suppression observed in Au+Au collisions. Measurement of single muons from open heavy flavor in d+Au collisions at forward (backward rapidity provide detailed look into rapidity dependent CNM effects as well as the low (high x parton distribution function within Au nucleus. We discuss recent PHENIX heavy flavor measurements and how they expand our understanding of CNM effects and contribute to the interpretation of other results in heavy-ion collisions.

  7. Analysis of d/p ratio in Au+Au collisions from the E866 experiment at the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Shea, Y.; Garcia-Solis, E.J.; Stanskas, P.J. [Univ. of Maryland, College Park, MD (United States)

    1996-02-01

    High energy nucleus-nucleus collisions are a great interest as a means of creating a new state of matter. The transition of nuclear matter to quark matter is expected to result in a strongly interacting region that lives for a long time and expands to a large volume. In order to understand the properties of the collision region, it is important to gather information experimentally on the lifetime and thermodynamic attributes such as temperature, volume, density, and entropy of the collision region. Deuteron production by phase space coalescence is particularly interesting because it can be used as a probe in studying the space-time structure of the heavy ion collisions. In the hot and dense participant region, a proton and a neutron coalesce when their relative momentum is small. The deuteron density in momentum space is proportional to the proton density squared in momentum space at equal momenta per nucleon, assuming proton and neutron density to be identical. The motivation here is to study the properties of the coalesced deuterons formed in the participant region of Au-Au collisions at 11.6 GeV/c. The d/p ratio as a function of centrality is studied in hopes of gaining information about any change in the size of the participant zone which could lead to the effort of searching for the Quark-Gluon-Plasma at the AGS. The results shown here is very preliminary and the work is in progress.

  8. Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au+Au Collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Aparin, A; Arkhipkin, D; Aschenauer, E C; Attri, A; Averichev, G S; Bai, X; Bairathi, V; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandenburg, J D; Brandin, A V; Bunzarov, I; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Chakaberia, I; Chaloupka, P; Chang, Z; Chatterjee, A; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A I; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Heppelmann, S; Hirsch, A; Hoffmann, G W; Horvat, S; Huang, T; Huang, X; Huang, B; Huang, H Z; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jentsch, A; Jia, J; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikoła, D P; Kisel, I; Kisiel, A; Kochenda, L; Koetke, D D; Kosarzewski, L K; Kraishan, A F; Kravtsov, P; Krueger, K; Kumar, L; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, X; Li, C; Li, X; Li, Y; Li, W; Lin, T; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, R; Ma, G L; Ma, Y G; Ma, L; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Matis, H S; McDonald, D; McKinzie, S; Meehan, K; Mei, J C; Minaev, N G; Mioduszewski, S; Mishra, D; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Niida, T; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V A; Olvitt, D; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Pile, P; Pluta, J; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Pruthi, N K; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, S; Raniwala, R; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, A; Sharma, B; Sharma, M K; Shen, W Q; Shi, Z; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Singha, S; Skoby, M J; Smirnov, N; Smirnov, D; Solyst, W; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B; Sun, Z; Sun, X M; Sun, Y; Surrow, B; Svirida, D N; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A; Thäder, J; Thomas, J H; Timmins, A R; Tlusty, D; Todoroki, T; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbæk, F; Vokal, S; Voloshin, S A; Vossen, A; Wang, F; Wang, G; Wang, J S; Wang, H; Wang, Y; Wang, Y; Webb, G; Webb, J C; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y; Xiao, Z G; Xie, W; Xie, G; Xin, K; Xu, Y F; Xu, Q H; Xu, N; Xu, H; Xu, Z; Xu, J; Yang, S; Yang, Y; Yang, Y; Yang, C; Yang, Y; Yang, Q; Ye, Z; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, X P; Zhang, Y; Zhang, J; Zhang, J; Zhang, S; Zhang, S; Zhang, Z; Zhang, J B; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2016-03-18

    We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from sqrt[s_{NN}]=7.7 to 200 GeV. The third harmonic v_{3}^{2}{2}=⟨cos3(ϕ_{1}-ϕ_{2})⟩, where ϕ_{1}-ϕ_{2} is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη=η_{1}-η_{2}. Nonzero v_{3}^{2}{2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v_{3}^{2}{2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v_{3}^{2}{2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v_{3}^{2}{2} for central collisions shows a minimum near sqrt[s_{NN}]=20  GeV.

  9. Collective effects in Au(100-800 AMeV) + Au semi-central collisions; Effets collectifs dans les collisions semi-centrales Au(100-800 AMeV) + Au

    Energy Technology Data Exchange (ETDEWEB)

    Crochet, P.

    1996-04-04

    The present work has been carried out in the framework of the experimental program of the FOPI collaboration. It is devoted to a systematic study of the different forms of collective expansion of nuclear matter in semi-central Au+Au collisions at incident energies ranging from 100 AMeV to 800 AMeV. The aim is to investigate the influence of compressional effects, momentum dependence of the nuclear interaction and nucleon-nucleon cross section on the observed phenomena. Important changes in the reaction mechanisms are evidenced, in particular at low incident energies where one observes, on the one hand, a transition from an enhanced in-plane emission to a preferential out-of-plane emission pattern and, on the other hand, a strong reduction of the directed in-plane component. Experimental results are compared to the predictions of the Quantum Molecular Dynamics (QMD) model for different parametrizations of the nuclear interaction. (author).

  10. Electric fields and chiral magnetic effect in Cu+Au collisions

    Directory of Open Access Journals (Sweden)

    Wei-Tian Deng

    2015-03-01

    Full Text Available The non-central Cu+Au collisions can create strong out-of-plane magnetic fields and in-plane electric fields. By using the HIJING model, we study the general properties of the electromagnetic fields in Cu+Au collisions at 200 GeV and their impacts on the charge-dependent two-particle correlator γq1q2=〈cos⁡(ϕ1+ϕ2−2ψRP〉 (see main text for definition which was used for the detection of the chiral magnetic effect (CME. Compared with Au+Au collisions, we find that the in-plane electric fields in Cu+Au collisions can strongly suppress the two-particle correlator or even reverse its sign if the lifetime of the electric fields is long. Combining with the expectation that if γq1q2 is induced by elliptic-flow driven effects we would not see such strong suppression or reversion, our results suggest to use Cu+Au collisions to test CME and understand the mechanisms that underlie γq1q2.

  11. Anomalous \\phi Meson Suppression in Au+Au Collisions at \\sqrt{s_{NN}}=200 GeV Measured by the PHENIX Experiment at RHIC

    CERN Document Server

    Naglis, Maxim

    2009-01-01

    The PHENIX experiment at RHIC has measured the \\phi-meson production at mid-rapidity in p+p, d+Au, Cu+Cu and Au+Au collisions at \\sqrt{s_{NN}}=200 GeV via the K^+K^- decay mode. The transverse momentum spectra of the \\phi-meson and the nuclear modification factor as a function of centrality are reviewed here.

  12. Ω and ϕ in Au + Au collisions at and 11.5 GeV from a multiphase transport model

    Science.gov (United States)

    Ye, Y. J.; Chen, J. H.; Ma, Y. G.; Zhang, S.; Zhong, C.

    2017-08-01

    Within the framework of a multiphase transport model, we study the production and properties of Ω and ϕ in Au + Au collisions with a new set of parameters for and with the original set of parameters for . The AMPT model with string melting provides a reasonable description at , while the default AMPT model describes the data well at . This indicates that the system created at top RHIC energy is dominated by partonic interactions, while hadronic interactions become important at lower beam energy, such as . The comparison of N(Ω++Ω-)/[2N(ϕ)] ratio between data and calculations further supports the argument. Our calculations can generally describe the data of nuclear modification factor as well as elliptic flow. Supported by National Natural Science Foundation of China (11421505, 11520101004, 11220101005, 11275250, 11322547), Major State Basic Research Development Program in China (2014CB845400, 2015CB856904) and Key Research Program of Frontier Sciences of CAS (QYZDJSSW-SLH002)

  13. Azimuthal correlations of high-p{sub T} photons and hadrons in Au+Au collisions at STAR

    Energy Technology Data Exchange (ETDEWEB)

    Dietel, T.

    2006-07-01

    The STAR experiment observed a modification of the azimuthal correlations between a trigger particle and associated particles in central Au+Au collisions, where trigger particles with 4 GeV

  14. Delta-phi Delta-eta Correlations in Central Au+Au Collisions atsqrt sNN = 200 Gev

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson,B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai, Y.; Balewski,J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland,L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderonde la Barca Sanchez, M.; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; Kollegger, T.; et al.

    2006-07-07

    We report charged-particle pair correlation analyses in thespace of Delta -phi (azimuth) and Delta-eta (pseudo-rapidity), forcentral Au + Au collisions at sqrt sNN = 200 GeV in the STAR detector.The analysis involves unlike-sign charge pairs and like-sign chargepairs, which are transformed into charge-dependent (CD) signals andcharge-independent (CI) signals. We present detailed parameterizations ofthe data. A model featuring dense gluonic hot spots as first proposed byvan Hove predicts that the observables under investigation would havesensitivity to such a substructure should it occur, and the model alsomotivates selection of transverse momenta in the range 0.8

  15. In-medium reduction of the η' mass √sNN = 200 GeV Au+Au collisions

    Directory of Open Access Journals (Sweden)

    Sziklai J.

    2011-04-01

    Full Text Available A reduction of the mass of the η' (958 meson may indicate the restoration of the UA(1 symmetry in a hot and dense hadronic matter, corresponding to the return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a combined PHENIX and STAR data set on the intercept parameter of the two-pion Bose-Einstein correlation functions, as measuremed in √sNN = 200 GeV Au+Au collisions at RHIC. To describe this combined PHENIX and STAR dataset, an in-medium η' mass reduction of at least 200 MeV is needed, at the 99.9 % confidence level in a broad model class of resonance multiplicities. Energy, system size and centrality dependence of the observed effect is also discussed.

  16. Identified particle production, azimuthal anisotropy, and interferometry measurements in Au+Au collisions at sqrt(s)NN = 9.2 GeV

    NARCIS (Netherlands)

    Abelev, B.I.; Benedosso, F.; Braidot, E|info:eu-repo/dai/nl/304840874; Mischke, A.|info:eu-repo/dai/nl/325781435; Peitzmann, T.|info:eu-repo/dai/nl/304833959; Russcher, M.J.|info:eu-repo/dai/nl/304847844

    2010-01-01

    We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au+Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance solenoidal tracker

  17. Thermodynamical features of multifragmentation in peripheral Au + Au collisions at 35 A MeV

    Science.gov (United States)

    D'Agostino, M.; Botvina, A. S.; Bruno, M.; Bonasera, A.; Bondorf, J. P.; Bougault, R.; Désesquelles, P.; Geraci, E.; Gulminelli, F.; Iori, I.; Le Neindre, N.; Margagliotti, G. V.; Mishustin, I. N.; Moroni, A.; Pagano, A.; Vannini, G.

    1999-04-01

    The distribution of fragments produced in events involving the multifragmentation of excited sources is studied for peripheral Au + Au reactions at 35 A MeV. The Quasi-Projectile has been reconstructed from its de-excitation products. An isotropic emission in its rest frame has been observed, indicating that an equilibrated system has been formed. The excitation energy of the Quasi-Projectile has been determined via calorimetry. A new event by event effective thermometer is proposed based on the energy balance. A peak in the energy fluctuations is observed related to the heat capacity suggesting that the system undergoes a liquid-gas type phase transition at an excitation energy ˜ 5 A MeV and a temperature 4-6 MeV, dependent on the freeze-out hypothesis. By analyzing different regions of the Campiplot, the events associated with the liquid and gas phases as well as the critical region are thermodynamically characterized. The critical exponents, τ, β, γ, extracted from the high moments of the charge distribution are consistent with a liquid-gas type phase transition.

  18. High p$\\perp$ inclusive charged hadron distributions in Au+Au collisions at √sNN = 130 GeV at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bum Jin [Univ. of Texas, Austin, TX (United States)

    2003-08-01

    This thesis reports the measurement of the inclusive charged particle (h+ + h-) p$\\perp$ spectra for 1.7 < p$\\perp$ < 6 GeV/c at midrapidity (|η| < 0.5) as a function of various centrality classes in Au+Au collisions at √sNN = 130 GeV. Hadron suppression is observed relative to both scaled NN and peripheral Au+Au reference data, possibly indicating non-Abelian radiative energy loss in a hot, dense medium.

  19. Transverse momentum and centrality dependence of high-ptnon-photonic electron suppression in Au+Au collisions at $\\sqrt{s_{NN}}$= 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2006-07-11

    The STAR collaboration at RHIC reports measurements of theinclusive yield of non-photonic electrons, which arise dominantly fromsemi-leptonic decays of heavy flavor mesons, over a broad range oftransverse momenta (1.2Au, and AuAucollisions at sqrt sNN = 200 GeV. The non-photonic electron yieldexhibits unexpectedly large suppression in central AuAu collisions athigh pt, suggesting substantial heavy quark energy loss at RHIC. Thecentrality and \\pt dependences of the suppression provide constraints ontheoretical models of suppression.

  20. Beam energy dependence of moments of the net-charge multiplicity distributions in Au+Au collisions at RHIC.

    Science.gov (United States)

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Balewski, J; Banerjee, A; Barnovska, Z; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Grosnick, D; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hajkova, O; Hamed, A; Han, L-X; Haque, R; Harris, J W; Hays-Wehle, J P; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Korsch, W; Kotchenda, L; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lima, L M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Munhoz, M G; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Oliveira, R A N; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Peterson, A; Pile, P; Planinic, M; Pluta, J; Plyku, D; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandacz, A; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; deSouza, U G; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-29

    We report the first measurements of the moments--mean (M), variance (σ(2)), skewness (S), and kurtosis (κ)--of the net-charge multiplicity distributions at midrapidity in Au+Au collisions at seven energies, ranging from sqrt[sNN]=7.7 to 200 GeV, as a part of the Beam Energy Scan program at RHIC. The moments are related to the thermodynamic susceptibilities of net charge, and are sensitive to the location of the QCD critical point. We compare the products of the moments, σ(2)/M, Sσ, and κσ(2), with the expectations from Poisson and negative binomial distributions (NBDs). The Sσ values deviate from the Poisson baseline and are close to the NBD baseline, while the κσ(2) values tend to lie between the two. Within the present uncertainties, our data do not show nonmonotonic behavior as a function of collision energy. These measurements provide a valuable tool to extract the freeze-out parameters in heavy-ion collisions by comparing with theoretical models.

  1. Photon-hadron correlations and jet fragmentation in Au+Au 200 GeV collisions measured with PHENIX

    Science.gov (United States)

    Rowan, Zachary; Phenix Collaboration

    2017-09-01

    Because of the observed jet suppression in heavy ion collisions, typical jet reconstruction, or high pt hadron jet tagging, results in a surface bias. Prompt photons, produced in the Compton scattering and annihilation of quarks, easily escape the quark gluon plasma and, when used to tag away side jets, introduce no such bias. However a bias towards quark jets is introduced as the Compton production process dominates, making these tagging methods complimentary. With the additional benefit of the photon pT being a suitable proxy for the jet pT, photon-hadron correlations in Au+Au 200 GeV collisions are analyzed with PHENIX. Through the analysis of mixed events with reaction plane classification, the background contribution to the azimuthal correlation function can be removed, revealing an away side jet peak. By characterizing the structure in multiple centrality classes; photon emission angles measured with respect to reaction plane orientation; and photon energies, the collision geometry and relative levels of bremsstrahlung and fragmentation photons can be varied, allowing for a detailed study of path length dependent jet fragmentation. The status of this analysis will be discussed.

  2. Open heavy flavor measurements in $d$$+$Au collisions at PHENIX experiment

    CERN Document Server

    ,

    2014-01-01

    The heavy quarks produced in the early stage of heavy-ion collisions are very effective probes of the dense partonic medium produced at RHIC. PHENIX has the ability to measure heavy quark production through single electrons in the central arm spectrometers ($|\\eta|<0.35$) and single muons in the forward (backward) muon spectrometers ($1.2<|\\eta|<2.2$). As these single leptons are from open heavy-flavor meson semi-leptonic decays, initial state cold nuclear matter effects on heavy quark production can be probed by measuring the single leptons in $d$$+$Au collisions. PHENIX have observed a large enhancement of heavy-flavor electrons in $d$$+$Au collisions at mid-rapidity, which indicates strong CNM effects on heavy quark production, in contrast to the suppression observed in Au$+$Au collisions. Measurement of single muons from open heavy flavor in $d$$+$Au collisions at forward (backward) rapidity provide detailed look into rapidity dependent CNM effects as well as the low (high) $x$ parton distributio...

  3. Charged particle multiplicity near mid-rapidity in central Au+Au collisions at $\\sqrt{s}$ = 56 and 130 AGeV

    CERN Document Server

    Back, B B; Barton, D S; Basilev, S N; Baum, R; Betts, R R; Bialas, A; Bindel, R; Bogucki, W; Budzanowski, A; Busza, W; Carroll, A S; Ceglia, M; Chang, Y H; Chen, A E; Coghen, T; Conner, C L; Czyz, W; Dabrowski, B; Decowski, M P; Despet, M; Fita, P; Fitch, J; Friedl, M; Galuszka, K; Ganz, R E; García-Solis, E; George, N; Godlewski, J; Gomes, C; Griesmayer, E; Gulbrandsen, K H; Gushue, S; Halik, J; Halliwell, C; Haridas, P; Hayes, A; Heintzelman, G A; Henderson, C; Hollis, R; Holynski, R; Holzman, B; Johnson, E; Kane, J; Katzy, J M; Kita, W; Kotula, J; Kraner, H W; Kucewicz, W; Kulinich, P A; Law, C; Lemler, M A; Ligocki, T J; Lin, W T; Manly, S L; McLeod, D; Michalowski, J; Mignerey, A C; Mülmenstädt, J; Neal, M; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Patel, M; Pernegger, H; Plesko, M; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Ross, D; Rosenberg, L J; Ryan, J; Sanzgiri, A; Sarin, P; Sawicki, P; Scaduto, J; Shea, J; Sinacore, J; Skulski, W; Steadman, S G; Stephans, G S F; Steinberg, P; Straczek, A; Stodulski, M; Strek, M; Stopa, Z; Sukhanov, A; Surowiecka, K; Tang, J L; Teng, R; Trzupek, A; Vale, C J; van Nieuwenhuizen, G J; Verdier, R; Wadsworth, B; Wolfs, F L H; Wosiek, B; Wozniak, K; Wuosmaa, A H; Wyslouch, B; Zalewski, Kasper

    2000-01-01

    We present the first measurement of pseudorapidity densities of primary charged particles near mid-rapidity in Au+Au collisions at $\\sqrt{s} =$ 56 and 130 AGeV. For the most central collisions, we find the charged particle pseudorapidity density to be $dN/d\\eta |_{|\\eta|<1} = 408 \\pm 12 {(stat)} \\pm 30 {(syst)}$ at 56 AGeV and $555 \\pm 12 {(stat)} \\pm 35 {(syst)}$ at 130 AGeV, values that are higher than any previously observed in nuclear collisions. Compared to proton-antiproton collisions, our data show an increase in the pseudorapidity density per participant by more than 40% at the higher energy.

  4. Energy dependence of J/ψ production in Au+Au collisions at sNN=39,62.4 and 200GeV

    Directory of Open Access Journals (Sweden)

    L. Adamczyk

    2017-08-01

    Full Text Available The inclusive J/ψ transverse momentum spectra and nuclear modification factors are reported at mid-rapidity (|y|<1.0 in Au+Au collisions at sNN = 39, 62.4 and 200 GeV taken by the STAR experiment. A suppression of J/ψ production, with respect to the production in p+p scaled by the number of binary nucleon–nucleon collisions, is observed in central Au+Au collisions at these three energies. No significant energy dependence of nuclear modification factors is found within uncertainties. The measured nuclear modification factors can be described by model calculations that take into account both suppression of direct J/ψ production due to the color screening effect and J/ψ regeneration from recombination of uncorrelated charm–anticharm quark pairs.

  5. Studying photon-jet correlation in pp, dAu collisions in PHENIX

    Science.gov (United States)

    Jin, Jiamin

    2004-10-01

    PHENIX has measured direct photon production in Au+Au collisions at √s_NN = 200 GeV/c[1]. A large enhancement over the meson decay background is seen in central Au+Au collisions at transverse momentum p_T>6 GeV/c This provides an opportunity to probe the dense medium using jets tagged by direct photons. Most of these direct photons are produced in q +g(barq) arrow γ + q(g) processes. Since photons penetrate the dense medium with greatly reduced interactions compared to hadrons, they will carry roughly the same amount of energy as the scattered quarks, and thus provide an excellent measure of the energy and direction of the tagged jet. However, due to the large amount of underlying background and limited PHENIX acceptance, it is very difficult to identify both the direct photon and tagged jet. We have developed an isolation cut technique to separate direct photon candidates from meson decay photons. These candidates are then correlated with other particles to search for the tagged jet signal, where we use the event mixing technique to subtract the combinatoric background. Results will be shown from a feasibility study of the isolation cuts in giving a clean sample of direct photons. Preliminary results on the properties of the jets tagged by direct photons in p+p and d+Au collisions will also be presented. [1] J. Frantz, "PHENIX Direct Photons in 200 GeV p+p and Au+Au Collisions", nucl-ex/0404006

  6. Centrality, Rapidity And Transverse-Momentum Dependence of Cold Nuclear Matter Effects on J/Psi Production in D Au, Cu Cu And Au Au Collisions at S(NN)**(1/2)

    Energy Technology Data Exchange (ETDEWEB)

    Ferreiro, E.G.; /Santiago de Compostela U.; Fleuret, F.; /Ecole Polytechnique; Lansberg, J.P.; /Ecole Polytechnique /SLAC; Rakotozafindrabe, A.; /SPhN, DAPNIA, Saclay

    2011-11-11

    We have carried out a wide study of Cold Nuclear Matter (CNM) effects on J/{Psi} = production in dAu, CuCu and AuAu collisions at {radical}s{sub NN} = 200 GeV. We have studied the effects of three different gluon-shadowing parameterizations, using the usual simplified kinematics for which the momentum of the gluon recoiling against the J/{Psi} is neglected as well as an exact kinematics for a 2 {yields} 2 process, namely g + g {yields} J/{psi} + g as expected from LO pQCD. We have shown that the rapidity distribution of the nuclear modification factor R{sub dAu}, and particularly its anti-shadowing peak, is systematically shifted toward larger rapidities in the 2 {yields} 2 kinematics, irrespective of which shadowing parameterization is used. In turn, we have noted differences in the effective final-state nuclear absorption needed to fit the PHENIX dAu data. Taking advantage of our implementation of a 2 {yields} 2 kinematics, we have also computed the transverse momentum dependence of the nuclear modification factor, which cannot be predicted with the usual simplified kinematics. All the corresponding observables have been computed for CuCu and AuAu collisions and compared to the PHENIX and STAR data. Finally, we have extracted the effective nuclear absorption from the recent measurements of RCP in dAu collisions by the PHENIX collaboration.

  7. A first look at Au· Au collisions at RHIC energies using the PHOBOS ...

    Indian Academy of Sciences (India)

    Charged particle multiplicity; ultra-relativistic heavy-ion collisions. ... These observables include the charged-particle multiplicity measured as a function of beam energy, pseudo-rapidity, and centrality of the collision. A unique ... This high value suggests that an almost baryon-free region has been produced in the collisions.

  8. Pion Interferometry in Au+Au and Cu+Cu Collisions at sqrt sNN = 62.4 and 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    STAR Collaboration; Abelev, B.I.

    2009-08-24

    We present a systematic analysis of two-pion interferometry in Au+Au collisions at {radical}sNN = 62.4 GeV and Cu+Cu collisions at {radical}sNN = 62.4 and 200 GeV using the STAR detector at RHIC. The multiplicity and transverse momentum dependences of the extracted correlation lengths (radii) are studied. The scaling with charged particle multiplicity of the apparent system volume at final interaction is studied for the RHIC energy domain. The multiplicity scaling of the measured correlation radii is found to be independent of colliding system and collision energy.

  9. Hydrodynamic modeling of 3He–Au collisions at sNN=200 GeV

    Directory of Open Access Journals (Sweden)

    Piotr Bożek

    2015-07-01

    Full Text Available Collective flow and femtoscopy in ultrarelativistic 3He–Au collisions are investigated within the 3+1-dimensional (3+1D viscous event-by-event hydrodynamics. We evaluate elliptic and triangular flow coefficients as functions of the transverse momentum. We find the typical long-range ridge structures in the two-particle correlations in the relative azimuth and pseudorapidity, in the pseudorapidity directions of both Au and 3He. We also make predictions for the pionic interferometric radii, which decrease with the transverse momentum of the pion pair. All features found hint on collectivity of the dynamics of the system formed in 3He–Au collisions, with hydrodynamics leading to quantitative agreement with the up-to-now released data.

  10. Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at √S(NN)=200 GeV.

    Science.gov (United States)

    Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Alford, J; Anderson, B D; Anson, C D; Arkhipkin, D; Averichev, G S; Balewski, J; Barnby, L S; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Braidot, E; Brandin, A V; Brovko, S G; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Cai, X Z; Caines, H; Sánchez, M Calderón de la Barca; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chung, P; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Cui, X; Leyva, A Davila; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; de Souza, R Derradi; Didenko, L; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunlop, J C; Efimov, L G; Elnimr, M; Engelage, J; Eppley, G; Estienne, M; Eun, L; Evdokimov, O; Fachini, P; Fatemi, R; Fedorisin, J; Fersch, R G; Filip, P; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Geurts, F; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O G; Grosnick, D; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hajkova, O; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Huang, B; Huang, H Z; Humanic, T J; Huo, L; Igo, G; Jacobs, W W; Jena, C; Joseph, J; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Kizka, V; Klein, S R; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kravtsov, P; Krueger, K; Kumar, L; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, L; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lima, L M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Longacre, R S; Lu, Y; Lukashov, E V; Luo, X; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Meschanin, A; Milner, R; Minaev, N G; Mioduszewski, S; Mitrovski, M K; Mohammed, Y; Mohanty, B; Mondal, M M; Morozov, B; Morozov, D A; Munhoz, M G; Mustafa, M K; Naglis, M; Nandi, B K; Nasim, Md; Nayak, T K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Oliveira, R A N; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Pei, H; Peitzmann, T; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Plyku, D; Poljak, N; Porter, J; Poskanzer, A M; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ruan, L; Rusnak, J; Sahoo, N R; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Selyuzhenkov, I; Seyboth, P; Shah, N; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Shou, Q Y; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Solanki, D; Sorensen, P; deSouza, U G; Spinka, H M; Srivastava, B; Stanislaus, T D S; Steadman, S G; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; de Toledo, A Szanto; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Tlusty, D; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Witzke, W; Wu, Y F; Xiao, Z; Xie, W; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yang, Y; Yepes, P; Yip, K; Yoo, I-K; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, J B; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y

    2012-02-17

    We report transverse momentum (p(T)≤15  GeV/c) spectra of π(±), K(±), p, p[over ¯], K(S)(0), and ρ(0) at midrapidity in p+p and Au+Au collisions at √S(NN)=200  GeV. Perturbative QCD calculations are consistent with π(±) spectra in p+p collisions but do not reproduce K and p(p[over ¯]) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au+Au at p(T)≳8  GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.

  11. Multiple production of mesons in Au+Au and Pb+Pb collisions

    CERN Document Server

    Guptaroy, P; Bhattacharya, D P; Bhattacharya, S

    2003-01-01

    The study presented here pertains to the model-based analyses for production of some important charged secondaries in lead-lead and gold-gold collisions at AGS, SPS and RHIC energies. We examine the role of a particular version of the Sequential Chain Model (SCM) in interpreting the data on the production of only the secondary mesons of the most abundant variety in relativistic nucleus-nucleus collisions. The initial results derived for basic pp collisions have been transformed into the corresponding cases for nucleus-nucleus collisions through the appropriate physical-mathematical formalisms. The agreement between the model of choice and the measured data for the most important varieties of mesons in the two above-stated nuclear collisions could so far be rated to be barely modest. This is presumably due to our neglect of the effects of rescattering and cascading, while we choose to obtain only the first-order results in the initial attempt. (47 refs).

  12. Soft photon production in central 200 GeV nucleon S-32+Au collisions

    NARCIS (Netherlands)

    Aggarwal, MM; Angelis, ALS; Antonenko, [No Value; Awes, TC; Badyal, SK; Barlag, C; Bhalla, KB; Bhatia, VS; Blume, C; Bock, D; Bohne, EM; Bucher, D; Buijs, A; Chattopadhyay, S; Claussen, A; Clewing, G; Das, AC; Devanand, [No Value; Donni, P; Durieux, E; Majumdar, MRD; Foka, P; Fokin, S; Ganti, MS; Garpman, S; Geurts, F; Ghosh, TK; Glasow, R; Gupta, SK; Gustafsson, H.A.; Gutbrod, HH; Hartig, M; Holker, G; Ippolitov, M; Izycki, M; Kachroo, S; Kalechofsky, H; Kamermans, R; Kampert, KH; Karadjev, K; Kolb, BW; Kumar, [No Value; Langbein, [No Value; Langheinrich, J; Lebedev, A; Lohner, H; Lokanathan, S; Manko, [No Value; Martin, M; Mittra, IS; Mookerjee, S; Naef, H; Nayak, SK; Nikolaev, S; Nystrand, J; Obenshain, FE; Oskarsson, A; Otterlund, [No Value; Peitzmann, T; Plasil, F; Purschke, M; Raniwala, S; Rao, NK; Rosselet, L; Roters, B; Rubio, JM; Saini, S; Sambyal, SS; Santo, R; Siemiarczuk, T; Siemssen, R; Sinha, BC; Slegt, S; Soderstrom, K; Solomey, N; Sorensen, SP; Stefanek, G; Steinhaeuser, P; Stenlund, E; Ster, A; Stuken, D; Trivedi, MD; Twenhoefel, C; vanEijndhoven, N; vanHeeringen, E; Vinogradov, A; Viyogi, YP; Young, GR

    Inclusive photons of low transverse momenta have been measured in 200 GeV/nucleon S-32+Au collisions at the CERN SPS. Data were taken in the WA93 experiment using a small acceptance BGO detector with longitudinal segmentation. The results are compared to WA80 measurements for the same system and

  13. High transverse momentum inclusive neutral pion production in d+Au collisions at RHIC

    NARCIS (Netherlands)

    Grebenyuk, O.|info:eu-repo/dai/nl/304848883; Mischke, A.|info:eu-repo/dai/nl/325781435; Stolpovsky, A.

    2006-01-01

    Preliminary results are presented on high pT inclusive neutral pion production in d+Au collisions at sNN = 200 GeV in the pseudo-rapidity range 0 <η <1. Photons from the decay π0 → γγ are detected in the Barrel Electromagnetic Calorimeter of the STAR experiment at RHIC. The analysis procedure is

  14. Charged-particle multiplicity at mid-rapidity in Au–Au collisions at ...

    Indian Academy of Sciences (India)

    983–986. Charged-particle multiplicity at mid-rapidity in Au–Au collisions at relativistic heavy-ion collider. D SILVERMYR, for the PHENIX Collaboration. Department of Physics, Lund University, Box 118, 22100 Lund, Sweden. Abstract. The particle density at mid-rapidity is an essential global variable for the characterization.

  15. Medium modification of jet fragmentation in Au+Au collisions at √[s(NN)]=200 GeV measured in direct photon-hadron correlations.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Al-Ta'ani, H; Alexander, J; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Bing, X; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Castera, P; Chang, B S; Chang, W C; Charvet, J-L; Chen, C-H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; Daugherity, M S; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; D'Orazio, L; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gainey, K; Gal, C; Garishvili, A; Garishvili, I; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Guo, L; Gustafsson, H-Å; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Harada, H; Hartouni, E P; Haruna, K; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Javani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, H J; Kim, K-B; Kim, S H; Kim, Y-J; Kim, Y K; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Kochenda, L; Kochetkov, V; Komatsu, Y; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Krizek, F; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, B; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Lee, M K; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Leitgab, M; Leitner, E; Lenzi, B; Lewis, B; Li, X; Liebing, P; Lim, S H; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Masumoto, S; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mohanty, A K; Moon, H J; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Nagae, T; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Nederlof, A; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Norman, B E; Nouicer, R; Novitzky, N; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, S K; Park, W J; Pate, S F; Patel, L; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Petti, R; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, R; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Samsonov, V; Sano, M; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Sen, A; Seto, R; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Soumya, M; Sourikova, I V; Sparks, N A; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, T L; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Tomita, Y; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tsuji, T; Vale, C; Valle, H; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Wolin, S; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimányi, J; Zolin, L

    2013-07-19

    The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at √[s(NN)]=200 GeV. The p(T) of the photon is an excellent approximation to the initial p(T) of the jet and the ratio z(T)=p(T)(h)/p(T)(γ) is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I(AA), the ratio of hadron yield opposite the photon in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z(T). The associated hadron yield at low z(T) is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.

  16. Single electron yields from semileptonic charm and bottom hadron decays in Au$+$Au collisions at $\\sqrt{s_{NN}}=200$ GeV

    CERN Document Server

    Adare, A; Ajitanand, N N; Akiba, Y; Akimoto, R; Alexander, J; Alfred, M; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Aschenauer, E C; Atomssa, E T; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Bathe, S; Baublis, V; Baumgart, S; Bazilevsky, A; Beaumier, M; Beckman, S; Belmont, R; Berdnikov, A; Berdnikov, Y; Black, D; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Butsyk, S; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Cronin, N; Crossette, N; Csanád, M; Csörgő, T; Dairaku, S; Danley, D; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Ding, L; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Edwards, S; Efremenko, Y V; Engelmore, T; Enokizono, A; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Gallus, P; Garg, P; Garishvili, A; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamilton, H F; Han, S Y; Hanks, J; Hasegawa, S; Haseler, T O S; Hashimoto, K; Hayano, R; Hayashi, S; He, X; Hemmick, T K; Hester, T; Hill, J C; Hollis, R S; Homma, K; Hong, B; Horaguchi, T; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Iinuma, H; Ikeda, Y; Imai, K; Imazu, Y; Imrek, J; Inaba, M; Iordanova, A; Isenhower, D; Isinhue, A; Ivanishchev, D; Jacak, B V; Javani, M; Jezghani, M; Jia, J; Jiang, X; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kamin, J; Kanda, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kawall, D; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D J; Kim, E -J; Kim, G W; Kim, M; Kim, Y -J; Kim, Y K; Kimelman, B; Kinney, E; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Komkov, B; Koster, J; Kotchetkov, D; Kotov, D; Krizek, F; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Leitgab, M; Lewis, B; Li, X; Lim, S H; Levy, L A Linden; Liu, M X; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; Maruyama, T; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Midori, J; Mignerey, A C; Milov, A; Mishra, D K; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Mohapatra, S; Montuenga, P; Moon, H J; Moon, T; Morrison, D P; Moskowitz, M; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagashima, K; Nagle, J L; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Netrakanti, P K; Nihashi, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nukariya, A; Nyanin, A S; Obayashi, H; O'Brien, E; Ogilvie, C A; Okada, K; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J S; Park, S; Park, S K; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Purschke, M L; Qu, H; Rak, J; Ramson, B J; Ravinovich, I; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Riveli, N; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rowan, Z; Rubin, J G; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, S; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seidl, R; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slunečka, M; Snowball, M; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Tieulent, R; Timilsina, A; Todoroki, T; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Voas, B; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Whitaker, S; White, A S; White, S N; Winter, D; Wolin, S; Woody, C L; Wysocki, M; Xia, B; Xue, L; Yalcin, S; Yamaguchi, Y L; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J H; Yoon, I; You, Z; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S; Zou, L

    2015-01-01

    The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy-flavor production in minimum bias Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons. Previous heavy-flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks due to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function of transverse momentum are measured in Au$+$Au collisions. We compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in $p$$+$$p$ collisions at $\\sqrt{s_{_{NN}}}=200$ GeV and find the fractions to be similar within the large uncertainties on both measurements for $p_T>4$ GeV/$c$. We use the bottom electron fr...

  17. Measurements of jet quenching with semi-inclusive hadron+jet distributions in Au+Au collisions at √{sN N}=200 GeV

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, P. M.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

    2017-08-01

    The STAR Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum hadron trigger, in central and peripheral Au +Au collisions at √{sNN}=200 GeV. Charged jets are reconstructed with the anti-kT algorithm for jet radii R between 0.2 and 0.5 and with low infrared cutoff of track constituents (pT>0.2 GeV / c ). A novel mixed-event technique is used to correct the large uncorrelated background present in heavy ion collisions. Corrected recoil jet distributions are reported at midrapidity, for charged-jet transverse momentum pT,jet chcharged energy transport out of the jet cone of 2.8 ±0.2 (stat )±1.5 (sys ) GeV /c , for 10 Au +Au collisions of 50 ±30 (sys )% of the large-angle yield in p +p collisions predicted by pythia.

  18. Estimation of the shear viscosity from 3FD simulations of Au + Au collisions at √(s{sub NN}) = 3.3-39 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu.B. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); National Research Nuclear University ' ' MEPhI' ' , (Moscow Engineering Physics Institute), Moscow (Russian Federation); Soldatov, A.A. [National Research Nuclear University ' ' MEPhI' ' , (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2016-05-15

    An effective shear viscosity in central Au+Au collisions is estimated in the range of incident energies 3.3 GeV≤√(s{sub NN})≤39 GeV. The simulations are performed within a three-fluid model employing three different equations of state with and without the deconfinement transition. In order to estimate this effective viscosity, we consider the entropy produced in the 3FD simulations as if it is generated within the conventional one-fluid viscous hydrodynamics. It is found that the effective viscosity within the different considered scenarios is very similar at the expansion stage of the collision: as a function of temperature (T) the viscosity-to-entropy ratio behaves as η/s∝1/T{sup 4}; as a function of the net-baryon density (n{sub B}), η/s∝1/s, i.e. it is mainly determined by the density dependence of the entropy density. The above dependences take place along the dynamical trajectories of Au+Au collisions. At the final stages of the expansion the η/s values are ranged from ∝0.05 at the highest considered energies to ∝.5 at the lowest ones. (orig.)

  19. Measurement of D0 Meson Production and Azimuthal Anisotropy in Au+Au Collisions at √{sNN } = 200 GeV

    Science.gov (United States)

    Xie, Guannan; STAR Collaboration

    2017-08-01

    Due to the large masses, heavy-flavor quarks are dominantly produced in initial hard scattering processes and experience the whole evolution of the medium produced in heavy-ion collisions at RHIC energies. They are also expected to thermalize slower than light-flavor quarks. Thus the measurement of heavy quark production and azimuthal anisotropy can provide important insights into the medium properties through their interactions with the medium. In these proceedings, we report measurements of D0 production and elliptic flow (v2 via topological reconstruction using STAR's recently installed Heavy Flavor Tracker (HFT). The new measurement of the nuclear modification factor (RAA) of D0 mesons in central Au+Au collisions at √{sNN } = 200 GeV confirms the strong suppression at high transverse momenta (pT) reported in the previous publication with much improved precision. We also report the measurement of elliptic flow for D0 mesons in a wide transverse momentum range in 0-80% minimum-bias Au+Au collisions. The D0 elliptic flow is finite for pT > 2 GeV / c and is systematically below that of light hadrons in the same centrality interval. Furthermore, several theoretical calculations are compared to both RAA and v2 measurements, and the charm quark diffusion coefficient is inferred to be between 2 and ∼12.

  20. Measurement of charm meson production in Au+Au collisions at √S NN =200 GEV

    Science.gov (United States)

    Quintero, Amilkar

    The study and characterization of nuclear matter under extreme conditions of temperature and pressure, and a full understanding of deconfined partonic matter, the Quark Gluon Plasma (QGP), are major goals of modern high-energy nuclear physics. Heavy quarks (charm and bottom) are formed mainly in the early stages of the collision. Open heavy flavor measurements, e.g. D0, D+/-, DS, are excellent tools to probe and study the hot and dense medium formed in heavy ion collisions. Details of their interaction with the surrounding medium can be studied through energy loss and elliptic flow measurements thus providing valuable information about the nature of the medium and its degree of thermalization. Initial indirect reconstruction studies of heavy quark particles using the electrons from heavy flavor decays, showed a large magnitude of energy loss that was inconsistent with model predictions and assumptions, at the time. Precise measurements of fully reconstructed heavy mesons would provide better understanding of the energy loss mechanisms and the properties of the formed medium. In relativistic heavy ion collisions, the relatively low abundance of heavy quarks and their short lifetimes makes them difficult to distinguish from the event vertex and the combinatorial background; therefore the need for a high precision vertex detector to reconstruct their decay particles. In 2014 a new micro vertex detector was installed in the STAR experiment at Brookhaven National Lab. The Heavy Flavor Tracker (HFT) was designed to perform direct topological reconstruction of the weak decays of heavy flavor particles. The HFT improves STAR track pointing resolution from a few millimeters to ˜30 microns for 1 GeV/c pions, allowing direct reconstruction of short lifetime particles. Although the results of the open charm meson reconstruction using the HFT improved dramatically there is still a lot of room for optimization, especially for reconstructed particles with low transverse momentum

  1. Centrality dependence of pi(+/-), K(+/-), p, and (-)p production from sqrt[s(NN)] = 130 GeV Au + Au collisions at RHIC.

    Science.gov (United States)

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2002-06-17

    Identified pi(+/-), K(+/-), p, and (-)p transverse momentum spectra at midrapidity in sqrt[s(NN)] = 130 GeV Au+Au collisions were measured by the PHENIX experiment at RHIC as a function of collision centrality. Average transverse momenta increase with the number of participating nucleons in a similar way for all particle species. Within errors, all midrapidity particle yields per participant are found to be increasing with the number of participating nucleons. There is an indication that K(+/-), p, and (-)p yields per participant increase faster than the pi(+/-) yields. In central collisions at high transverse momenta (p(T) > or =2 GeV/c), (-)p and p yields are comparable to the pi(+/-) yields.

  2. Measurement of Dielectron Invariant Mass Spectra in Au + Au Collisions at p sNN = 200GeV with HBD in PHENIX

    Science.gov (United States)

    Sun, Jiayin

    Dileptons are emitted throughout the entire space-time evolution of heavy ion collisions. Being colorless, these electromagnetic probes do not participate in the final-state strong interactions during the passage through the hot medium, and retain the information on the conditions of their creation. This characteristic renders them valuable tools for studying the properties of the Quark Gluon Plasma created during ultra-relativistic heavy ion collisions. The invariant mass spectra of dileptons contain a wealth of information on every stage of the evolution of heavy ion collisions. At low mass, dilepton spectra consist mainly of light meson decays. The medium modification of the light vector mesons gives insight on the chiral symmetry restoration in heavy ion collisions. At intermediate and high mass, there are significant contributions from charm and bottom, with a minor contribution from QGP thermal radiation. The region was utilized to measure cross sections of open charm and open bottom, as well as quarkonium suppression as demonstrated by PHENIX. An earlier PHENIX measurement of dielectron spectra in heavy ion collisions, using data taken in 2004, shows significant deviations from the hadronic decay expectations. The measurement, however, suffered from an unfavorable signal to background ratio. Random combination of electron-positron pairs from unrelated sources, mostly Dalitz decay of pi0 and external conversion of decay photon to electrons, is the main contributor to the background. Mis-identified hadrons are another major background source. To improve the situation, the Hadron Blind Detector (HBD), a windowless proximity focusing Cerenkov detector, is designed to reduce this background by identifying electron tracks from photon conversions and pi. 0 Dalitzdecays. The detector has been installed and operated in PHENIX in 2009 and 2010, where reference p+p and Au+Au data sets were successfully taken. We will present the dielectron results from the analysis of

  3. Measurements of electrons from semi-leptonic heavy flavor decays in p+p and Au+Au collisions at √{sNN } = 200 GeV at STAR

    Science.gov (United States)

    Wang, Yaping; STAR Collaboration

    2017-08-01

    In these proceedings, we present recent results on electrons from semi-leptonic decays of open heavy-flavor hadrons (eHF) with the STAR detector at the Relativistic Heavy Ion Collider. We report the updated measurements of eHF production in p+p collisions at √{ s } = 200 GeV with significantly improved precision and wider kinematic coverage than previous measurements. With this new p+p reference, we obtain the nuclear modification factor (RAA) for eHF in Au+Au collisions at √{sNN } = 200 GeV using 2010 data. The RAA shows significant suppression at high pT in most central Au+Au collisions, while the suppression reduces gradually towards more peripheral collisions. We compare eHFRAA in central Au+Au collisions to that in central U+U collisions at √{sNN } = 193 GeV and find that they are consistent within uncertainties. We also show the results of B-hadron contribution to eHF extracted from azimuthal correlations between eHF and charged hadrons in p+p collisions. Finally we report the measurements of eHF from open bottom hadron decays and discuss the prospect of measuring eHF from open bottom and charm hadron decays separately utilizing the Heavy Flavor Tracker in Au+Au collisions.

  4. Latest results of charged hadron flow measurements in CuAu collisions at RHIC-PHENIX

    Science.gov (United States)

    Nakagomi, Hiroshi

    2016-08-01

    Measurements of azimuthal anisotropic flow vn for inclusive charged hadrons and identified particles at mid rapidity in Cu+Au collisions at √sNN = 200GeV are presented. The data were recorded by the PHENIX experiment at Relativistic Heavy Ion Collider(RHIC). Directed, elliptic and triangular flow as a function of transverse momentum pT are measured with respect to event planes. The inclusive charged hadron vi shows the negative value at high pT. The v2 and v3 are compared to those in Au+Au and Cu+Cu collisions. We find the v 2 and v3 follow an empirical scaling with 1/(ɛnN1/3 part). We also compare the v2 and v3 to hydrodynamical predictions. The identified particles v2 and v3 show a mass ordering in low pT region and baryon and meson splitting in high pT region. However the identified hadron v1 only shows mass ordering in mid pT region.

  5. Production of {lambda}(1520) in p+p and Au+Au collisions with {radical}s{sub NN} = 200 GeV in the STAR experiment at RHIC; Production de {lambda}(1520) dans les collisions p+p et Au+Au a {radical}s{sub NN} = 200 GeV dans l'experience STAR au RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gaudichet, L

    2003-10-01

    Ultra-relativistic heavy ion collisions are produced in order to observe the created hot and dense matter. One major goal is to probe the existence of the Quark Gluon Plasma (QGP). The QGP would be the state of matter in which temperature and density are high enough to break the quark confinement into hadrons. For that purpose, the RHIC collider has produced p+p and Au+Au collisions at the energy of {radical}s{sub NN}= 200 GeV. This thesis work is focused on the production of {lambda}(1520) resonances in these collisions with the STAR experiment. In comparison with statistical prediction, the measured {lambda}(1520)/{lambda} show a significant lowering in ultra-relativistic heavy ion collisions. These results strongly support the decoupling of the system in two stages: a chemical freeze-out followed by a thermal freeze-out. This conclusion constitutes an important step to an understanding of the created matter in high energy heavy ion collisions. (author)

  6. Nuclear matter effects on $J/\\psi$ production in asymmetric Cu+Au collisions at $\\sqrt{s_{_{NN}}}$ = 200 GeV

    CERN Document Server

    Aidala, C; Akiba, Y; Akimoto, R; Alexander, J; Aoki, K; Apadula, N; Asano, H; Atomssa, E T; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Bai, X; Bannier, B; Barish, K N; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Beaumier, M; Belmont, R; Berdnikov, A; Berdnikov, Y; Bing, X; Black, D; Blau, D S; Bok, J; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Butsyk, S; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Christiansen, P; Chujo, T; Cianciolo, V; Cole, B A; Cronin, N; Crossette, N; Csanád, M; Csörgő, T; Datta, A; Daugherity, M S; David, G; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Ding, L; Do, J H; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; D'Orazio, L; Engelmore, T; Enokizono, A; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger,, M; Fleuret, F; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Gainey, K; Gal, C; Garg, P; Garishvili, A; Garishvili, I; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guragain, H; Haggerty, J S; Hahn, K I; Hamagaki, H; Hanks, J; Hashimoto, K; Hayano, R; He, X; Hemmick, T K; Hester, T; Hill, J C; Hollis, R S; Homma, K; Hong, B; Hoshino, T; Huang, J; Huang, S; Ichihara, T; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Iordanova, A; Isenhower, D; Isinhue, A; Ivanishchev, D; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kamin, J; Kanda, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Kawall, D; Kazantsev, A V; Key, J A; Khachatryan, V; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, C; Kim, D J; Kim, E -J; Kim, Y -J; Kim, Y K; Kistenev, E; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kofarago, M; Komkov, B; Koster, J; Kotchetkov, D; Kotov, D; Krizek, F; Kurita, K; Kurosawa, M; Kwon, Y; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, G H; Lee, J; Lee, K B; Lee, K S; Lee, S H; Leitch, M J; Leitgab, M; Lewis, B; Li, X; Lim, S H; Liu, M X; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; Maruyama, T; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Milov, A; Mishra, D K; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Morrison, D P; Moskowitz, M; Moukhanova, T V; Murakami, T; Murata, J; Nagae, T; Nagamiya, S; Nagle, J L; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Netrakanti, P K; Nihashi, M; Niida, T; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; O'Brien, E; Ogilvie, C A; Oide, H; Okada, K; Oskarsson, A; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, S; Park, S K; Pate, S F; Patel, L; Peng, J -C; Perepelitsa, D; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pisani, R P; Purschke, M L; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Riveli, N; Roach, D; Rolnick, S D; Rosati, M; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, S; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Sekiguchi, Y; Sen, A; Seto, R; Sett, P; Sharma, D; Shaver, A; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slunečka, M; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Soumya, M; Sourikova, I V; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Stone, M R; Sugitate, T; Sukhanov, A; Sun, J; Takahara, A; Taketani, A; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Timilsina, A; Todoroki, T; Tomášek, M; Torii, H; Towell, R S; Tserruya, I; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Whitaker, S; Wolin, S; Woody, C L; Wysocki, M; Yamaguchi, Y L; Yanovich, A; Yokkaichi, S; Yoon, I; You, Z; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S

    2014-01-01

    We report on $J/\\psi$ production from asymmetric Cu+Au heavy-ion collisions at $\\sqrt{s_{_{NN}}}$=200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of $J/\\psi$ yields in Cu$+$Au collisions in the Au-going direction is found to be comparable to that in Au$+$Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, $J/\\psi$ production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-$x$ gluon suppression in the larger Au nucleus. The relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.

  7. Nucleon shadowing effects in Cu + Cu and Au + Au collisions at RHIC within the HIJING code

    Science.gov (United States)

    Abdel-Waged, Khaled; Felemban, Nuha

    2018-02-01

    The centrality dependence of pseudorapidity density of charged particles ({{{d}}{N}}{{ch}}/{{d}}η ) in Cu + Cu (Au + Au) collisions at Relativistic Heavy Ion Collider energy of \\sqrt{{s}{{NN}}}=22.4, 62.4 and 200 (19.6, 62.4 and 200) GeV, is investigated within an improved HIJING code. The standard HIJING model is enhanced by a prescription for collective nucleon–nucleon (NN) interactions and more modern parton distribution functions. The collective NN-interactions are used to induce both cascade and nucleon shadowing effects. We find collective cascade broadens the pseudorapidity distributions in the tails (at | η | > {y}{beam}) above 25%–30% collision centrality to be consistent with the {{{d}}{N}}{{ch}}/{{d}}η data at \\sqrt{{s}{{NN}}} =19.6,22.4,62.4 {GeV}. The overall contribution of nucleon shadowing is shown to depress the whole shape of {{{d}}{N}}{{ch}}/{{d}}η in the primary interaction region (at | η | < {y}{beam}) for semiperipheral (20%–25%) and peripheral (≥slant 35 % {--}40 % ) Cu + Cu (Au + Au) interactions at \\sqrt{{s}{{NN}}}=200 {GeV}, in accordance with the PHOBOS data.

  8. PHENIX results on reconstructed jets in p + p and Cu + Au collisions

    Science.gov (United States)

    Timilsina, Arbin

    2016-12-01

    Measurements of jet production rates in p+p and Cu+Au collisions at √{sNN} = 200 GeV with the PHENIX detector are reported. Jets are reconstructed using the anti-kt algorithm with R = 0.2 from charged particles and electromagnetic clusters. The jet spectra are unfolded to correct for detector effects and underlying event background, and the resulting jet spectra are reported for the transverse momentum range 12 collision centrality. The results indicated that jets are suppressed by approximately a factor of two in the most central collisions.

  9. Systematic study of charged-pion and kaon femtoscopy in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}$=200 GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Alfred, M; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Hartouni, E P; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Ikeda, Y; Imai, K; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kang, J H; Kapustinsky, J; Karatsu, K; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, G W; Kim, M; Kim, S H; Kim, Y -J; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Lee, S; Lee, S H; Leitch, M J; Leite, M A L; Leitner, E; Lenzi, B; Li, X; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, D K; Mishra, M; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, T; Nakano, K; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Snowball, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stepanov, M; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J H; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhang, C; Zhou, S; Zolin, L; Zou, L

    2015-01-01

    We present a systematic study of charged pion and kaon interferometry in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}$=200 GeV. The kaon mean source radii are found to be larger than pion radii in the outward and longitudinal directions for the same transverse mass; this difference increases for more central collisions. The azimuthal-angle dependence of the radii was measured with respect to the second-order event plane and similar oscillations of the source radii were found for pions and kaons. Hydrodynamic models qualitatively describe the similar oscillations of the mean source radii for pions and kaons, but they do not fully describe the transverse-mass dependence of the oscillations.

  10. Azimuthally anisotropic emission of low-momentum direct photons in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Castera, P; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Gallus, P; Garg, P; Garishvili, A; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Guo, L; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Hartouni, E P; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Jacak, B V; Javani, M; Jezghani, M; Jia, J; Jiang, X; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, G W; Kim, H J; Kim, K -B; Kim, M; Kim, S H; Kim, Y -J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Komatsu, Y; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Krizek, F; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, B; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Lee, S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Leitgab, M; Leitner, E; Lenzi, B; Lewis, B; Li, X; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Masui, H; Masumoto, S; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, D K; Mishra, M; Mitchell, J T; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Mohapatra, S; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagashima, K; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Nederlof, A; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Sako, H; Samsonov, V; Sano, M; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Snowball, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Tsuji, T; Vale, C; Valle, H; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Wolin, S; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J H; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhang, C; Zhou, S; Zolin, L; Zou, L

    2015-01-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider has measured 2nd and 3rd order Fourier coefficients of the azimuthal distributions of direct photons emitted at midrapidity in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV for various collision centralities. Combining two different analysis techniques, results were obtained in the transverse momentum range of $0.4

  11. Particle-type dependence of azimuthal anisotropy and nuclearmodification of particle production in Au+Au collisions at sNN = 200GeV

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Badyal,S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele,S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj,S.; Bhaskar, P.; Bhati, A.K.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman,R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll,J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay,S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Ganti, M.S.; Gutierrez, T.D.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grigoriev, V.; Gronstal, S.; Drosnick, D.; Guedon, M.; Guertin, S.M.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang,S.L.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Konstantinov, A.; Kopytine,S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger,K.; Kuhn, C.; Kulikov, A.I.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.K.; et al.

    2003-06-18

    We present STAR measurements of the azimuthal anisotropy parameter v{sub 2} and the binary-collision scaled centrality ratio R{sub CP} for kaons and lambdas ({Lambda} + {bar {Lambda}}) at mid-rapidity in Au+Au collisions at {radical}s{sub NN} = 200 GeV. In combination, the v{sub 2} and R{sub CP} particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish p{sub T} {approx} 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K{sub S}{sup 0} and {Lambda} + {bar {Lambda}} v{sub 2} values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.

  12. Ratios of charged antiparticles to particles near mid-rapidity in Au+Au collisions at sqrt(s_NN) = 130 GeV

    CERN Document Server

    Back, B B; Barton, D S; Betts, R R; Bindel, R; Budzanowski, A; Busza, W; Carroll, A; Decowski, M P; García, E; George, N; Gulbrandsen, K H; Gushue, S; Halliwell, C; Heintzelman, G A; Henderson, C; Holynski, R; Hofman, D J; Holzman, B; Johnson, E; Kane, J; Katzy, J M; Khan, N A; Kucewicz, W; Kulinich, P A; Lin, W T; Manly, S L; McLeod, D; Michalowski, J; Mignerey, A C; Mülmenstädt, J; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Pernegger, H; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Rosenberg, L J; Sarin, P; Sawicki, P; Skulski, W; Steadman, S G; Stephans, G S F; Steinberg, P; Stodulski, M; Sukhanov, A; Tang, J L; Teng, R; Trzupek, A; Vale, C J; van Nieuwenhuizen, G J; Verdier, R; Wadsworth, B; Wolfs, F L H; Wosiek, B; Wozniak, K; Wuosmaa, A H; Wyslouch, B

    2001-01-01

    We have measured the ratios of antiparticles to particles for charged pions, kaons and protons near mid-rapidity in central Au+Au collisions at sqrt(s_NN) = 130 GeV. For protons, we observe pbar/p = 0.60 +/- 0.04 (stat.) +/- 0.06 (syst.) in the transverse momentum range 0.15 < p_T < 1.0 GeV/c. This leads to an estimate of the baryo-chemical potential mu_B of 45 MeV, a factor of 5-6 smaller than in central Pb+Pb collisions at sqrt(s_NN) = 17.2 GeV.

  13. Two-particle short-range correlations relative to the reaction plane in Au +Au collisions at 200 GeV at RHIC/ STAR

    Science.gov (United States)

    Yan, Haochen; STAR Collaboration

    2017-09-01

    High-energy heavy-ion collisions can create a hot and dense nuclear medium in which local domains could obtain a chirality imbalance. The chirality imbalance, together with a strong magnetic field, can induce an electric charge separation along the magnetic field direction, owing to the chiral magnetic effect (CME). The γ correlator measures the two-particle azimuthal correlations relative to the reaction plane, and provides a probe to the electric charge separation due to the CME. However, the γ correlator contains short-range correlations caused by other physics mechanisms, such as quantum effects, Coulomb interaction and resonance decays. In this poster, we decompose the γ correlator into two parts, along and across the reaction plane, respectively, and separate the contributions of particle pairs with small relative pseudorapidity (short range). The results will be presented for 200 GeV Au +Au collisions, and the physics implications on the short-range background will be discussed.

  14. Azimuthally anisotropic emission of low-momentum direct photons in Au + Au collisions at √{sN N}=200 GeV

    Science.gov (United States)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Alexander, J.; Alfred, M.; Al-Ta'Ani, H.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Danley, T. W.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hamilton, H. F.; Han, R.; Han, S. Y.; Hanks, J.; Hartouni, E. P.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jezghani, M.; Jia, J.; Jiang, X.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kanda, S.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, G. W.; Kim, H. J.; Kim, K.-B.; Kim, M.; Kim, S. H.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kochenda, L.; Komatsu, Y.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Lee, S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Leitner, E.; Lenzi, B.; Lewis, B.; Li, X.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Masumoto, S.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, D. K.; Mishra, M.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Mohapatra, S.; Montuenga, P.; Moon, H. J.; Moon, T.; Morino, Y.; Morreale, A.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagashima, K.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, J. S.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peresedov, V.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rowan, Z.; Rubin, J. G.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Sako, H.; Samsonov, V.; Sano, M.; Sano, S.; Sarsour, M.; Sato, S.; Sato, T.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, T. L.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Togawa, M.; Toia, A.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, C. L.; Towell, R.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; Valle, H.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; White, A. S.; White, S. N.; Winter, D.; Wolin, S.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoon, I.; You, Z.; Young, G. R.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhang, C.; Zhou, S.; Zolin, L.; Zou, L.; Phenix Collaboration

    2016-12-01

    The PHENIX experiment at the BNL Relativistic Heavy Ion Collider has measured second- and third-order Fourier coefficients of the azimuthal distributions of direct photons emitted at midrapidity in Au +Au collisions at √{sNN}=200 GeV for various collision centralities. Combining two different analysis techniques, results were obtained in the transverse momentum range of 0.4

  15. Anisotropic Flow in sqrt(s_NN) = 200 GeV Cu+Cu and Au+Au collisions at PHENIX

    CERN Document Server

    Masui, H

    2006-01-01

    We report the measurement of anisotropic flow at RHIC - PHENIX experiment. We present the v_4 results at sqrt(s_NN) = 200 GeV in Au+Au collision. The scaling ratio of v_4/(v_2)^2 is about 1.5 and it is found to be smaller than the prediction from simple coalescence model. The v_2 for high p_T identified particles ($\\sim$ 5 GeV/c) measured with Aerogel Cherenkov Counter are presented. We discuss the constituent quark scaling of v_2 for identified particles. We also report the first observation of v_2 for inclusive charged hadrons as well as identified hadrons at sqrt(s_NN) = 200 GeV in Cu+Cu collisions. The system size dependence of v_2 and scaling properties are discussed.

  16. Enhanced production of direct photons in Au + Au collisions at square root(S(NN)) = 200 GeV and implications for the initial temperature.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Al-Jamel, A; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bickley, A A; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chang, B S; Charvet, J-L; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Das, K; David, G; Deaton, M B; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Eyser, K O; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Forestier, B; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fung, S-Y; Fusayasu, T; Gadrat, S; Garishvili, I; Gastineau, F; Germain, M; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-A; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hagiwara, M N; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; Heuser, J M; He, X; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hur, M G; Ichihara, T; Imai, K; Inaba, M; Inoue, Y; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Kawagishi, T; Kawall, D; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kroon, P J; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y-S; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Lim, H; Liska, T; Litvinenko, A; Liu, M X; Li, X; Li, X H; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mao, Y; Masek, L; Masui, H; Matathias, F; McCain, M C; McCumber, M; McGaughey, P L; Miake, Y; Mikes, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mishra, M; Mitchell, J T; Mitrovski, M; Morreale, A; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Norman, B E; Nyanin, A S; Nystrand, J; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, H; Okada, K; Oka, M; Omiwade, O O; Oskarsson, A; Otterlund, I; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakata, H; Samsonov, V; Sato, H D; Sato, S; Sawada, S; Seele, J; Seidl, R; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Slunecka, M; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Thomas, T L; Togawa, M; Toia, A; Tojo, J; Tomásek, L; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tuli, S K; Tydesjö, H; Tyurin, N; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vertesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zimányi, J; Zolin, L

    2010-04-02

    The production of e+ e- pairs for m(e+ e-)photon internal conversions, the invariant yield of direct photons is deduced. In central Au+Au collisions, the excess of the direct photon yield over p+p is exponential in transverse momentum, with an inverse slope T=221+/-19(stat)+/-19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) approximately 300-600 MeV at times of approximately 0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at approximately 170 MeV.

  17. Phobos results on charged particle multiplicity and pseudorapidity distributions in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies

    CERN Document Server

    Alver, B; Baker, M D; Ballintijn, M; Barton, D S; Betts, R R; Bickley, A A; Bindel, R; Budzanowski, A; Busza, W; Carroll, A; Chai, Z; Chetluru, V; Decowski, M P; Garcıa, E; Gburek, T; George, N; Gulbrandsen, K; Gushue, S; Halliwell, C; Hamblen, J; Heintzelman, G A; Henderson, C; Hofman, D J; Hollis, R S; Holynski, R; Holzman, B; Iordanova, A; Johnson, E; Kane, J L; Katzy, J; Khan, N; Kucewicz, J Kotula W; Kulinich, P; Kuo, C M; Li, W; Lin, W T; Loizides, C; Manly, S; McLeod, D; Michalowski, J; Mignerey, A C; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Pernegger, H; Reed, C; Remsberg, L P; Reuter, M; Roland, C; Roland, G; Rosenberg, L; Sagerer, J; Sarin, P; Sawicki, P; Sedykh, I; Skulski, W; Smith, C E; Steadman, S G; Steinberg, P; Stephans, G S F; Stodulski, M; Sukhanov, A; Tonjes, M B; Trzupek, A; Vale, C; van Nieuwenhuizen, G J; Vaurynovich, S S; Verdier, R; Veres, G I; Wadsworth, B; Walters, P; Wenger, E; Wolfs, F L H; Wosiek, B; Wozniak, K; Wuosmaa, A H; Wyslouch, B

    2010-01-01

    Pseudorapidity distributions of charged particles emitted in $Au+Au$, $Cu+Cu$, $d+Au$, and $p+p$ collisions over a wide energy range have been measured using the PHOBOS detector at RHIC. The centrality dependence of both the charged particle distributions and the multiplicity at midrapidity were measured. Pseudorapidity distributions of charged particles emitted with $|\\eta|<5.4$, which account for between 95% and 99% of the total charged-particle emission associated with collision participants, are presented for different collision centralities. Both the midrapidity density, $dN_{ch}/d\\eta$, and the total charged-particle multiplicity, $N_{ch}$, are found to factorize into a product of independent functions of collision energy, $\\sqrt{s_{_{NN}}}$, and centrality given in terms of the number of nucleons participating in the collision, $N_{part}$. The total charged particle multiplicity, observed in these experiments and those at lower energies, assumes a linear dependence of $(\\ln s_{_{NN}})^2$ over the fu...

  18. Charged hadron multiplicity fluctuations in Au+Au and Cu+Cu collisions from sqrt(s_NN) = 22.5 to 200 GeV

    CERN Document Server

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Al-Jamel, A; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baksay, G; Baksay, L; Baldisseri, Alberto; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bickley, A A; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Büsching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Campbell, S; Chai, J S; Chand, P; Chang, B S; Chang, W C; Charvet, J L; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Constantin, P; Csanad, M; Csrgo, T; Cussonneau, J P; Dahms, T; Das, K; Dávid, G; Dek, F; Deaton, M B; Dehmelt, K; Delagrange, oa H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Devismes, A; Dietzsch, O; Dion, A; Donadelli, M; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dutta, D; Dzhordzhadze, V; Efremenko, Yu V; Egdemir, J; Ellinghaus, F; Emam, W S; Enokizono, A; Enyo, H; Espagnon, B; Esumi, S; Eyser, K O; Fields, D E; Finck, C; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Forestier, B; Fox, B D; Fraenkel, Zeev; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fung, S Y; Fusayasu, T; Gadrat, S; Garishvili, I; Gastineau, F; Germain, M; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse-Perdekamp, M; Gunji, T; Gustafsson, H; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hagiwara, M N; Hamagaki, AH; Han, R; Hansen, A G; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; Heuser, J M; He, X; Hidas, P; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holmes, M; Holzmann, W; Homma, K; Hong, B; Hoover, A; Horaguchi, T; Hornback, D; Hur, M G; Ichihara, T; Ikonnikov, V V; Imai, K; Inaba, M; Inoue, Y; Inuzuka, M; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kanou, H; Katou, K; Kawabata, T; Kawagishi, T; Kawall, D; Kazantsev, A V; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, E; Kim, G B; Kim, H J; Kim, Y S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klay, J; Klein-Bösing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Kohara, R; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Krl, A; Kravitz, a A; Kroon, P J; Kubart, J; Kuberg, C H; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Lim, H; Lika, T; Litvinenko, s A; Liu, M X; Li, X; Li, X H; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Man'ko, V I; Mao, Y; Martínez, G; Maek, L; Masui, H; Matathias, F; Matsumoto, T; McCain, M C; McCumber, M; McGaughey, P L; Miake, Y; Mike, P; Miki, K; Miller, sT E; Milov, A; Mioduszewski, S; Mishra, G C; Mishra, M; Mitchell, J T; Mitrovski, M; Mohanty, A K; Morreale, A; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Norman, B E; Nyanin, A S; Nystrand, J; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, H; Okada, K; Oka, M; Omiwade, O O; Oskarsson, A; Otterlund, I; Ouchida, M; Oyama, K; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Penev, V; Peng, J C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pierson, A; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qualls, J M; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saitô, N; Sakaguchi, T; Sakai, S; Sakata, H; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Seele, J; Seidl, R; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shevel, A; Shibata, T A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Sluneka, M; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, cS P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarjn, P; Thomas, a T L; Togawa, M; Toia, A; Tojo, J; Tomaek, L; Torii, H; Towell, R S; Tram, V-N; Tserruya, Itzhak; Tsuchimoto, Y; Tuli, S K; Tydesj, H; Tyurin, N; Uam, T J; Vale, C; Valle, H; van Hecke, o H W; Velkovska, J; Velkovsky, M; Vertesi, R; Veszprmi, V; Vinogradov, A A; Virius, M; Volkov, e M A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Wohn, F K; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zimányi, J; Zolin, L; Zong, X

    2008-01-01

    A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for non-dynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. An analysis of Negative Binomial Distribution fits to the multiplicity distributions demonstrates that the heavy ion data exhibit we...

  19. A comparative study of the Au + H{sub 2}, Au{sup +} + H{sub 2}, and Au{sup −} + H{sub 2} systems: Potential energy surfaces and dynamics of reactive collisions

    Energy Technology Data Exchange (ETDEWEB)

    Dorta-Urra, Anaís [Facultad de Ciencias Básicas y Aplicadas, Departamento de Física, Universidad Militar Nueva Granada, Bogotá DC (Colombia); Zanchet, Alexandre; Roncero, Octavio [Instituto de Física Fundamental, CSIC Serrano 123, 28006 Madrid (Spain); Aguado, Alfredo [Facultad de Ciencias, Departamento de Química-Física Aplicada, Unidad Asociada CSIC-UAM, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-04-21

    In order to study the Au{sup −} + H{sub 2} collision, a new global potential energy surface (PES) describing the ground electronic state of AuH{sub 2}{sup −} system is developed and compared with the PESs of the neutral [Zanchet et al., J. Chem. Phys. 132, 034301 (2010)] and cationic systems [Anaís et al., J. Chem. Phys. 135, 091102 (2011)]. We found that Au{sup −} − H{sub 2} presents a H-Au-H insertion minimum attributed to the stabilization of the LUMO 3b{sub 2} orbital, which can be considered as the preamble of the chemisorption well appearing in larger gold clusters. While the LUMO orbital is stabilized, the HOMO 6a{sub 1} is destabilized, creating a barrier at the geometry where the energy orbitals’ curves are crossing. In the anion, this HOMO is doubly occupied, while in the neutral system is half-filled and completely empty in the cation, explaining the gradual disappearance of the well and the barrier as the number of electrons decreases. The cation presents a well in the entrance channel partially explained by electrostatic interactions. The three systems’ reactions are highly endothermic, by 1.66, 2.79, and 3.23 eV for AuH, AuH{sup +}, and AuH{sup −} products, respectively. The reaction dynamics is studied using quasi-classical trajectory method for the three systems. The one corresponding to the anionic system is new in this work. Collision energies between 1.00 and 8.00 eV, measured for the cation, are in good agreement with the simulated cross section for the AuH{sup +}. It was also found that the total fragmentation, in three atoms, competes becoming dominant at sufficiently high energy. Here, we study the competition between the two different reaction pathways for the anionic, cationic, and neutral species, explaining the differences using a simple model based on the topology of the potential energy surfaces.

  20. Kaon production and kaon to pion ratio in Au+Au collisions at $\\sqrt {s_{NN}} = 130 GeV

    CERN Document Server

    Adler, C; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Deng, W S; Derevshchikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Filimonov, K; Finch, E; Fisyak, Yu; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Krämer, M; Kravtsov, P; Krüger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Le Vine, M J; Lebedev, A; Lednicky, R; Leontiev, V M; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Lo Curto, G; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnik, Yu M; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevozchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E V; Prindle, D; Pruneau, C A; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schröder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D M; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimansky, S S; Shvetcov, V S; Skoro, G P; Smirnov, N; Snellings, R; Sørensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Struck, C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; Van der Molen, A M; Vasilevski, I M; Vasilev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevsky, Yu V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N; De Moura, M M; Szanto de Toledo, A; De la Barca-Sanchez, M C; 10.1016/j.physletb.2004.06.044

    2004-01-01

    Midrapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at square root s/sub NN/=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudorapidity density. The charged kaon to pion ratios are K/sup +// pi /sup -/=0.161+or-0.002(stat)+or-0.024(syst) and K/sup -// pi /sup -/=0.146+or-0.002(stat)+or-0.022(syst) for the most central collisions. The K/sup +// pi /sup -/ ratio is lower than the same ratio observed at the SPS while the K/sup -// pi /sup -/ is higher than the SPS result. The ratios are enhanced by about 50% relative to p+p and p+p collision data at similar energies.

  1. Measurement of the midrapidity transverse energy distribution from square root of [(s)NN] = 130 GeV Au + Au collisions at RHIC.

    Science.gov (United States)

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, D; Kochetkov, V; Koehler, D; Kohama, T; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2001-07-30

    The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that / remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at square root[s(NN)] = 130 GeV is at least epsilon(Bj) = 4.6 GeV/fm(3), which is a factor of 1.6 larger than found at sqrt[s(NN)] = 17.2 GeV ( Pb+Pb at CERN).

  2. In-medium reduction of the \\eta' mass in \\sqrt{s_NN} = 200 GeV Au+Au collisions

    CERN Document Server

    Vertesi, Robert; Sziklai, Janos

    2011-01-01

    A reduction of the mass of the \\eta'(958) meson may indicate the restoration of the UA(1) symmetry in a hot and dense hadronic matter, corresponding to the return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a combined PHENIX and STAR data set on the intercept parameter of the two-pion Bose-Einstein correlation functions, as measuremed in \\sqrt{s_NN} = 200 GeV Au+Au collisions at RHIC. To describe this combined PHENIX and STAR dataset, an in-medium \\eta' mass reduction of at least 200 MeV is needed, at the 99.9 % confidence level in a broad model class of resonance multiplicities. Energy, system size and centrality dependence of the observed effect is also discussed.

  3. Measurements of identified particles at intermediate transverse momentum in the STAR experiment from Au+Au collisions at sqrt{s_{NN}}=200 GeV

    CERN Document Server

    Adams, John; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Badyal, S.K.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Bezverkhny, B.I.; Bharadwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, C.O.; Blyth, S.L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sancez, M.; Castillo, J.; Catu, O.; Cebra, D.A.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, J.H.; Chen, Y.; Cheng, J.; Cherney, Michael G.; Chikanian, A.; Choi, H.A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fornazier, K.S.F.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Gans, J.; Ganti, M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Gorbunov, Y.G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guo, Y.; Gupta, A.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs, P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein, S.R.; Koetke, D.D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K.L.; Kramer, M.; Kravtsov, P.; Kravtsov, V.I.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.; Kuznetsov, A.A.; Lamont, M.A.C.; Landgraf, J.M.; Lange, S.; LaPointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.H.; Lehocka, S.; LeVine, Micheal J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lindenbaum, S.J.; Lisa, M.A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W.J.; Long, H.; Longacre, R.S.; Lopez-Noriega, M.; Love, W.A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G.L.; Ma, J.G.; Ma, Y.G.; Magestro, D.; Mahajan, S.; Mahapatra, D.P.; Majka, R.; Mangotra, L.K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H.S.; Matulenko, Yu.A.; McClain, C.J.; McShane, T.S.; Melnick, Yu.; Meschanin, A.; Miller, M.L.; Milos, M.; Minaev, N.G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D.K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C.F.; Morozov, D.A.; Munhoz, M.G.; Nandi, B.K.; Nayak, S.K.; Nayak, T.K.; Nelson, J.M.; Netrakanti, P.K.; Nikitin, V.A.; Nogach, L.V.; Nurushev, S.B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pal, S.K.; Panebratsev, Y.; Panitkin, S.Y.; Pavlinov, A.I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Petrov, V.A.; Phatak, S.C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A.M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B.V.K.S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R.L.; Razin, S.V.; Reinnarth, J.; Relyea, D.; Retiere, F.; Ridiger, A.; Ritter, H.G.; Roberts, J.B.; Rogachevskiy, O.V.; Romero, J.L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M.J.; Sahoo, R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarsour, M.; Savin, Igor A.; Sazhin, P.S.; Schambach, J.; Scharenberg, R.P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W.Q.; Shimanskiy, S.S.; Sichtermann, E; Simon, F.; Singaraju, R.N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H.M.; Srivastava, B.; Stadnik, A.; Stanislaus, T.D.S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A.A.P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T.J.M.; Szanto de Toledo, A.; Tai, A.; Takahashi, J.; Tang, A.H.; Tarnowsky, T.; Thein, D.; Thomas, J.H.; Timmins, A.R.; Timoshenko, S.; Tokarev, M.; Trainor, T.A.; Trentalange, S.; Tribble, R.E.; Tsai, O.D.; Ulery, J.; Ullrich, T.; Underwood, David G.; Van Buren, G.; van der Kolk, N.; van Leeuwen, M.; Vander Molen, A.M.; Varma, R.; Vasilevski, I.M.; Vasiliev, A.N.; Vernet, R.; Vigdor, S.E.; Viyogi, Y.P.; Vokal, S.; Voloshin, S.A.; Waggoner, W.T.; Wang, F.; Wang, G.; Wang, J.S.; Wang, X.L.; Wang, Y.; Watson, J.W.; Webb, J.C.; Westfall, G.D.; Wetzler, A.; Whitten, C., Jr.; Wieman, H.; Wissink, S.W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Q.H.; Xu, Z.; Yepes, P.; Yoo, I.K.; Yurevich, V.I.; Zborovsky, I.; Zhan, W.; Zhang, H.; Zhang, W.M.; Zhang, Y.; Zhang, Z.P.; Zhao, Y.; Zhong, C.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A.N.; Zuo, J.X.; Braem, A.; Davenport, M.; De Cataldo, G.; Di Bari, D.; Di Mauro, A.; Kunde, G.J.; Martinengo, P.; Nappi, E.; Paic, G.; Posa, E.; Piuz, F.; Schyns, E.

    2006-01-01

    Data for Au+Au collisions at sqrt{s_{NN}}=200 GeV are analyzed to determine the ratios of identified hadrons ($\\pi$, $K$, $p$, $\\Lambda$) as functions of collision centrality and transverse momentum ($p_T$). We find that ratios of anti-baryon to baryon yields are independent of $p_T$ up to 5 GeV/c, a result inconsistent with results of theoretical pQCD calculations that predict a decrease due to a stronger contribution from valence quark scattering. For both strange and non-strange species, strong baryon enhancements relative to meson yields are observed as a function of collision centrality in the intermediate $p_T$ region, leading to $p/\\pi$ and $\\Lambda$/K ratios greater than unity. The increased $p_T$ range offered by the $\\Lambda$/K$^{0}_{S}$ ratio allows a test of the applicability of various models developed for the intermediate $p_{T}$ region. The physics implications of these measurements are discussed with regard to different theoretical models.

  4. Baryon-strangeness correlations in Au+Au collisions at √{sNN}=7.7 -200 GeV from the UrQMD model

    Science.gov (United States)

    Yang, Zhenzhen; Luo, Xiaofeng; Mohanty, Bedangadas

    2017-01-01

    Fluctuations and correlations of conserved charges are sensitive observables for studying the QCD phase transition and critical point in high-energy heavy-ion collisions. We have studied the centrality and energy dependence of mixed cumulants (up to fourth order) between net baryon and net strangeness in Au +Au collisions at √{sNN}=7.7 , 11.5, 19.6, 27, 39, 62.4, and 200 GeV from the ultrarelativistic quantum molecular dynamics (UrQMD) model. To compare with other theoretical calculations, we normalize these mixed cumulants by various order cumulants of net-strangeness distributions. We found that the results obtained from UrQMD calculations are comparable with the results from lattice QCD at low temperature and hadron resonance gas model. The ratios of mixed cumulants (R11B S,R13B S,R22B S,R31B S ) from UrQMD calculations show weak centrality dependence. However, the mixed-cumulant ratios R11B S and R31B S show strong increase at low energy, while the R13B S and R22B S are similar at different energies. Furthermore, we have also studied the correlations between different hadron species and their contributions to the net-baryon and net-strangeness correlations. These model studies can provide baselines for searching for the signals of QCD phase transition and critical point in heavy-ion collisions.

  5. Collision-induced dissociation of monolayer protected clusters Au144 and Au130 in an electrospray time-of-flight mass spectrometer.

    Science.gov (United States)

    Black, David M; Bhattarai, Nabraj; Whetten, Robert L; Bach, Stephan B H

    2014-11-13

    Gas-phase reactions of larger gold clusters are poorly known because generation of the intact parent species for mass spectrometric analysis remains quite challenging. Herein we report in-source collision-induced dissociation (CID) results for the monolayer protected clusters (MPCs) Au144(SR)60 and Au130(SR)50, where R- = PhCH2CH2-, in a Bruker micrOTOF time-of-flight mass spectrometer. A sample mixture of the two clusters was introduced into the mass spectrometer by positive mode electrospray ionization. Standard source conditions were used to acquire a reference mass spectrum, exhibiting negligible fragmentation, and then the capillary-skimmer potential difference was increased to induce in-source CID within this low-pressure region (∼4 mbar). Remarkably, distinctive fragmentation patterns are observed for each MPC[3+] parent ion. An assignment of all the major dissociation products (ions and neutrals) is deduced and interpreted by using the distinguishing characteristics in the standard structure-models for the respective MPCs. Also, we propose a ring-forming elimination mechanism to explain R-H neutral loss, as separate from the channels leading to RS-SR or (AuSR)4 neutrals.

  6. Neutral meson production in p-Be and p-Au collisions at 450 GeV beam energy

    NARCIS (Netherlands)

    Agakichiev, G; Appenheimer, M; Averbeck, R; Ballester, F; Baur, R; Brenschede, A; Diaz, J; Drees, A; Faschingbauer, U; Ferrero, JL; Fraenkel, Z; Franke, M; Fuchs, C; Gatti, E; Glassel, P; Gunzel, T; de los Hero, CP; Hess, F.; Holzmann, R; Irmscher, D; Jacob, C; Kuhn, W; Lenkeit, B; Löhner, H.; Marin, A; Marques, FM; Martinez, G; Metag, [No Value; Notheisen, M; Novotny, R; Olsen, LH; Schon, A; Schukraft, J; Ostendorf, R.; Panebrattsev, Y; Pfeiffer, A; Ravinovich, [No Value; Rehak, P; Sampietro, M; Schutz, Y; Shimansky, S; Shor, A; Simon, RS; Specht, HJ; Steiner, [No Value; Tapprogge, S; Tel-Zur, G; Tserruya, [No Value; Ullrich, T; Wilschut, H.; Wurm, JP; Yurevich, [No Value

    In a joint experiment the TAPS and CERES collaborations have studied the production of the neutral mesons pi degrees; eta and omega in 450 GeV p-Be and p-Au collisions at the CERN SPS. The mesons were identified by their pi degrees --> gamma gamma, eta --> gamma gamma, and omega --> pi degrees gamma

  7. Heavy flavor studies at forward and backward rapidities in Cu+Au collisions with PHENIX detector

    Science.gov (United States)

    da Silva, Cesar; Phenix Collaboration

    2016-09-01

    Asymmetric Cu+Au collisions at √{sNN}=200 GeV performed at RHIC in 2012 open an opportunity to study particle yields in the presence of different mixtures of initial and final state nuclear effects by using probes measured from negative to positive rapidity regions. Heavy flavor yields may be affected by initial state effects on gluons and energy loss in the final state hot medium. The 2012 run was the first where the Forward Vertex Detector (FVTX) was operating. This detector allows the identification of D and B mesons from displaced vertex measurements. Results on B-meson nuclear modification through its J/ ψ decay channel will be presented along with the status of the analysis of semi-leptonic decays of charm and bottom yields.

  8. d + Au hadron correlation measurements at PHENIX

    Energy Technology Data Exchange (ETDEWEB)

    Sickles, Anne M., E-mail: anne@bnl.gov

    2014-06-15

    In these proceedings, we discuss recent results from d + Au collisions in PHENIX ridge related measurements and their possible hydrodynamic origin. We present the v{sub 2} at midrapidity and measurements of the pseudorapidity dependence of the ridge, distinguishing between the d-going and Au-going directions. We investigate the possible geometrical origin by comparing v{sub 2} in d + Au to that in p + Pb, Au + Au and Pb + Pb collisions. Future plans to clarify the role of geometry in small collision systems at RHIC are discussed.

  9. First results on electromagnetic radiation from Au+Au collisions at E{sub beam}=1.23 GeV/u in HADES

    Energy Technology Data Exchange (ETDEWEB)

    Harabasz, Szymon [TU Darmstadt (Germany); Collaboration: HADES-Collaboration

    2015-07-01

    Investigations of heavy-ion collisions at low beam energies do not only reveal properties of vector mesons and baryonic resonances in hot/dense hadronic matter, but they also give access to the thermodynamics of QCD in the low T and high μ{sub B} region of the phase diagram. Electromagnetic radiation emitted from such collisions provides a unique chance to study these issues in the laboratory. As photons and leptons are not subject to the strong force, they are able to deliver nearly undisturbed information on the processes in which they were produced. The High Acceptance Di-Electron Spectrometer installed at GSI has been used since many years to take these opportunities and study a wide range of colliding systems from NN and πN through NA to AA, including the Au+Au at E{sub beam}=1.23 GeV/u run from April-May 2012. Here, according to the non-linear scaling ∝ A{sup 1.4}{sub part} extracted from the former C+C and Ar+KCl results, much stronger in-medium radiation is expected. In the current contribution, very non-trivial questions of e{sup +}e{sup -} identification, rejection of the strong contribution of γ-conversion and a proper treatment of combinatorics in such a background-dominated system will be addressed. A discussion of the obtained results on dilepton spectra then follows.

  10. Directed flow of identified particles in Au+Au collisions at √[SNN]=200  GeV at RHIC.

    Science.gov (United States)

    Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Alford, J; Anderson, B D; Anson, C D; Arkhipkin, D; Averichev, G S; Balewski, J; Banerjee, A; Barnovska, Z; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chung, P; Chwastowski, J; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Cui, X; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derradi de Souza, R; Dhamija, S; Didenko, L; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Elnimr, M; Engelage, J; Eppley, G; Eun, L; Evdokimov, O; Fatemi, R; Fedorisin, J; Fersch, R G; Filip, P; Finch, E; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Geurts, F; Gliske, S; Gorbunov, Y N; Grebenyuk, O G; Grosnick, D; Gupta, S; Guryn, W; Haag, B; Hajkova, O; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huck, P; Humanic, T J; Huo, L; Igo, G; Jacobs, W W; Jena, C; Joseph, J; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Kizka, V; Klein, S R; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kravtsov, P; Krueger, K; Kumar, L; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, L; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lima, L M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Longacre, R S; Lu, Y; Luo, X; Luszczak, A; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Mioduszewski, S; Mitrovski, M K; Mohammed, Y; Mohanty, B; Morozov, B; Munhoz, M G; Mustafa, M K; Naglis, M; Nandi, B K; Nasim, Md; Nayak, T K; Nogach, L V; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Oliveira, R A N; Olson, D; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Plyku, D; Poljak, N; Porter, J; Poskanzer, A M; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ruan, L; Rusnak, J; Sahoo, N R; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shao, M; Sharma, B; Sharma, M; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, N; Solanki, D; Sorensen, P; deSouza, U G; Spinka, H M; Srivastava, B; Stanislaus, T D S; Steadman, S G; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Tlusty, D; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Witzke, W; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yang, Y; Yepes, P; Yi, Y; Yip, K; Yoo, I-K; Zawisza, M; Zbroszczyk, H; Zhang, J B; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y

    2012-05-18

    STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

  11. Identified particle production, azimuthal anisotropy, and interferometry measurements in Au+Au collisions at sqrt sNN = 9.2 GeV

    Energy Technology Data Exchange (ETDEWEB)

    STAR Collaboration; Abelev, Betty

    2010-07-05

    We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au+Au collisions below the nominal injection energy at the Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance STAR detector at {radical}s{sub NN} = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density (dN/dy) in rapidity (y), average transverse momentum (), particle ratios, elliptic flow, and HBT radii are consistent with the corresponding results at similar {radical}s{sub NN} from fixed target experiments. Directed flow measurements are presented for both midrapidity and forward rapidity regions. Furthermore the collision centrality dependence of identified particle dN/dy, , and particle ratios are discussed. These results also demonstrate that the capabilities of the STAR detector, although optimized for {radical}s{sub NN} = 200 GeV, are suitable for the proposed QCD critical point search and exploration of the QCD phase diagram at RHIC.

  12. Measurement of higher cumulants of net-charge multiplicity distributions in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=7.7-200$ GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Al-Ta'ani, H; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Black, D; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Castera, P; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Cronin, N; Crossette, N; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; Daugherity, M S; David, G; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Garg, P; Garishvili, A; Garishvili, I; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guo, L; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Hartouni, E P; Hashimoto, K; Haslum, E; Hayano, R; Hayashi, S; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Iinuma, H; Ikeda, Y; Imai, K; Imazu, Y; Imrek, J; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Isinhue, A; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Jacak, B V; Javani, M; Jia, J; Jiang, X; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, H J; Kim, K -B; Kim, S H; Kim, Y -J; Kim, Y K; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Klatsky, J; Kleinjan, D; Kline, P; Kochenda, L; Komatsu, Y; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Krizek, F; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, B; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Leitgab, M; Leitner, E; Lenzi, B; Lewis, B; Li, X; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Maruyama, T; Masui, H; Masumoto, S; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Midori, J; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, D K; Mishra, M; Mitchell, J T; Miyachi, Y; Miyasaka, S; Mohanty, A K; Mohapatra, S; Moon, H J; Morino, Y; Morreale, A; Morrison, D P; Moskowitz, M; Motschwiller, S; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Nederlof, A; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nouicer, R; Novitzky, N; Nukariya, A; Nyanin, A S; Obayashi, H; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Peresedov, V; Peressounko, D Yu; Petti, R; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Riveli, N; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Sako, H; Samsonov, V; Sano, M; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Sen, A; Seto, R; Sett, P; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slunečka, M; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sukhanov, A; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, T L; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Tsuji, T; Vale, C; Valle, H; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Voas, B; Vossen, A; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; Whitaker, S; White, S N; Winter, D; Wolin, S; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhang, C; Zhou, S; Zolin, L

    2015-01-01

    We report the measurement of cumulants ($C_n, n=1\\ldots4$) of the net-charge distributions measured within pseudorapidity ($|\\eta|<0.35$) in Au$+$Au collisions at $\\sqrt{s_{_{NN}}}=7.7-200$ GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g. $C_1/C_2$, $C_3/C_1$) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of $C_1/C_2 = \\mu/\\sigma^2$ and $C_3/C_1 = S\\sigma^3/\\mu$ can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperat...

  13. Transverse Velocity Scaling in Au+Au Fragmentation

    OpenAIRE

    Lukasik, J.; Hudan, S.; Lavaud, F.; Turzo, K.; Auger, G.; Bacri, Ch.O.; Begemann-Blaich, M.L.; Bellaize, N.; Bittiger, R.; Bocage, F.; Borderie, B.; Buchet, P.; R. Bougault(LPCC); Bouriquet, B.; Charvet, J. L.

    2002-01-01

    Invariant transverse-velocity spectra of intermediate-mass fragments were measured with the 4-pi multi-detector system INDRA for collisions of Au on Au at incident energies between 40 and 150 MeV per nucleon. Their scaling properties as a function of incident energy and atomic number Z are used to distinguish and characterize the emissions in (i) peripheral collisions at the projectile and target rapidities, and in (ii) central and (iii) peripheral collisions near mid-rapidity. The importance...

  14. The reconstructed final state of Au + Au collisions from PHENIX and STAR data at sq root s = 130 AGeV - indication for quark deconfinement at RHIC

    CERN Document Server

    Csoergoe, T

    2003-01-01

    The final state of Au+Au collisions at sq root s = 130 AGeV at RHIC has been reconstructed within the framework of the Buda-Lund hydrodynamical model, by performing a simultaneous fit to final data on two-particle Bose-Einstein correlations of the STAR and PHENIX Collaborations, and final identified single-particle spectra as measured by the PHENIX Collaboration. The results indicate a strongly three dimensional expansion, with a four-velocity field that is almost a spherically symmetric Hubble flow. Large transverse geometrical source sizes, R sub G = 9.8 +- 1.2 fm, relatively short mean freeze-out time, tau sub 0 = 6.1 +- 0.3 fm/c and a short duration of particle emission, DELTA tau = 0.02 +- 1.5 fm/c was found. Most strikingly, an indication for a hot central part of the hydrodynamically evolving core was found, characterized by a central temperature of T sub 0 = 202 +- 13 MeV that is close to (or even above) the deconfinement temperature of the quark-hadron phase transition. The best fit indicates a cold ...

  15. Measurement of J/ψ production in Au+Au collisions at √{sNN } = 200 GeV by the STAR experiment

    Science.gov (United States)

    Huang, Xinjie; STAR Collaboration

    2017-08-01

    We present the first measurements of the J / ψ nuclear modification factor (RAA) and elliptic flow (v2) via the dimuon channel by the STAR experiment using the recently installed Muon Telescope Detector. These measurements are based on the data taken in the RHIC 2014 run. A clear suppression of J / ψ yields at high transverse momenta (pT) is observed in central Au+Au collisions at √{sNN } = 200 GeV, which indicates that dissociation is in effect since contributions from other sources, such as the regeneration and cold nuclear matter effects, are very small in this kinematic range. Transport models including both dissociation and regeneration effects can qualitatively describe the measured J / ψRAA in different centrality intervals. Furthermore, the measured J / ψv2 is consistent with zero within uncertainties for pT above 2 GeV/c, which disfavors the scenario that J / ψ's in this kinematic region are dominantly from the coalescence of fully thermalized charm quarks.

  16. Exclusive study of Ni+Ni and Ni+Au central collisions: phase coexistence and spinodal decomposition; Etude exclusive des collisions centrales Ni+Ni et Ni+Au: coexistence de phase et decomposition spinodale

    Energy Technology Data Exchange (ETDEWEB)

    Guiot, B

    2002-12-01

    The INDRA multidetector allowed us to study the Ni+Ni collisions at 32A MeV and the Ni+Au collisions at 52,4 MeV. Central collisions leading to 'quasi-fused' systems were isolated using multidimensional analysis techniques: the Discriminant Analysis and the Principal Component Analysis. Comparison with a statistical model shows that the selected events are compatible with thermodynamical equilibrium. The average thermal excitation energy is 5A MeV for both systems. Calculations of heat capacities show that the deexcitation of the hot sources are akin to a liquid-gas phase transition of nuclear matter. Indeed heat capacities exhibit a negative branch as expected for a phase transition of a finite system. The dynamics of this phase transition has been investigated by applying the charge correlation method. An enhanced production of events with equal-sized fragments has been evidenced for Ni+Au at 52A MeV. No signal was found for Ni+Ni at 32A MeV. Finally this method was improved by taking into account the total charge conservation. The signal is seen more clearly for Ni+Au at 52A MeV, but is ambiguous for Ni+Ni at 32A MeV. The path followed in the state diagram, or the involved time scales, seem to be different for these systems. (authors)

  17. PHENIX results on anisotropic flow in d+Au collisions from 19.6 to 200 GeV

    Science.gov (United States)

    Morrow, Sylvia; Phenix Collaboration

    2017-09-01

    Results on elliptic flow in p+p and p/d/3He+A have raised the question of how small a system can be while still exhibiting collective behavior. In 2016, RHIC operations included d+Au collisions at 200, 62.4, 39, and 19.6 GeV. In this talk we present results on elliptic and triangular flow at midrapidity as a function of transverse momentum and event multiplicity in d+Au collisions at various energies. We compare these results with several theoretical predictions in scenarios including pre-equilibrium flow, hydrodynamic flow, partonic scattering, and purely hadronic scattering in order to assess the role of each stage in the system evolution for producing collective effects in small systems.

  18. Results from PHENIX on Deuteron and Anti-Deuteron Production in Au+Au Collisions at RHIC

    OpenAIRE

    Nystrand, Joakim; Collaboration, for the PHENIX

    2004-01-01

    Results from the PHENIX Collaboration on the production of deuterons and anti-deuterons in collisions between gold nuclei at a nucleon-nucleon center-of-mass energy of sqrt(s) = 200 GeV are presented.

  19. Energy dependence of pi, p and pbar transverse momentum spectra for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, H

    2007-03-26

    We study the energy dependence of the transverse momentum (pT) spectra for charged pions, protons and anti-protons for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV. Data are presented at mid-rapidity (lbar y rbar< 0.5) for 0.2< pT< 12 GeV/c. In the intermediate pT region (2< pT< 6 GeV/c), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher pT (pT> 7 GeV/c) the modification is similar for both energies. The p/pi+ and pbar/pi- ratios for central collisions at sqrt sNN = 62.4 GeV peak at pT _~;; 2 GeV/c. In the pT range where recombination is expected to dominate, the p/pi+ ratios at 62.4 GeV are larger than at 200 GeV, while the pbar/pi- ratios are smaller. For pT> 2 GeV/c, the pbar/pi- ratios at the two beam energies are independent of pT and centrality indicating that the dependence of the pbar/pi- ratio on pT does not change between 62.4 and 200 GeV. These findings challenge various models incorporating jet quenching and/or constituent quark coalescence.

  20. Production of neutral pions Pb+Au collisions at 158 AGeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Soualah, Rachik

    2009-06-24

    The direct photons are a particularly useful probe to search for an evidence of the Quark-Gluon Plasma formation in ultra-relativistic heavy-ion collisions. Direct photons can be extracted experimentally by measuring the large background from {pi}{sup 0} and {eta} meson decays. This thesis work represents the production of the neutral pion mesons measured with the CERES/NA45 experiment at the top SPS energy in 158 AGeV/c Pb-Au collisions. The {pi}{sup 0} {yields} {gamma}{gamma} (98.8%) is the decay channel used in the reconstruction scheme. The {pi}{sup 0} measurement is based on the data taken in the year 2000. The CERES experiment can measure the photons that convert shortly before the TPC by measuring the e{sup +}e{sup -} pairs in the TPC. The RICH2 mirror is the main converter used for this analysis. The presented analysis method describes in more details the selection of the e{sup +} and e{sup -} tracks using only the TPC information to reconstruct the converted photon. A Secondary vertex technique was developed and used to select the photons converted in the RICH2 mirror area. The extraction of the {pi}{sup 0} needs a careful study of the combinatorial background determined using the mixed event technique. The obtained invariant mass distribution of the two photons defined well the {pi}{sup 0} peak. The neutral pion transverse spectra compared to phenomenological models and other experiments validate our analysis method. (orig.)

  1. $\\phi$ meson production in $d$$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Alfred, M; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Asano, H; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Caringi, A; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; del Valle, Z Conesa; Connors, M; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Grim, G; Perdekamp, M Grosse; Gunji, T; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Ikeda, Y; Imai, K; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Issah, M; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kamin, J; Kanda, S; Kang, J H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D J; Kim, E -J; Kim, G W; Kim, M; Kim, Y -J; Kimelman, B; Kinney, E; Kiss, Á; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotov, D; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, S; Lee, S H; Leitch, M J; Leite, M A L; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Miki, K; Milov, A; Mishra, D K; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Qu, H; Rak, J; Ramson, B J; Ravinovich, I; Read, K F; Rembeczki, S; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rowan, Z; Rubin, J G; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Snowball, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stenlund, E; Stepanov, M; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Themann, H; Thomas, D; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J H; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S; Zou, L

    2015-01-01

    The PHENIX experiment has measured $\\phi$ meson production in $d$$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV using the dimuon and dielectron decay channels. The $\\phi$ meson is measured in the forward (backward) $d$-going (Au-going) direction, $1.2Au-going direction, while suppression is seen in the $d$-going direction, and no modification is observed at midrapidity relative to the yield in $p$$+$$p$ collisions scaled by the number of binary collisions. Similar behavior was previously observed for inclusive charged hadrons and open heavy flavor indicating similar cold-nuclear-matter effects.

  2. Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at sNN=19.6 and 200 GeV

    Directory of Open Access Journals (Sweden)

    L. Adamczyk

    2015-11-01

    Full Text Available The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee|<1 in minimum-bias Au+Au collisions at sNN=19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee<1.1 GeV/c2. The integrated dielectron excess yield at sNN=19.6 GeV for 0.4collisions at sNN=17.3 GeV. For sNN=200 GeV, the normalized excess yield in central collisions is higher than that at sNN=17.3 GeV and increases from peripheral to central collisions. These measurements indicate that the lifetime of the hot, dense medium created in central Au+Au collisions at sNN=200 GeV is longer than those in peripheral collisions and at lower energies.

  3. PROTON - LAMBDA CORRELATIONS IN AU-AU COLLISIONS AT SQUARE ROOT NN = 200 GEV FROM THE STAR EXPERIMENT.

    Energy Technology Data Exchange (ETDEWEB)

    RENAULT,G.; (THE STAR COLLABORATION)

    2004-03-15

    The space-time evolution of the source of particles formed in the collision of nuclei can be studied through particle correlations. The STAR experiment is dedicated to study ultra-relativistic heavy ions collisions and allows to measure non-identical strange particle correlations. The source size can be extracted by studying p - {Lambda}, {bar p} - {bar {Lambda}}, {bar p} - {Lambda} and p - {bar {Lambda}} correlation functions. Strong interaction potential has been studied for these systems using an analytical model. Final State Interaction (FSI) parameters have been determined and has shown a significant annihilation process present in {bar p} - {Lambda} and p - {bar {Lambda}} systems not present in p - {Lambda} and {bar p} - {bar {Lambda}}.

  4. Nuclear fragmentation in central collisions: Ni + Au from 32 to 90 A*MeV; Fragmentation dans les collisions centrales du systeme Ni + Au de 32 a 90 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Bellaize, N

    2000-11-03

    Heavy ion collisions are one of tools for studying nuclear system far away from its equilibrium state. This work concerns the most violent collisions in the Ni + Au system for incident energies ranging from 32 up to 90 AMeV. These events were detected with the multidetector INDRA and selected by the Principal Component Analysis (multidimensional analysis). This method classifies the events according their detection features and their degree of dissipation. We observed two deexcitation mechanisms: a fusion/fission - evaporation process and a multifragmentation process. Those two coexist from 32 to 52 AMeV whereas only one subsists at 90 AMeV. For those two mechanisms, an component was observed which seems to be linked to the initial phase of the reaction. The energy fluctuations of this component leads to variations in the energy deposit which determines the deexcitation of the system. The experimental multifragmentation data of the Ni + Au system (52 and 90 AMeV) were compared to the predictions of a statistical model and to the experimental data of the system Xe + Sn at 50 AMeV (also detected with INDRA). These comparisons show the lack of collective radial energy for fragments (Z{>=}10) in the Ni + Au system, and show that the degree of multifragmentation depends of the thermal excitation energy. Mean kinetic energies of particles and lights fragments (Z{>=}10) are larger in the Ni + Au system than the Xe + Sn system. This observation shows that these particles are more sensitive to the entrance channel for an asymmetric system than for a symmetric system (for the same number of nucleons). (author)

  5. Neutral Kaon Interferometry in Au+Au collisions at sqrt(s_NN) =200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2006-08-05

    We present the first statistically meaningful results fromtwo-K0s interferometry in heavy-ion collisions. A model that takes theeffect of the strong interaction into account has been used to fit themeasured correlation function. The effects of single and coupled channelwere explored. At the mean transverse mass m_T = 1.07 GeV, we obtain thevalues R = 4.09 +- 0.46 (stat.) +- 0.31 (sys) fm and lambda = 0.92 +-0.23 (stat) +- 0.13 (sys), where R and lambda are the invariant radiusand chaoticity parameters respectively. The results are qualitativelyconsistent with m_T systematics established with pions in a scenariocharacterized by a strong collective flow.

  6. Limits on the production of direct photons in 200 A GeV$^{32}$S + Au collisions

    CERN Document Server

    Albrecht, R; Awes, T C; Barlag, C; Berger, F; Bloomer, M A; Blume, C; Bock, D L; Böck, R K; Bohne, E M; Bucher, D; Claesson, G; Claussen, A; Clewing, G; Debbe, R; Dragon, L; Dubovik, Yu; Eklund, A; Fokin, S L; Franz, A; Garpman, S I A; Glasow, R; Gustafsson, Hans Åke; Gutbrod, H H; Hansen, O; Hölker, G; Idh, J; Ippolitov, M S; Jacobs, P; Kampert, K H; Karadzhev, K; Kolb, B W; Lebedev, A; Löhner, H; Lund, I; Man'ko, V I; Moskowitz, B E; Nikolaev, S; Nystrand, J; Obenshain, F E; Oskarsson, A; Otterlund, I; Peitzmann, Thomas; Plasil, F; Poskanzer, A M; Purschke, M L; Ritter, H G; Roters, B; Saini, S; Santo, R; Schlagheck, H; Schmidt, H R; Söderström, K; Sørensen, S P; Stankus, P; Steffens, K; Steinhäuser, P; Stenlund, E; Stüken, D; Vinogradov, A; Wegner, H; Young, G R

    1996-01-01

    A search for the production of direct photons in S+Au collisions at 200\\cdotA~GeV has been carried out in the CERN-WA80 experiment. For central collisions the measured photon excess at each p_T, averaged over the range 0.5~GeV/c~ \\leq p_T \\leq 2.5~GeV/c, corresponded to 5.0\\% of the total inclusive photon yield with a statistical error of \\sigma_{\\rm stat}=0.8\\% and a systematic error of \\sigma_{\\rm syst}=5.8\\%. Upper limits on the invariant yield for direct photon production at the 90\\%~C.L. are presented. Possible implications for the dynamics of high-energy heavy-ion collisions are discussed.

  7. Measurement of long-range angular correlations and azimuthal anisotropies in high-multiplicity $p$$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Aidala, C; Alfred, M; Andrieux, V; Apadula, N; Asano, H; Azmoun, B; Babintsev, V; Bandara, N S; Barish, K N; Bathe, S; Bazilevsky, A; Beaumier, M; Belmont, R; Berdnikov, A; Berdnikov, Y; Blau, D S; Bok, J S; Brooks, M L; Bryslawskyj, J; Bumazhnov, V; Campbell, S; Cervantes, R; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Citron, Z; Cronin, N; Csanád, M; Csörgő, T; Danley, T W; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dion, A; Dixit, D; Do, J H; Drees, A; Drees, K A; Durham, J M; Durum, A; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fan, W; Feege, N; Fields, D E; Finger, M; Finger, M; Jr., \\,; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukuda, Y; Gal, C; Gallus, P; Garg, P; Ge, H; Giordano, F; Goto, Y; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Guragain, H; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamilton, H F; Han, S Y; Hanks, J; Hasegawa, S; Haseler, T O S; He, X; Hemmick, T K; Hill, J C; Hill, K; Hollis, R S; Homma, K; Hong, B; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Imai, K; Inaba, M; Iordanova, A; Isenhower, D; Ivanishchev, D; Jacak, B V; Jezghani, M; Jiang, X; Johnson, B M; Jouan, D; Jumper, D S; Kang, J H; Kapukchyan, D; Karthas, E; Kawall, D; Kazantsev, A V; Khachatryan, V; Khanzadeev, A; Kim, C; Kim, E -J; Kim, M; Kincses, D; Kistenev, E; Klatsky, J; Kline, P; Koblesky, T; Kotov, D; Kudo, S; Kurita, K; Kwon, Y; Lajoie, J G; Lebedev, A; Lee, S; Leitch, M J; Leung, Y H; Li, X; Lim, S H; Liu, M X; Loggins, V-R; Lovasz, K; Lynch, D; Majoros, T; Makdisi, Y I; Makek, M; Manko, V I; Mannel, E; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Mendoza, M; Mignerey, A C; Milov, A; Mishra, D K; Mitchell, J T; Mitsuka, G; Miyasaka, S; Mizuno, S; Montuenga, P; Moon, T; Morrison, D P; Murakami, T; Murata, J; Nagai, K; Nagashima, K; Nagashima, T; Nagle, J L; Nagy, M I; Nakagawa, I; Nakano, K; Nattrass, C; Niida, T; Nouicer, R; Novák, T; Novitzky, N; Nyanin, A S; O'Brien, E; Ogilvie, C A; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ottino, G J; Ozawa, K; Pantuev, V; Papavassiliou, V; Park, J S; Park, S; Pate, S F; Patel, M; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; PerezLara, C E; Perry, J; Petti, R; Phipps, M; Pinkenburg, C; Pisani, R P; Purschke, M L; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Rinn, T; Rolnick, S D; Rosati, M; Rowan, Z; Safonov, A S; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seidl, R; Sen, A; Seto, R; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shioya, T; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Snowball, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tanida, K; Tannenbaum, M J; Tarafdar, S; Tarnai, G; Tieulent, R; Timilsina, A; Todoroki, T; Tomášek, M; Towell, C L; Towell, R S; Tserruya, I; Ueda, Y; Ujvari, B; van Hecke, H W; Velkovska, J; Virius, M; Vrba, V; Vukman, N; Wang, X R; Watanabe, Y S; Wong, C P; Woody, C L; Xu, C; Xu, Q; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamamoto, H; Yanovich, A; Yoo, J H; Yoon, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zou, L

    2016-01-01

    We present the first measurements of long-range angular correlations and the transverse momentum dependence of elliptic flow $v_2$ in high-multiplicity $p$$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV. A comparison of these results with previous measurements in high-multiplicity $d$$+$Au and $^3{\\rm He}$$+$Au collisions demonstrates a relation between $v_2$ and the initial collision eccentricity $\\varepsilon_2$, suggesting that the observed momentum-space azimuthal anisotropies in these small systems have a collective origin and reflect the initial geometry. Good agreement is observed between the measured $v_2$ and hydrodynamic calculations for all systems, and an argument disfavoring theoretical explanations based on momentum-space domain correlations is presented. The set of measurements presented here allows us to leverage the distinct intrinsic geometry of each of these systems to distinguish between different theoretical descriptions of the long-range correlations observed in small collision systems.

  8. Bose-Einstein correlations in Si + Al and Si + Au collisions at 14.6A GeV/c

    Science.gov (United States)

    Abbott, T.; Akiba, Y.; Beavis, D.; Bloomer, M. A.; Bond, P. D.; Chasman, C.; Chen, Z.; Chu, Y. Y.; Cole, B. A.; Costales, J. B.

    1992-01-01

    The E802 Spectrometer at the Brookhaven Alternating Gradient Synchrotron has been used to measure the correlation in relative momentum between like-sign pions emitted in central Si + Al and Si + Au collisions at 14.6A GeV/c. Data are presented in terms of the correlation function for both identified pi(-) and pi(+) pairs near the nucleon-nucleon center-of-mass rapidity. All parametrizations of the correlation function are consistent with a spherically symmetric source of rms radius 3.5 +/- 0.4 fm and lifetime fm/c.

  9. Bose-Einstein correlation of kaons in Si + Au collisions at 14.6 A GeV/c

    Science.gov (United States)

    Akiba, Y.; Beavis, D.; Beery, P.; Britt, H. C.; Budick, B.; Chasman, C.; Chen, Z.; Chi, C. Y.; Chu, Y. Y.; Cianciolo, V.

    1993-01-01

    The E-802 spectrometer at the Brookhaven Alternating Gradient Synchrotron, enhanced by a trigger for selection of events with one or more specified particles, has been used to measure the momentum-space correlation between pairs of K(+)s emitted in central Si + Au collisions at 14.6 A GeV/c. This correlation has been projected onto the Lorentz-invariant relative four-momentum axis. Fits to this correlation function yield a size for the kaon source that is comparable to that found using pi(+) pairs from a similar rapidity range, once a transformation from the particle-pair frames to a single source frame is made.

  10. Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at $\\sqrt{s_{NN}} = 200$ GeV

    CERN Document Server

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J T; Barannikova, O Yu; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevshchikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta-Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Yu; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutíerrez, T D; Gagunashvili, N D; Gans, J; Gaudichet, L; Germain, M; Geurts, F J M; Ghazikhanian, V; Ghosh, P; González, J E; Grachov, O A; Grigoriev, V; Gronstal, S; Grosnick, D P; Guedon, M; Guertin, S M; Sen-Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang Sheng Li; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Krämer, M; Kravtsov, P; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Leontiev, V M; Le Vine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Ludlam, Thomas W; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnik, Yu M; Meshchanin, A P; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Mora-Corral, M J; Morozov, V; Moura, A A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevozchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D J; Pruneau, C A; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schröder, L S; Schweda, K; Seger, J; Seliverstov, D M; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimansky, S S; Singaraju, R N; Simon, F; Skoro, G P; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, Reinhard; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Struck, C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T S; Underwood, D G; Van Buren, G; Van der Molen, A M; Vasilev, A N; Vasilev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevsky, Yu V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zolnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

    2005-01-01

    Identified mid-rapidity particle spectra of $\\pi^{\\pm}$, $K^{\\pm}$, and $p(\\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor ($R_{dAu}$) between $(p+\\bar{p})$ and charged hadrons ($h$) in the transverse momentum range $1.2collisions and shows little centrality dependence. The yield ratio of $(p+\\bar{p})/h$ in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.

  11. Long-range pseudorapidity dihadron correlations in d+Au collisions at sNN=200 GeV

    Directory of Open Access Journals (Sweden)

    L. Adamczyk

    2015-07-01

    Full Text Available Dihadron angular correlations in d+Au collisions at sNN=200 GeV are reported as a function of the measured zero-degree calorimeter neutral energy and the forward charged hadron multiplicity in the Au-beam direction. A finite correlated yield is observed at large relative pseudorapidity (Δη on the near side (i.e. relative azimuth Δϕ∼0. This correlated yield as a function of Δη appears to scale with the dominant, primarily jet-related, away-side (Δϕ∼π yield. The Fourier coefficients of the Δϕ correlation, Vn=〈cos⁡nΔϕ〉, have a strong Δη dependence. In addition, it is found that V1 is approximately inversely proportional to the mid-rapidity event multiplicity, while V2 is independent of it with similar magnitude in the forward (d-going and backward (Au-going directions.

  12. Isolation of flow and nonflow correlations by two- and four-particle cumulant measurements of azimuthal harmonics in sNN=200 GeV Au+Au collisions

    Directory of Open Access Journals (Sweden)

    N.M. Abdelwahab

    2015-05-01

    Full Text Available A data-driven method was applied to Au+Au collisions at sNN=200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance Δη-dependent and Δη-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a Δη-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity |η|0.7.

  13. Elliptic Flow Study of Charmed Mesons in 200 GeV Au+Au Collisions at the Relativistic Heavy Ion Collider

    Science.gov (United States)

    Hamad, Ayman

    collaboration built a new micro-vertex detector and installed it in the experiment in 2014. This state-of-the-art silicon pixel technology is named the Heavy Flavor Tracker (HFT). The HFT was designed in order to perform direct topological reconstruction of the weak decay products from hadrons that include a heavy quark. The HFT consists of four layers of silicon, and it improves the track pointing resolution of the STAR experiment from a few mm to around 30 mum for charged pions at a momentum of 1 GeV/c. In this dissertation, I focus on one of the main goals of the HFT detector, which is to study the elliptic flow v2 (a type of azimuthal anisotropy) for D0 mesons in Au+Au collisions at vsNN = 200 GeV. My analysis is based on the 2014 data set (about 1.2 billion collisions covering all impact parameters) that include data from the HFT detector. There are two new and unique analysis elements used in this dissertation. First, I performed the analysis using a Kalman filter algorithm to reconstruct the charmed-meson candidates. The standard reconstruction is via a simple helix-swim method. The advantage of using the Kalman algorithm is in the use of the full error matrix of each track in the vertex estimation and reconstruction of the properties of the heavy-flavor parent particle. Second, I also used the Tool for Multivariate Analysis (TMVA), a ROOT-environment tool, to its full potential for signal significance optimization, instead of the previous approach based on a set of fixed cuts for separating signal from background. This dissertation presents the elliptic component (v2) of azimuthal anisotropy of D0 mesons as a function of transverse momentum, pT. The centrality (impact parameter) dependence of D0 v2(pT) is also studied. Results are compared with similar studies involving light quarks, and with the predictions of several theoretical models.

  14. PHENIX results on collectivity tests in high-multiplicity p + p and p + Au collisions at √{sNN} = 200 GeV

    Science.gov (United States)

    Nakagawa, Itaru

    2016-12-01

    The observation of possible collective effects in high-multiplicity p+p and p+Pb collisions at the LHC and in d+Au and 3He+Au collisions at RHIC challenge our understanding of the ingredients necessary for quark-gluon plasma formation. For further investigation of these effects, the PHENIX collaboration has taken high statistics data in p+p and p+Au and p+Al collisions in 2015. For these data sets, high-multiplicity triggers were implemented using the forward silicon detector (FVTX) and the beam-beam counter (BBC) covering pseudo-rapidity 1.0 < | η | < 3.0 and 3.1 < | η | < 3.9, respectively. The multi-hundred million high-multiplicity event samples recorded enable highly differential analysis to look for collective effects. We report results on large pseudo-rapidity separation correlations to elucidate if the so-called ridge phenomena exists in certain p+p event classes at RHIC. The flow coefficients from azimuthal anisotropies in p+Au are extracted and compared with theoretical expectations in various models, including viscous hydrodynamics where the elliptic flow strength is expected to be substantially smaller than in d+Au and 3He+Au at the same energy due to the smaller initial spatial eccentricity.

  15. Scale-dependence of transverse momentum correlations in Pb-Au collisions at 158A GeV/c

    CERN Document Server

    Adamová, D; Antonczyk, D; Appelshäuser, H; Belaga, V; Bielcikova, S; Braun-Munzinger, P; Busch, O; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Dubitzky, W; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Zeev; Garabatos, C; Glässel, P; Holeczek, J; Kushpil, V; Maas, A; Marín, A; Milosevic, J; Milov, A; Miskowiec, D; Panebratsev, Yu A; Petchenova, O; Petracek, V; Pfeiffer, A; Ploskon, M; Radomski, S; Rak, acn J; Ravinovich, I; Rehak, P; Sako, H; Schmitz, W; Sedykh, S; Shimansky, S; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Tsiledakis, G; Wessels, J P; Wienold, T; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2008-01-01

    We present results on transverse momentum correlations of charged particle pairs produced in Pb-Au collisions at 158$A$ GeV/$c$ at the Super Proton Synchrotron. The transverse momentum correlations have been studied as a function of collision centrality, angular separation of the particle pairs, transverse momentum and charge sign. We demonstrate that the results are in agreement with previous findings in scale-independent analyses at the same beam energy. Employing the two-particle momentum correlator $$ and the cumulative $p_t$ variable $x(p_t)$, we identify, using the scale-dependent approach presented in this paper, different sources contributing to the measured correlations, such as quantum and Coulomb correlations, elliptic flow and mini-jet fragmentation.

  16. Charge exchange and X-ray emission in 70 MeV/u Bi-Au collisions

    Energy Technology Data Exchange (ETDEWEB)

    Verma, P. [GSI, D-64291 Darmstadt (Germany) and Vaish College, Rohtak 124 001 (India) and J. Liebig University, D-35392 Giessen (Germany)]. E-mail: P.Verma@gsi.de; Mokler, P.H. [GSI, D-64291 Darmstadt (Germany); JMI University, New Delhi 110 025 (India); Braeuning-Demian, A. [GSI, D-64291 Darmstadt (Germany); Braeuning, H. [JMI University, New Delhi 110 025 (India); Berdermann, E. [GSI, D-64291 Darmstadt (Germany); Chatterjee, S. [GSI, D-64291 Darmstadt (Germany); Gumberidze, A. [GSI, D-64291 Darmstadt (Germany); Hagmann, S. [J.W. Goethe University, D-60486 Frankfurt (Germany); Kozhuharov, C. [GSI, D-64291 Darmstadt (Germany); Orsic-Muthig, A. [GSI, D-64291 Darmstadt (Germany); Reuschl, R. [J.W. Goethe University, D-60486 Frankfurt (Germany); Schoeffler, M. [J.W. Goethe University, D-60486 Frankfurt (Germany); Spillmann, U. [GSI, D-64291 Darmstadt (Germany); Stoehlker, Th. [GSI, D-64291 Darmstadt (Germany); Stachura, Z. [Institute for Nuclear Physics, PL-31-342 Cracow (Poland); Tashenov, S. [GSI, D-64291 Darmstadt (Germany); Wahab, M.A. [Vaish College, Rohtak 124 001 (India)

    2005-07-01

    Charge exchange and X-ray emission for 70 MeV/u highly charged ions of Bi {sup q+} [77 q 82] colliding with thin Au targets [21 t in {mu}g/cm{sup 2} 225] were measured at the heavy ion synchrotron SIS at GSI. For the innermost shells this beam energy implies a quasiadiabatic collision regime. The charge state distribution of the emerging ions was measured by a position sensitive CVD-diamond detector after being analyzed by a magnet spectrometer. Charge exchange cross sections have been deduced from the target thickness dependence of the charge state distribution. Electron capture at distant collision dominates completely over ionization at close collision. The X-ray emission from the collision partners were measured by solid state detectors, Ge(i). The K X-ray emission for closed and open incoming projectile K vacancies gives access to vacancy transfer in the superheavy quasi-molecule transiently formed during collision for the innermost shells.

  17. Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Angerami, A; Aoki, K; Apadula, N; Aramaki, Y; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Caringi, A; Chen, C-H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Conesa del Valle, Z; Connors, M; Csanád, M; Csörgo, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Dayananda, M K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; D'Orazio, L; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-Å; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ikeda, Y; Imai, K; Inaba, M; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Ivanischev, D; Iwanaga, Y; Jacak, B V; Jia, J; Jiang, X; Jin, J; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kamin, J; Kang, J H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, D J; Kim, E J; Kim, Y-J; Kinney, E; Kiss, Á; Kistenev, E; Kochenda, L; Komkov, B; Konno, M; Koster, J; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Leitch, M J; Leite, M A L; Li, X; Lichtenwalner, P; Liebing, P; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Miki, K; Milov, A; Mitchell, J T; Mohanty, A K; Moon, H J; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murakami, T; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Newby, J; Nguyen, M; Nihashi, M; Nouicer, R; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, S K; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Petti, R; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Themann, H; Thomas, D; Thomas, T L; Togawa, M; Toia, A; Tomášek, L; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zhou, S; Zolin, L

    2011-10-21

    Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|hadron at forward rapidity (deuteron direction, 3.0hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities. © 2011 American Physical Society

  18. Measurement of Elliptic Llow in p+Au Collisions at √SNN = 200 GeV Using the PHENIX Detector at RHIC

    Science.gov (United States)

    Koblesky, Theodore E.

    The Quark Gluon Plasma (QGP), a hot and dense state of matter in which quarks are not confined inside hadrons, is thought to be the same as the matter comprising the entire universe approximately one microsecond after the Big Bang. In Au+Au collisions at √SNN = 200 GeV at the Relativistic Heavy Ion Collider (RHIC) and Pb+Pb collisions at √ SNN = 2.76 TeV at the Large Hadron Collider (LHC), QGP has been discovered to have unique properties, such as its opacity to color charges and the fact that it behaves like a near-perfect fluid. Collective behavior in the form of a substantial elliptical azimuthal anisotropy ( v2) in the momentum distribution of final state particles has been observed, indicating a strongly-coupled, hydrodynamically flowing medium. Recently, features of collectivity have been detected in high-multiplicity, small collision systems thought to be too small to produce the QGP, such as 3He+Au and d+Au at √SNN = 200 GeV, p+Pb at √SNN = 5 TeV, and in p+p = 13 TeV events. In order to constrain models seeking to describe this phenomena, collision systems with distinct initial collision geometries were run at RHIC: 3He+Au for triangular geometry, d+Au for elliptical geometry, and p+Au for circular geometry. Together with coauthors, in a theory paper published in 2014, we proposed the suite of measurements at RHIC of the three collision systems. This thesis is the completion of that set of three measurements, by measuring v2 in the p+Au system. This thesis gives details on the analysis techniques used to make the measurement including the quality assurance of the data, the optimization of the midrapidity charged hadron cuts, and the event plane angle calibration. Special attention is given to correcting the systematic effects produced by the beam alignment unique to the p+Au dataset in order to make the v2 measurement with sufficient precision. Comparisons of v2 in the three collision systems and various theoretical models are made and it appears to

  19. High-p(T) Tomography of d+Au and Au+Au at SPS, RHIC, and LHC.

    Science.gov (United States)

    Vitev, Ivan; Gyulassy, Miklos

    2002-12-16

    The interplay of nuclear effects on the p(T)>2 GeV inclusive hadron spectra in d+Au and Au+Au reactions at sqrt[s(NN)]=17, 200, and 5500 GeV is compared to leading order perturbative QCD calculations for elementary p+p (p+p) collisions. The competition between nuclear shadowing, Cronin effect, and jet energy loss due to medium-induced gluon radiation is predicted to lead to a striking energy dependence of the nuclear suppression/enhancement pattern in A+A reactions. We show that future d+Au data can be used to disentangle the initial and final state effects.

  20. Measurements of elliptic and triangular flow in high-multiplicity $^{3}$He$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$~GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Appelt, E; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Castera, P; Chang, B S; Chang, W C; Charvet, J -L; Chen, C -H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; del Valle, Z Conesa; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Grim, G; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guo, L; Gustafsson, H -Å; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harada, H; Harper, C; Hartouni, E P; Haruna, K; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, G W; Kim, M; Kim, S H; Kim, Y -J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Norman, B E; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Savastio, M; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shevel, A; Shibata, T -A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Snowball, M; Sodre, T; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, D; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Tomita, Y; Torii, H; Towell, C L; Towell, R; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Yoo, J H; Yoo, J S; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimamyi, J; Zolin, L; Zou, L

    2015-01-01

    We present the first measurement of elliptic ($v_2$) and triangular ($v_3$) flow in high-multiplicity $^{3}$He$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$~GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in $^{3}$He$+$Au and in $p$$+$$p$ collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the $^{3}$He$+$Au system. The collective behavior is quantified in terms of elliptic $v_2$ and triangular $v_3$ anisotropy coefficients measured with respect to their corresponding event planes. The $v_2$ values are comparable to those previously measured in $d$$+$Au collisions at the same nucleon-nucleon center-of-mass energy. Comparison with various theoretical predictions are made, including to models where the hot spots created by the impact of the three $^{3}$He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may...

  1. $\\phi$ meson production in the forward/backward rapidity region in Cu$+$Au collisions at $\\sqrt{s_{NN}}=200$ GeV

    CERN Document Server

    Adare, A; Ajitanand, N N; Akiba, Y; Akimoto, R; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Appelt, E; Aramaki, Y; Armendariz, R; Asano, H; Aschenauer, E C; Atomssa, E T; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Bai, X; Bandara, N S; Bannier, B; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Beaumier, M; Beckman, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Black, D; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Castera, P; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Choudhury, R K; Christiansen, P; Chujo, T; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; del Valle, Z Conesa; Connors, M; Cronin, N; Crossette, N; Csanád, M; Csörgő, T; Dairaku, S; Danley, D; Datta, A; Daugherity, M S; David, G; Dayananda, M K; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Efremenko, Y V; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Gallus, P; Garg, P; Garishvili, A; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guo, L; Guragain, H; Gustafsson, H -Å; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harper, C; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Hemmick, T K; Hester, T; Hill, J C; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Iordanova, A; Isenhower, D; Ishihara, M; Isinhue, A; Issah, M; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kamin, J; Kanda, S; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, C; Kim, D J; Kim, E -J; Kim, G W; Kim, M; Kim, Y -J; Kim, Y K; Kimelman, B; Kinney, E; Kiss, Á; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kofarago, M; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Král, A; Krizek, F; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, G H; Lee, J; Lee, K B; Lee, K S; Lee, S; Lee, S H; Lee, S R; Leitch, M J; Leite, M A L; Leitgab, M; Lewis, B; Li, X; Lim, S H; Levy, L A Linden; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; Mao, Y; Maruyama, T; Masui, H; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Miki, K; Milov, A; Mishra, D K; Mitchell, J T; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Mohapatra, S; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Moskowitz, M; Motschwiller, S; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagashima, K; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Ogilvie, C A; Oide, H; Oka, M; Okada, K; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J S; Park, S; Park, S K; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Qu, H; Rak, J; Ramson, B J; Ravinovich, I; Read, K F; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Riveli, N; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosendahl, S S E; Rowan, Z; Rubin, J G; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Savastio, M; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Sekiguchi, Y; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shaver, A; Shein, I; Shibata, T -A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slunečka, M; Snowball, M; Sodre, T; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Stone, M R; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Themann, H; Thomas, D; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Tomášek, L; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; Whitaker, S; White, A S; White, S N; Winter, D; Wolin, S; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xue, L; Yalcin, S; Yamaguchi, Y L; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Yoo, J H; Yoo, J S; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S; Zou, L

    2015-01-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has measured $\\phi$ meson production and its nuclear modification in asymmetric Cu$+$Au heavy-ion collisions at $\\sqrt{s_{NN}}=200$ GeV at both forward Cu-going direction ($1.2Au-going direction ($-2.2Au-going direction. Additionally, the nuclear-modification factor in Cu$+$Au collisions averaged over all centrality is measured to be similar to the previous PHENIX result in $d$$+$Au collisions for these rapidities.

  2. AU BURKINA FASO

    African Journals Online (AJOL)

    Les moyennes sur la même ligne et possédant le même indice ne diffèrent pas significativement au seuil de 5 %. ME : mélange fourrager. 10-20-30 % : pourcentage de concentré. GMQ : Gain Moyen Quotidien. L'analyse des résultats des rations. 1 et 2 montre que l'accès au pâturage permet des performances supérieures.

  3. Rapidity density distributions in Au+Au and Au+Ag interactions at 11.6 A GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Nystrand, J.I. [Div. of Cosmic and Subatomic Physis, Lund Univ. (Sweden); Adamovich, M.I.; Aggarwal, M.M.; Alexandrov, Y.A.; Andreeva, N.P.; Anzon, Z.V.; Arora, R.; Avetyan, F.A.; Badyal, S.K.; Basova, E.; Bazarov, I.K.; Bhalla, K.B.; Bhasin, A.; Bhatia, V.S.; Bogdanov, V.G.; Bubnov, V.I.; Burnett, T.H.; Cai, X.; Carshiev, D.A.; Ceitimbetov, A.M.; Chasnikov, I.Y.; Chernova, L.P.; Chernyavsky, M.M.; Eligbaeva, G.Z.; Eremenko, L.E.; Gaitinov, A.S.; Ganssauge, E.R.; Garpman, S.; Gerassimov, S.G.; Graf, C.; Grote, J.; Gulamov, K.G.; Gupta, S.K.; Gupta, V.K.; Jakobsson, B.; Just, L.; Kachroo, S.; Kalyachkina, G.S.; Kanygina, E.K.; Karabova, M.; Kharlamov, S.P.; Kitroo, S.; Krasnov, S.A.; Kumar, V.; Larionova, V.G.; Li, Y.D.; Liu, L.S.; Lokanatan, S.; Lord, J.J.; Lukicheva, N.S.; Luo, S.B.; Maksimkina, T.N.; Mangotra, L.K.; Marutyan, N.A.; Maslennikova, N.V.; Mittra, I.S.; Mookerjee, S.; Musulmanbekov, J.J.; Nasyrov, S.Z.; Navotny, V.S.; Ochs, M.; Orlova, G.I.; Otterlund, I.; Peresadko, N.G.; Petrov, N.V.; Plyushchev, V.A.; Qian, W.Y.; Qin, Y.M.; Raniwala, R.; Raniwala, S.; Rao, N.K.; Roeper, M.; Saidkhanov, N.; Salmanova, N.A.; Sarkisova, L.G.; Sarkisyan, V.R.; Shabratova, G.S.; Shakhova, T.I.; Shpilev, S.N.; Skelding, D.; Soederstrom, K.; Solovjeva, Z.I.; Stenlund, E; Surin, E.L.; Svechnikova, L.N.; Tolstov, K.D.; Tothova, M.; Tretyakova, M.I.; Trofimova, T.P.; Tuleeva, U.; Tursunov, B.P.; Vokal, S.; Vrlakova, J.; Wang, H.Q.; Weng, Z.Q.; Wilkes, R.J.; Xia, Y.L.; Yang, C.B.; Zhang, D.H.; Zheng, P.Y.; Zhokhova, S.I.; Zhou, D.C.; EMU01 Collaboration

    1994-01-03

    Pseudorapidity density distributions of charged particles in heavy-ion collisions have been studied. The results from EMU01 have been compared to the results from the experiments WA80 and E802. The recently obtained pseudorapidity distributions from Au+Au and Au+Ag interactions have been compared to a linear extrapolation from lighter systems. (orig.)

  4. Detailed analysis of two particle correlations in central Pb-Au collisions at 158 GeV per nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Antonczyk, D.

    2006-07-01

    This thesis presents a two-particle correlation analysis of the fully calibrated high statistics CERES Pb+Au collision data at the top SPS energy, with the emphasis on the pion-proton correlations and the event-plane dependence of the correlation radii. CERES is a dilepton spectrometer at CERN SPS. After the upgrade, which improved the momentum resolution and extended the detector capabilities to hadrons, CERES collected 30 million Pb+Au events at 158 AGeV in the year 2000. A previous Hanbury-Brown-Twiss (HBT) analysis of pion pairs in a subset of these data, together with the results obtained at other beam energies, lead to a new freeze-out criterion [AAA+03]. In this work, the detailed transverse momentum and event-plane dependence of the pion correlation radii, as well as the pion-proton correlations, are discussed in the framework of the blast wave model of the expanding fireball. Furthermore, development of an electron drift velocity gas monitor for the ALICE TPC sub-detector is presented. The new method of the gas composition monitoring is based on the simultaneous measurement of the electron drift velocity and the gas gain and is sensitive to even small variations of the gas mixture composition. Several modifications of the apparatus were performed resulting in the final drift velocity resolution of 0.3 permille. (orig.)

  5. Participant and spectator scaling of spectator fragments in Au+Au and Cu+Cu collisions at sqrt(sNN) = 19.6 and 22.4 GeV

    CERN Document Server

    Alver, B; Baker, M D; Ballintijn, M; Barton, D S; Betts, R R; Bickley, A A; Bindel, R; Budzanowski, A; Busza, W; Carroll, A; Chai, Z; Chetluru, V; Decowski, M P; Garcia, E; Gburek, T; George, N; Gulbrandsen, K; Gushue, S; Halliwell, C; Hamblen, J; Harnarine, I; Heintzelman, G A; Henderson, C; Hofman, D J; Hollis, R S; Holynski, R; Holzman, B; Iordanova, A; Johnson, E; Kane, J L; Katzy, J; Khan, N; Kucewicz, W; Kulinich, P; Kuo, C M; Li, W; Lin, W T; Loizides, C; Manly, S; McLeod, D; Mignerey, A C; Nouicer, R; Olszewski, A; Pak, R; Park, I C; Pernegger, H; Reed, C; Remsberg, L P; Reuter, M; Richardson, E; Roland, C; Roland, G; Rosenberg, L; Sagerer, J; Sarin, P; Sawicki, P; Sedykh, I; Skulski, W; Smith, C E; Stankiewicz, M A; Steinberg, P; Stephans, G S F; Sukhanov, A; Szostak, A; Tang, J L; Tonjes, M B; Trzupek, A; Vale, C; van Nieuwenhuizen, G J; Vaurynovich, S S; Verdier, R; Veres, G I; Walters, P; Wenger, E; Willhelm, D; Wolfs, F L H; Wosiek, B; Wozniak, K; Wuosmaa, A H; Wyngaardt, S; Wyslouch, B

    2015-01-01

    Spectator fragments resulting from relativistic heavy ion collisions, consisting of single protons and neutrons along with groups of stable nuclear fragments up to Nitrogen (Z=7), are measured in PHOBOS. These fragments are observed in Au+Au (sqrt(sNN)=19.6 GeV) and Cu+Cu (22.4 GeV) collisions at high pseudorapidity ($\\eta$). The dominant multiply-charged fragment is the tightly bound Helium ($\\alpha$), with Lithium, Beryllium, and Boron all clearly seen as a function of collision centrality and pseudorapidity. We observe that in Cu+Cu collisions, it becomes much more favorable for the $\\alpha$ fragments to be released than Lithium. The yields of fragments approximately scale with the number of spectator nucleons, independent of the colliding ion. The shapes of the pseudorapidity distributions of fragments indicate that the average deflection of the fragments away from the beam direction increases for more central collisions. A detailed comparison of the shapes for $\\alpha$ and Lithium fragments indicates tha...

  6. Event by event measurement of (p(T)) of photons in S+Au collisions at 200 A center dot GeV

    NARCIS (Netherlands)

    Aggarwal, MM; Angelis, ALS; Antonenko, [No Value; Awes, TC; Badyal, SK; Barlag, C; Bhalla, KB; Bhatia, VS; Blume, C; Bock, D; Bohne, EM; Bucher, D; Buijs, A; Chattopadhyay, S; Claussen, A; Clewing, G; Das, AC; Devanand, [No Value; Donni, P; Durieux, E; Majumdar, MRD; Fokin, S; Ganti, MS; Garpman, S; Geurts, F; Ghosh, TK; Glasow, R; Gupta, SK; Gustafsson, H.A.; Gutbrod, HH; Hartig, M; Holker, G; Ippolitov, M; Izycki, M; Kachroo, S; Kamermans, R; Kampert, KH; Karadjev, K; Kolb, BW; Langbein, [No Value; Langheinrich, J; Lebedev, A; Lohner, H; Manko, [No Value; Martin, M; Mittra, IS; Naef, H; Nayak, SK; Nayak, TK; Nikolaev, S; Nystrand, J; Obenshain, FE; Oskarsson, A; Otterlund, [No Value; Peitzmann, T; Plasil, F; Purschke, M; Raniwala, S; Rao, NK; Rosselet, L; Roters, B; Rubio, JM; Saini, S; Sambyal, S; Santo, R; Siemiarczuk, T; Siemssen, R; Sinha, BC; Slegt, S; Soderstrom, K; Solomey, N; Sorensen, SP; Stefanek, G; Steinhaeuser, P; Stenlund, E; Ster, A; Stuken, D; Trivedi, MD; Twenhoefel, C; VanEijndhoven, N; VanHeeringen, WH; Vinogradov, A; Viyogi, YP; Young, GR

    1997-01-01

    The mean transverse momentum of photons has been determined on an event by event basis in S + Au collisions at 200 A.GeV from the ratio of the measured electromagnetic transverse energy (E-T(em)) to the photon multiplicity (N-gamma). The average value obtained is similar to that determined for the

  7. Di-electron spectroscopy in HADES and CBM. From p+p and n+p collisions at GSI to Au+Au collisions at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Galatyuk, Tetyana

    2009-07-17

    In this work the di-electron production in p+p and d+p reactions at a kinetic beam energy of 1.25 GeV/u measured by the HADES spectrometer is discussed. At E{sub kin}=1.25 GeV/u, i.e. below the {eta} meson production threshold in proton-proton reactions, the {delta} Dalitz decay is expected to be the most abundant source above the {pi}{sup 0} Dalitz decay region. The observed large difference in di-electron production in p+p and d+p collisions suggests that di-electron production in the d+p system is dominated by the n+p interaction. In order to separate {delta} Dalitz decays and np bremsstrahlung the di-electron yield observed in p+p and n+p reactions, both measured at the same beam energy, has been compared. The main interest here is the investigation of iso-spin effects in baryonic resonance excitations and the off-shell production of vector mesons. We indeed observe a large difference in di-electron production in p+p and n+p reactions. Results of these studies will be compared to recent calculations. We will also present our experimentally defined cocktail for heavy-ion data. A strong excess of lepton pairs observed by recent high energy heavy-ion dilepton experiments hint to a strong influence of baryons, however no data exist at highly compressed baryonic matter, achievable in heavy-ion collisions from 8.45 GeV/u beam energy. These conditions would allow to study the expected restoration of chiral symmetry by measuring in-medium modifications of hadronic properties, an experimental program which is foreseen by the future CBM experiment at FAIR. The experimental challenge is to suppress the large physical background on the one hand and to provide a clean identification of electrons on the other hand. In this work, strategies to reduce the combinatorial background in electron pair measurements with the CBM detector are discussed. The main goal is to study the feasibility of effectively reducing combinatorial background with the currently foreseen experimental

  8. Measurements of directed, elliptic, and triangular flow in Cu$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Ajitanand, N N; Akiba, Y; Akimoto, R; Alexander, J; Alfred, M; Aoki, K; Apadula, N; Asano, H; Atomssa, E T; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Bai, X; Bandara, N S; Bannier, B; Barish, K N; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Beaumier, M; Beckman, S; Belmont, R; Berdnikov, A; Berdnikov, Y; Black, D; Blau, D S; Bok, J S; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Butsyk, S; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Christiansen, P; Chujo, T; Cianciolo, V; Citron, Z; Cole, B A; Cronin, N; Crossette, N; Csanád, M; Csörgő, T; Danley, D; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Ding, L; Dion, A; Diss, P B; Do, J H; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Engelmore, T; Enokizono, A; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fusayasu, T; Gainey, K; Gal, C; Gallus, P; Garg, P; Garishvili, A; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guragain, H; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamilton, H F; Han, S Y; Hanks, J; Hasegawa, S; Haseler, T O S; Hashimoto, K; Hayano, R; He, X; Hemmick, T K; Hester, T; Hill, J C; Hollis, R S; Homma, K; Hong, B; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Iordanova, A; Isenhower, D; Isinhue, A; Ivanishchev, D; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kamin, J; Kanda, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Kawall, D; Kazantsev, A V; Key, J A; Khachatryan, V; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, C; Kim, D J; Kim, E -J; Kim, G W; Kim, M; Kim, Y -J; Kim, Y K; Kimelman, B; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kofarago, M; Komkov, B; Koster, J; Kotchetkov, D; Kotov, D; Krizek, F; Kurita, K; Kurosawa, M; Kwon, Y; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, G H; Lee, J; Lee, K B; Lee, K S; Lee, S; Lee, S H; Leitch, M J; Leitgab, M; Lewis, B; Li, X; Lim, S H; Liu, M X; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; Maruyama, T; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Milov, A; Mishra, D K; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Mohapatra, S; Montuenga, P; Moon, T; Morrison, D P; Moskowitz, M; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagae, T; Nagamiya, S; Nagashima, K; Nagle, J L; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Netrakanti, P K; Nihashi, M; Niida, T; Nishimura, S; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; O'Brien, E; Ogilvie, C A; Oide, H; Okada, K; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J S; Park, S; Park, S K; Pate, S F; Patel, L; Patel, M; Peng, J -C; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Purschke, M L; Qu, H; Rak, J; Ramson, B J; Ravinovich, I; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Riveli, N; Roach, D; Rolnick, S D; Rosati, M; Rowan, Z; Rubin, J G; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, S; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Sekiguchi, Y; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shaver, A; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slunečka, M; Snowball, M; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Stone, M R; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Takahara, A; Taketani, A; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Tieulent, R; Timilsina, A; Todoroki, T; Tomášek, M; Torii, H; Towell, C L; Towell, R; Towell, R S; Tserruya, I; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Whitaker, S; White, A S; Wolin, S; Woody, C L; Wysocki, M; Xia, B; Xue, L; Yalcin, S; Yamaguchi, Y L; Yanovich, A; Yokkaichi, S; Yoo, J H; Yoon, I; You, Z; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S; Zou, L

    2015-01-01

    Measurements of anisotropic flow Fourier coefficients ($v_n$) for inclusive charged particles and identified hadrons $\\pi^{\\pm}$, $K^{\\pm}$, $p$, and $\\bar{p}$ produced at midrapidity in Cu+Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV are presented. The data were collected in 2012 by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). The particle azimuthal distributions with respect to different order symmetry planes $\\Psi_n$, for $n$~=~1, 2, and 3 are studied as a function of transverse momentum $p_T$ over a broad range of collisions centralities. Mass ordering, as expected from hydrodynamic flow, is observed for all three harmonics. The charged-particle results are compared to hydrodynamical and transport model calculations. We also compare these Cu$+$Au results with those in Cu$+$Cu and Au$+$Au collisions at the same $\\sqrt{s_{_{NN}}}$, and find that the $v_2$ and $v_3$, as a function of transverse momentum, follow a common scaling with $1/(\\varepsilon_n N_{\\rm part}^{1/3})$.

  9. Au pair trajectories

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send...

  10. Catalytic activity of Au nanoparticles

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Janssens, Ton V.W.; Clausen, Bjerne

    2007-01-01

    Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change with par......Au is usually viewed as an inert metal, but surprisingly it has been found that Au nanoparticles less than 3–5 nm in diameter are catalytically active for several chemical reactions. We discuss the origin of this effect, focusing on the way in which the chemical activity of Au may change...... with particle size. We find that the fraction of low-coordinated Au atoms scales approximately with the catalytic activity, suggesting that atoms on the corners and edges of Au nanoparticles are the active sites. This effect is explained using density functional calculations....

  11. Identified hadron production in s = 130 GeV Au–Au collisions at ...

    Indian Academy of Sciences (India)

    collisions at relativistic heavy-ion collider. JULIA VELKOVSKA, for the ... faster than the π· yields. We combine the. PHENIX neutral and charged pion measurement and find that in central collisions for pT ... identified charged hadron spectra and used those in conjuction with the PHENIXπ 0 spectra [3] to obtain high-pT par-.

  12. Measurement of electrons from heavy-flavor decays from $p$+$p$, $d$+Au, and Cu+Cu collisions in the PHENIX experiment

    CERN Document Server

    Lim, Sanghoon

    2014-01-01

    Charm and bottom quarks are formed predominantly by gluon fusion in the initial hard scatterings at RHIC, making them good probes of the full medium evolution. Previous measurements at RHIC have shown large suppression and azimuthal anisotropy of open heavy-flavor hadrons in Au+Au collisions at $\\sqrt{s_{NN}}=200~{\\rm GeV}$. Explaining the simultaneously large suppression and flow of heavy quarks has been challenging. To further understand the heavy-flavor transport in the hot and dense medium, it is imperative to also measure cold nuclear matter effects which affect the initial distribution of heavy quarks as well as the system size dependence of the final state suppression. In this talk, new measurements by the PHENIX collaboration of electrons from heavy-flavor decays in $p$+$p$, $d$+Au, and Cu+Cu collisions at $\\sqrt{s_{NN}}=200~{\\rm GeV}$ are presented. In particular, a surprising enhancement of intermediate transverse momentum heavy-flavor decay leptons in $d$+Au at mid and backward rapidity are also se...

  13. J/$\\psi$ production and absorption in p plus A and d plus Au collisions

    CERN Document Server

    Vogt, R; Lourenco, C

    2011-01-01

    The level of ``anomalous{''} charmonium suppression in high-energy heavy-ion collisions and its interpretation as a signal of quark-gluon plasma formation requires a robust understanding of charmonium production and absorption in proton-nucleus collisions. In a previous study we have shown that, contrary to common belief, the so-called J/psi, ``absorption cross section{''}, sigma(J/psi)(ubs), is not a ``universal constant{''} but, rather, an effective parameter that depends very significantly on the charmonium rapidity and on the collision energy. Here we present ugraded Glauber calculations with the EPS09 parameterization of nuclear modifications of the parton densities. We confirm that the effective ``absorption cross section{''} depends on the J/psi kinematics and the collision energy. We also make further steps towards understanding the physics of the mechanisms behind the observed ``cold nuclear matter{''} effects.

  14. Reconstruction of charged kaons in the three pion decay channel in Pb+Au 158 AGeV collisions by the CERES experiment

    CERN Document Server

    Kalisky, Matus; Pietralla, Norbert

    Strangeness production in ultra-relativistic nucleus-nucleus collisions is one of the most important probes of hot and dense nuclear matter. Yields and spectra of hadrons carrying strangeness are being studied over a broad range of energies. A remarkable result is that the yields of strange hadrons appear to be in chemical equilibrium in nucleus-nucleus collisions in contrast to observations in elementary collisions. The first part of this thesis is dedicated to the reconstruction of charged kaons in central Pb+Au collisions at the top SPS energy with the CERES pectrometer. The analysis scheme is based on the reconstruction of the decay of charged kaons in three charged pions. This approach is, with the exception of the pioneering work of the NA35 experiment, applied for the first time in ultra relativistic heavy ion collisions for the charged kaons reconstruction. In total 102k K+ and 57k K- were reconstructed in 24.3M central Pb+Au collisions. The mid-rapidity yields are 31.8 for K+ and 19.3 for the K-. The...

  15. Two-particle rapidity correlations between relativistic particles in central collisions of {sup 197}Au nuclei in emulsion at 11.6 A GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Abdurakhmanov, U.U.; Gulamov, K.G.; Navotny, V.Sh. [Fizika-Solntse Research and Production Association, Uzbek Academy of Sciences, Institute for Physics and Technology, Tashkent (Uzbekistan)

    2016-06-15

    It is shown that in central collisions of {sup 197}Au nuclei with heavy emulsion nuclei at 11.6 AGeV/c two-particles pseudorapidity correlations for produced particles in terms of correlation functions demonstrate predominantly long-range behaviour in contrast to nucleon-nucleon interactions. The experimental data are compared with calculations based on the FRITIOF-M model and the model of independent emission of particles. (orig.)

  16. Nuclear Modification of Neutral Pion Production at Low x in √s=200 GeV d+Au and p+p Collisions

    Science.gov (United States)

    Sedgwick, Kenneth Blair

    Nuclear modification factors quantify suppression in particle production due to nuclear effects. They are defined as a ratio of invariant yields, with a numerator derived from a given species of nuclear collision and a denominator derived from a hypothetically equivalent ensemble of independent proton-proton collisions. At large momentum transfer Q 2 and low momentum fraction x, the neutral pion nuclear modification factor Rd+Au for d+Au collisions is useful for investigating initial state gluon saturation. The large initial state gluon multiplicity of the Au nucleus causes saturation effects to occur at lower energies in d+Au collisions, as compared to p+p collisions, resulting in a relative suppression. Measuring the relative suppression R d+Au can therefore test the validity of competing models describing saturation, including the framework of a color glass condensate (CGC). Measurements at low x are of particular interest because in this region linear pQCD evolution equations begin to break down. The Froissart theorem places a robust theoretical upper limit on the behavior of hadronic cross sections: a cross section can increase at most like ln2 E. Equivalently, an hadronic structure function can increase at most like ln2(1/x). Adherence to this theorem is necessary to preserve S-matrix unitarity; no physical system should exhibit behavior to the contrary. However linear evolution equations, which dictate structure function behavior, predict an unchecked growth of low-x gluons, in violation of the theorem. For this reason, it is expected that gluon saturation, via non-linear evolution, will take place at low x to steer the gluon distribution function back within the limitations of the Froissart bound. Greater suppression is expected at lower Q2; however, at low x, regions of high Q 2 are more difficult to access experimentally. Pushing out to higher Q2 is important for discriminating between competing theoretical models. In practice, regions of low x and high Q

  17. Mise au point

    African Journals Online (AJOL)

    31 mai 2013 ... laryngocèle interne. Une surinfection a été notée chez trois patients réalisant ainsi le tableau de pyolaryngocèle. Tous les patients ont eu un examen clinique complet comportant un examen OrL et cervico-facial ainsi qu'un examen laryngé au ... pas en communication avec la lumière laryngée. La taille.

  18. Le CRDI au Mali

    International Development Research Centre (IDRC) Digital Library (Canada)

    sur la sécurité alimentaire internationale. Le CRDI continue de soutenir des travaux de recherche au Mali, quoique dans une moindre mesure en raison de la .... souvent tenues à l'écart du processus décisionnel. Les chercheurs tentent de déterminer de quelles manières les jeunes femmes du Mali et des pays avoisinants ...

  19. Mise au point

    African Journals Online (AJOL)

    7 mai 2012 ... Le carcinome folliculaire est la deuxième tumeur maligne la plus fréquente de la thyroïde et l'invasion hématologique est le moyen de propagation le plus courant de ses métastases. Les localisations secondaires à ces cancers siègent principalement au niveau des poumons, suivi par les localisations.

  20. Le CRDI au Maroc

    International Development Research Centre (IDRC) Digital Library (Canada)

    visant à aider les secteurs de l'agriculture et du tourisme à s'adapter aux changements climatiques. Dans le cadre de recherches antérieures sur la mise au point .... France. Les manifestations et protestations survenues après 2010 et auxquelles on a donné le nom de Printemps arabe ont été annonciatrices de profondes ...

  1. Mise au point

    African Journals Online (AJOL)

    7 mai 2012 ... EPIdEMIOlOgIE ET ETIOPAThOgENIE. Les angiodysplasies osseuses des maxillaires sont rares. Les premiers cas rapportés sont ceux de Berard qui a décrit en 1842 une localisation au niveau du maxillaire supérieur et de Stanley qui a rapporté en 1849 une loca- lisation mandibulaire. une prédisposition ...

  2. Le CRDI au Kenya

    International Development Research Centre (IDRC) Digital Library (Canada)

    et de l'agriculture. En produisant des connaissances dans ces secteurs essentiels, le programme contribuera à la sécurité alimentaire et améliorera la santé au Kenya. Les noms et les frontières indiqués sur la carte n'impliquent ni reconnaissance ni acceptation officielle de la part du CRDI. C. U. R. T. C. A. R. N. EM. A. R. K.

  3. Azimuthal angular distributions of K{sup +} and K{sup -} mesons from Au+Au collisions at a kinetic beam energy of 1.5 AGeV

    Energy Technology Data Exchange (ETDEWEB)

    Ploskon, M.

    2005-07-01

    The Kaon-Spectrometer (KaoS) at the heavy-ion synchrotron (SIS) at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt has been used to study production and propagation of K{sup +} and K{sup -} mesons from Au+Au collisions at a kinetic beam energy of 1.5 AGeV. The azimuthal angular distributions of particles as a function of the collision centrality and particle transverse momenta have been measured. We found a dependence of the K{sup -} meson azimuthal emission pattern on the transverse momentum. The antikaons registered with p{sub t}<0.5 GeV/c are preferentially emitted in the reaction plane and the particles with p{sub t} > 0.5 GeV/c show strong out-of-plane enhancement. The emission patterns of K{sup -} can be explained in terms of two competing phenomena: one of them is indeed the influence of the attractive K{sup -}N potential, however, the second one originates from the strangeness-exchange process. (orig.)

  4. Quarkonia measurement in p+p and d+Au collisions at sqrt(s)=200 GeV by PHENIX Detector

    CERN Document Server

    da Silva, Cesar Luiz

    2009-01-01

    We report new quarkonia measurements necessary to understand production mechanisms and cold nuclear matter effects in the yields observed at RHIC energy. Results obtained in p+p collisions collected during the 2006 RHIC Run include J/psi, Psi' and Upsilon differential cross sections as well as J/psi polarization. Revisited interpretations of the published J/psi nuclear modification factors and statistically improved observations in d+Au collisions taken in the 2008 Run are also discussed in the view of the recent understanding of the initial state effects and breakup cross section.

  5. Azimuthal correlations of forward dihadrons in d + Au collisions at RHIC in the color glass condensate.

    Science.gov (United States)

    Albacete, J L; Marquet, C

    2010-10-15

    We present a good description of recent experimental data on forward dihadron azimuthal correlations measured in deuteron-gold collisions at the BNL Relativistic Heavy Ion Collider (RHIC), where monojet production has been observed. Our approach is based on the color glass condensate theory for the small-x degrees of freedom of the nuclear wave function, including the use of nonlinear evolution equations with running QCD coupling. Our analysis provides further evidence for the presence of saturation effects in RHIC data.

  6. PHENIX results on identified particles spectra and anisotropic flow in p/d/3He+Au collisions at 200 GeV

    Science.gov (United States)

    Peng, Weizhuang; Phenix Collaboration

    2017-09-01

    Recent results from small collision systems at RHIC and LHC indicate that many of the signatures of collective behavior observed in AA collisions are also present in small systems in high-multiplicity events. The PHENIX experiment has performed comprehensive studies of long-range particle correlations and anisotropic flow in collisions. Mass ordering has been observed in the pt distributions of the anisotropic flow coefficients vn. Such mass ordering is a key feature in the hydrodynamics description of the system evolution and arises from radial flow, where all particles move with a common flow velocity. However, the mass ordering is also seen in microscopic transport models such as AMPT. Information about the radial flow can be gained more directly from measurements of the transverse momentum distributions of identified hadrons. Identified particle spectra and anisotropic flow in p/d/3He+Au collisions will be presented and compared to theoretical predictions.

  7. PHENIX results on jets in d + Au

    Science.gov (United States)

    Hanks, J. Ali

    2016-12-01

    We present recently published results [A. Adare, et al., arxiv:arXiv:1509.04657] on fully reconstructed R=0.3 anti-kt jets measured in p+p and d+Au collisions at 200 GeV center-of-mass energy. The jet yields for four centrality classes along with the p+p reference are presented, as well as both the minimum bias RdAu and centrality dependent RdAu and RCP. We find that while the minimum bias RdA is consistent with unity, providing a strong constraint on models including cold-nuclear-matter effects or energy loss in small systems, the centrality dependent RdAu show a striking variation which presents a challenge to models attempting to describe the interplay between soft and hard processes in these systems.

  8. Preparations for p-Au run in 2015

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-12-31

    The p-Au particle collision is a unique category of collision runs. This is resulted from the different charge mass ratio of the proton and fully stripped Au ion (1 vs.79/197). The p-Au run requires a special acceleration ramp, and movement of a number of beam components as required by the beam trajectories. The DX magnets will be moved for the first time in the history of RHIC. In this note, the planning and preparations for p-Au run will be presented.

  9. Mise au point

    African Journals Online (AJOL)

    31 mai 2013 ... L'attitude théra- peutique dépend du type de la laryngocèle. en effet, le traitement endoscopique au laser CO2 a gagné beaucoup d'intérêt ces dernières années. MATÉRIEL ET MÉTHOdES. Il s'agit d'une étude rétrospective portant sur 9 patients porteurs d'une laryngocèle colligés sur une période de 14.

  10. Le CRDI au Ghana

    International Development Research Centre (IDRC) Digital Library (Canada)

    poussée en mathématiques aux spécialistes de demain afin qu'ils puissent relever les défis pressants qui se posent en matière d'environnement, de santé et d'économie. La bourse de chercheur invité que le CRDI a octroyée en 2001 au regretté. John Atta-Mills, qui a par la suite été prési- dent du Ghana de 2009 à 2012, ...

  11. Au pairs on Facebook

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2016-01-01

    Ethnographers are increasingly making use of Facebook to acquire access and general acquaintance with their field of study. However, little has been written on how Facebook is used methodologically in research that does not have social media sites as the main focus of interest. This article argues...... that engagement with Facebook as a methodological tool can be useful in research among migrants in highly politicised fields. Pointing to a discursive construction of Filipina au pairs as victims of labour exploitation, the article shows how fieldwork on Facebook enables the exploration of the ways in which...... and on Facebook....

  12. Mise au point

    African Journals Online (AJOL)

    7 mai 2012 ... acquis et des anomalies génétiques associées ont été aussi incriminés (mutation du gène Fas ou de la p53, délétion au niveau du chromosome 6q, méthylation excessive de la p73) (15,16). Le mode de révélation de ces lymphomes est peu spéci- fique et parfois banal. L'obstruction nasale représente le.

  13. Excitation functions of parameters extracted from three-source (net-)proton rapidity distributions in Au-Au and Pb-Pb collisions over an energy range from AGS to RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Li-Na; Liu, Fu-Hu [Shanxi University, Institute of Theoretical Physics, Taiyuan, Shanxi (China); Sun, Yan; Sun, Zhu [Shanxi Datong University, Department of Physics, Datong, Shanxi (China); Lacey, Roy A. [Stony Brook University, Departments of Chemistry and Physics, Stony Brook, NY (United States)

    2017-03-15

    Experimental results of the rapidity spectra of protons and net-protons (protons minus antiprotons) emitted in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions, measured by a few collaborations at the alternating gradient synchrotron (AGS), super proton synchrotron (SPS), and relativistic heavy ion collider (RHIC), are described by a three-source distribution. The values of the distribution width σ{sub C} and fraction k{sub C} of the central rapidity region, and the distribution width σ{sub F} and rapidity shift Δy of the forward/backward rapidity regions, are then obtained. The excitation function of σ{sub C} increases generally with increase of the center-of-mass energy per nucleon pair √(s{sub NN}). The excitation function of σ{sub F} shows a saturation at √(s{sub NN}) = 8.8 GeV. The excitation function of k{sub C} shows a minimum at √(s{sub NN}) = 8.8 GeV and a saturation at √(s{sub NN}) ∼ 17 GeV. The excitation function of Δy increases linearly with ln(√(s{sub NN})) in the considered energy range. (orig.)

  14. Magnetoresistance of Au films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D. L., E-mail: zhangdl@iphy.ac.cn; Song, X. H.; Zhang, X. [Institute of Physics, Chinese Academy of Sciences, Beijing 10081 (China); Zhang, X.-G., E-mail: xgz@ufl.edu [Department of Physics and Quantum Theory Project, University of Florida, Gainesville, Florida 32611 (United States); Center for Nanophase Materials Sciences and Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6493 (United States)

    2014-12-14

    Classical magnetoresistance (MR) in nonmagnetic metals are conventionally understood in terms of the Kohler rule, with violation usually viewed as anomalous electron transport, in particular, as evidence of non-Fermi liquid behavior. Measurement of the MR of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms. Consequently, the Kohler rule should not be used to distinguish normal and anomalous electron transport in solids.

  15. Effect of viscosity on one dimensional hydrodynamic flow and direct photons from 200 AGeV S+Au collisions at CERN SPS

    CERN Document Server

    Chaudhuri, A K

    2000-01-01

    We have analysed the direct photon data obtained by the WA80 collaboration in 200 A GeV S+Au collision at CERN SPS, in a one dimensional hydrodynamical model. Two scenario was considered: (i) formation of quark-gluon plasma and (ii) formation of hot hadronic gas. For both the scenario, ideal as well as extremely viscous fluid was considered. It was found that direct photon yield from QGP is not affected much whether the fluid is treated as ideal or extremely viscous. The yield however differ substantially if hadron gas is produced. Both the scenario do not give satisfactory description of the data.

  16. d-alpha Correlation functions and collective motion in Xe+Au collisions at E/A=50 MeV

    OpenAIRE

    G. VerdeINFN, Sezione di Catania, Italy; P. Danielewicz(NSCL, Michigan State University, USA); W. G. Lynch(NSCL, Michigan State University, USA); C. F. Chan(NSCL, Michigan State University, USA); C. K. Gelbke(NSCL, Michigan State University, USA); K. K. Lau(NSCL, Michigan State University, USA); T. X. Liu(NSCL, Michigan State University, USA); X. D. Liu(NSCL, Michigan State University, USA); D. Seymour(NSCL, Michigan State University, USA); R. Shomin(NSCL, Michigan State University, USA); W. P. Tan(NSCL, Michigan State University, USA); M. B. Tsang(NSCL, Michigan State University, USA); A. Wagner(NSCL, Michigan State University, USA); H. S. Xu(NSCL, Michigan State University, USA); D. A. Brown(LLNL, USA)

    2015-01-01

    The interplay of the effects of geometry and collective motion on d-$\\alpha$ correlation functions is investigated for central Xe+Au collisions at E/A=50 MeV. The data cannot be explained without collective motion, which could be partly along the beam axis. A semi-quantitative description of the data can be obtained using a Monte-Carlo model, where thermal emission is superimposed on collective motion. Both the emission volume and the competition between the thermal and collective motion infl...

  17. Measurements of jet quenching with semi-inclusive hadron plus jet distributions in Au plus Au collisions at root s(NN)=200 GeV

    Czech Academy of Sciences Publication Activity Database

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Bielčík, J.; Bielčíková, Jana; Chaloupka, P.; Federič, Pavol; Federičová, P.; Harlenderová, A.; Kocmánek, Martin; Kvapil, J.; Lidrych, J.; Rusňák, Jan; Rusňáková, O.; Šaur, Miroslav; Šimko, Miroslav; Šumbera, Michal; Trzeciak, B. A.

    2017-01-01

    Roč. 96, č. 2 (2017), č. článku 024905. ISSN 2469-9985 R&D Projects: GA MŠk LG15001; GA MŠk LM2015054 Institutional support: RVO:61389005 Keywords : STAR collaboration * heavy ion collisions * centrality dependence Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.820, year: 2016

  18. {pi}{sup 0}-mesons and photons measured in Au+Au collisions at an energy of {radical}(s{sub NN})=62 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Wetzler, A.A.

    2006-07-01

    For this thesis photon and {pi}{sup 0} spectra in Gold-Gold-collisions at an energy of {radical}(s{sub NN})=62 GeV were measured using the STAR-experiment at RHIC. The data set is divided into four centrality selection classes. The first result are the transverse momentum and rapidity spectra of inclusive photons for all four centralities and the whole data set. {pi}{sup 0}-spectra versus transverse momentum for the four centralities and the whole data set are also shown. (orig.)

  19. Triangular flow of negative pions emitted in PbAu collisions at $\\sqrt{s_{NN}} $= 17.3~GeV

    CERN Document Server

    Adamová, D.

    Differential triangular flow, $v_3(p_T)$, of negative pions is measured at $\\sqrt{s_{NN}}$= 17.3~GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30\\% with a mean centrality of 5.5\\%. This is the first measurement of the triangular flow at SPS energies. The $p_T$ range extends from about 0.05~GeV/c to more than 2~GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydro calculation combined with an UrQMD cascade model for the late stages.

  20. PHENIX results on centrality dependence of yields and correlations in $d$+Au collisions at $\\sqrt{s_{_{NN}}}$=200\\,GeV

    CERN Document Server

    Sakaguchi, Takao

    2016-01-01

    PHENIX has measured the transverse momentum ($p_{\\rm T}$) spectra and two particle angular correlations for high $p_{\\rm T}$ particles in $d$+Au collisions at $\\sqrt{s_{_{NN}}}$=200\\,GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge like structure. Using the $\\pi^0$ reconstructed in the EMCal, we have successfully extended the $p_{\\rm T}$ reach of the correlation up to 8\\,GeV/$c$. We find that the azimuthal anisotropy of hadrons found at low $p_{\\rm T}$ persists up to 6\\,GeV/$c$ with a significant centrality and $p_{\\rm T}$ dependence, similar to what was observed in A+A collisions.

  1. PHENIX results on centrality dependence of yields and correlations in d + Au collisions at √{sNN} = 200 GeV

    Science.gov (United States)

    Sakaguchi, Takao

    2016-12-01

    PHENIX has measured the transverse momentum (pT) spectra and two particle angular correlations for high pT particles in d+Au collisions at √{sNN} = 200GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge-like structure. Using the π0s reconstructed in the EMCal, we have successfully extended the pT reach of the correlation up to 8GeV/c. We find that the azimuthal anisotropy of hadrons found at low pT persists up to 6GeV/c with a significant centrality and pT dependence, similar to what was observed in A+A collisions.

  2. PHENIX results on centrality dependence of yields and correlations in d plus Au collisions at root s(NN)=200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, T. [Brookhaven National Lab. (BNL), Upton, NY (United States), et al.

    2016-12-01

    PHENIX has measured the transverse momentum (pT) spectra and two particle angular correlations for high pT particles in d+Au collisions at psNN=200 GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge-like structure. Using the pi-0s reconstructed in the EMCal, we have successfully extended the pT reach of the correlation up to 8 GeV/c. We find that the azimuthal anisotropy of hadrons found at low pT persists up to 6 GeV/c with a significant centrality and pT dependence, similar to what was observed in A+A collisions.

  3. Measurement of D0 elliptic flow using the heavy flavor tracker detector in Au+Au collisions at √sNN = 200 GeV

    Science.gov (United States)

    Lipiec, Andrzej

    2017-08-01

    In heavy ion collisions at relativistic energies conducted at Relativistic Heavy Ion Collider (RHIC, Upton, USA) a new state of matter, Quark Gluon Plasma (QGP), is produced. QGP is a state of matter with partonic (i.e. gluons + quarks) degrees of freedom and is believed to be existing only during first moments after the Big Bang, and possibly inside of the heaviest neutron stars. One of the key QGP signatures is the elliptic flow (v2) - a coefficient that describes spatial assymetry of particle yield. It has been observed that v2 of particles composed of light quarks (i.e. up, down and strange) follow the same trends when scaled to the number of constituent quarks. Such observations implied that all light quarks gain the same flow in the heavy ion collision. On the other hand it was speculated that heavy quarks (charm and bottom) should have smaller v2 because of their in-medium energy losses. Due to their heavy mass, c quarks are produced mostly before QGP is formed, which makes them excellent probes to study this hot, dense and strongly interacting medium. The Solenoidal Tracker At RHIC (STAR) experiment took data with the newly installed Heavy Flavor Tracker (HFT) detector. Thanks to the state-of-the-art tracking resolution of the HFT it is possible to measure D0 mesons with unprecedented precision. This paper presents the STAR experiment measurement of D0 elliptic flow.

  4. Face au risque

    CERN Document Server

    Grosse, Christian; November, Valérie

    2007-01-01

    Ce volume collectif sur le risque inaugure la collection L'ÉQUINOXE. Ancré dans l'histoire pour mesurer les continuités et les ruptures, il illustre la manière dont les sciences humaines évaluent et mesurent les enjeux collectifs du risque sur les plans politiques, scientifiques, énergétiques, juridiques et éthiques. Puisse-t-il nourrir la réflexion sur la culture et la prévention du risque. Ses formes épidémiques, écologiques, sociales, terroristes et militaires nourrissent les peurs actuelles, structurent les projets sécuritaires et constituent - sans doute - les défis majeurs à notre modernité. Dans la foulée de la richesse scientifique d'Equinoxe, L'ÉQUINOXE hérite de son esprit en prenant à son tour le pari de contribuer - non sans risque - à enrichir en Suisse romande et ailleurs le champ éditorial des sciences humaines dont notre société a besoin pour forger ses repères. Après Face au risque suivra cet automne Du sens des Lumières. (MICHEL PORRET Professeur Ordinaire à la F...

  5. Di-jet Hadron Correlations in Central Au+Au Collisions at √{sNN} = 200 GeV at STAR

    Science.gov (United States)

    Elsey, Nicholas; STAR Collaboration

    2017-09-01

    Jets and their modifications due to partonic energy loss provide a powerful tool to study the properties of the QGP created in ultrarelativistic heavy-ion collisions. For jets reconstructed with the anti-kT algorithm with resolution parameter R = 0.4 , previous measurements of the di-jet asymmetry AJ at STAR) indicate that the observed imbalance of an initial ``hard-core'' di-jet selection with pTconst > 2.0 GeV/c, pTlead > 20.0 GeV/c and pTsub > 10.0 GeV/c is restored to the balance of the pp reference when soft constituents are included. The lost energy recovered with soft constituents suggests soft gluon radiation by high pT partons. Jet-hadron correlations with respect to di-jets allow a differential assessment of the kinematic properties of the soft gluon radiation spectrum induced by partonic energy loss in the QGP. We present charged hadron correlations with respect to the di-jets found in the above AJ analysis, and compare to similar measurements using a jet trigger at RHIC.

  6. Que faisons-nous au CERN ?

    CERN Multimedia

    1999-01-01

    Le CERN a pour vocation la science pure, l'étude des questions les plus fondamentales de la nature:Qu'est-ce que la matière ?D'ou vient-elle ? Comment s'agglomère-t-elle en formes complexes comme les étoiles, les planètes et les êtres humains ? Au CERN, les collisions de particules servent à sonder le coeur de la matière et les chercheurs du Laboratoire étudient ces millions de collisions de particules afin de trouver des réponses à ces questions.

  7. Rapidity and species dependence of particle production at largetransverse momentum for d+Au collisions at psNN = 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage,J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2006-12-19

    We determine rapidity asymmetry in the production of charged pions, protons and anti-protons for large transverse momentum (p{sub T}) for d+Au collisions at {radical}s{sub NN} = 200 GeV. The rapidity asymmetry is defined as the ratio of particle yields at backward rapidity (Au beam direction or -ve rapidity) to those at forward rapidity (d beam direction or +ve rapidity). The identified hadrons are measured in the rapidity regions |y| < 0.5 and 0.5 < |y| < 1.0 for the p{sub T} range 2.5 < p{sub T} < 10 GeV/c. We observe significant rapidity asymmetry for charged pion and proton+anti-proton production in both rapidity regions. The asymmetry is larger for 0.5 < |y| < 1.0 than for |y| < 0.5 and is almost independent of particle type. The measurements are compared to various model predictions employing multiple scattering, energy loss, nuclear shadowing, saturation effects, and recombination, and also to a phenomenological parton model. We find that asymmetries are sensitive to model parameters and show model-preference. The rapidity dependence of {pi}{sup -}/{pi}{sup +} and {bar p}/p ratios in peripheral d+Au and forward neutron-tagged events are used to study the contributions of valence quarks and gluons to particle production at high p{sub T}. The results are compared to calculations based on NLO pQCD and other measurements of quark fragmentation functions.

  8. The study of quasi-projectiles produced in Ni+Ni and Ni+Au collisions: excitation energy and spin; Etude des quasi-projectiles produits dans les collisions Ni+Ni et Ni+Au: energie d'excitation et spin

    Energy Technology Data Exchange (ETDEWEB)

    Buta, A

    2003-02-01

    During the collision between the projectile and the target nuclei in the intermediate energy regime (E < 100 MeV/nucleon) two excited nuclei are mainly observed in the exit channel, the quasi projectile (QP) and the quasi target. They disintegrate by particle emission. However, this binary picture is perturbed by the emission of particles and light fragments with velocities intermediate between the projectile velocity and the target one, all along the interaction (midrapidity component). This work aim to determine the excitation energy and the intrinsic angular momentum (or spin) of quasi-projectiles produced in the Ni+Ni and Ni+Au collisions at 52 and 90 MeV/nucleon. The excitation energy is deduced from the kinematical characteristics of particles emitted by the quasi-projectile. They have to be separated from midrapidity particles. Three different scenarios have been used for this purpose. The spin of the quasi-projectile has been extracted from the experimental data by mean of proton and alpha particles multiplicities emitted by the QP in the Ni+Au at 52 MeV/nucleon reaction. The results have been compared to the predictions of a theoretical model based on nucleon transfers. Their evolution is qualitatively reproduced as a function of the violence of the collision. (author)

  9. Borophene synthesis on Au(111)

    Science.gov (United States)

    Guisinger, Nathan; Kiraly, Brian; Zhang, Zhuhua; Mannix, Andrew; Hersam, Mark C.; Yakobson, Boris I.

    The recent experimental discovery of borophene, the metallic 2-dimensional allotrope of boron, has sparked tremendous interest in further exploration of this unique material. The initial synthesis of borophene was accomplished on Ag substrates and serves as a quintessential example of predictive modeling to experimental realization. In this talk, we expand the phase-space of borophene synthesis to Au. Borophene synthesis was accomplished by evaporating elemental boron onto a Au(111) substrate. The synthesized borophene retains its metallic character on Au as verified with scanning tunneling spectroscopy. Most fascinating is the difference in growth dynamics on the Au(111) substrate where the reconstructed surface presents a unique energy landscape for borophene nucleation and growth. We find that the initial low-coverage growth of borophene modifies the herringbone reconstruction into a ``trigonal'' network, where the 2D boron islands are uniformly templated across the surface. Increasing coverage results in the increasing size of the templated borophene islands until they coalesce into larger sheets. The observed growth dynamics are supported by the computational modeling of boron nucleation on Au.

  10. L’apprentissage au cern

    CERN Multimedia

    2007-01-01

    pour les professions d’électronicien(ne) et de laborantin(e) en physique L’apprentissage au CERN est régi par les lois, règlements et contrats en vigueur dans le canton de Genève. En cas de réussite à l’examen de fin d’apprentissage, les apprentis obtiennent le Certificat fédéral de capacité suisse (CFC). 6 places au total sont ouvertes au recrutement pour les deux professions. L’apprentissage dure 4 ans. Minima requis pour faire acte de candidature : avoir au moins 15 ans et moins de 21 ans à la date de début de l’apprentissage ; avoir terminé la scolarité obligatoire, au minimum 9e du Cycle d’orientation genevois (3e en France) ; être ressortissant d’un pays membre du CERN (Allemagne, Autriche, Belgique, Bulgarie, Danemark, Espagne, Finlande, France, Grèce, Hongrie, Italie, Norvège, Pays-Bas, Pologne, Portugal, Royaume-Uni, République tchèque, République slovaque , Suède, Suisse) ; pour les résidents en Suisse : être ressortissant su...

  11. Transverse Momentum Spectra of KS0 and K*0 at Midrapidity in d + Au, Cu + Cu, and p+p Collisions at sNN=200 GeV

    Directory of Open Access Journals (Sweden)

    Bao-Chun Li

    2015-01-01

    Full Text Available We analyze transverse momentum spectra of KS0 and K*0 at midrapidity in d + Au, Cu + Cu, and p+p collisions at sNN=200 GeV in the formworks of Tsallis statistics and Boltzmann statistics, respectively. Both of them can describe the transverse momentum spectra and extract the thermodynamics parameters of matter evolution in the collisions. The parameters are helpful for us to understand the thermodynamics factors of the particle production.

  12. Modification of the rho-meson detected by low-mass electron-positron pairs in central Pb-Au collisions at 158 A GeV/c

    CERN Document Server

    Adamová, D; Appelshäuser, H; Belaga, V; Bielcikova, J; Braun-munziger, P; Busch, O; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Zeev; Garabatos, C; Glssel, P; Holeczek, J; Kushpil, V; Ludolphs, a W; Maas, A; Marn, A; Miloevi, J; Milov, A; Mikowiec, D; Panebrattsev, iscs Yu; Petchenova, O; Petrek, V; Pfeiffer, A; Rak, J; Ravinovich, acI; Sako, H; Schmitz, W; Sedykh, S; Shimansky, S; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Wessels, J P; Wienold, T; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2008-01-01

    We present a measurement of $e^+e^-$ pair production in central Pb-Au collisions at 158$A$ GeV/$c$. As reported earlier, a significant excess of the $e^+e^-$ pair yield over the expectation from hadron decays is observed. The improved mass resolution of the present data set, recorded with the upgraded CERES experiment at the CERN-SPS, allows for a comparison of the data with different theoretical approaches. The data clearly favor a substantial in-medium broadening of the $\\rho$ spectral function over a density-dependent shift of the $\\rho$ pole mass at SPS energy. The in-medium broadening model implies that baryon induced interactions are the key mechanism to in-medium modifications of the $\\rho$-meson in the hot fireball.

  13. Multiscale Modeling of Au-Island Ripening on Au(100

    Directory of Open Access Journals (Sweden)

    Karin Kleiner

    2011-01-01

    Full Text Available We describe a multiscale modeling hierarchy for the particular case of Au-island ripening on Au(100. Starting at the microscopic scale, density functional theory was used to investigate a limited number of self-diffusion processes on perfect and imperfect Au(100 surfaces. The obtained structural and energetic information served as basis for optimizing a reactive forcefield (here ReaxFF, which afterwards was used to address the mesoscopic scale. Reactive force field simulations were performed to investigate more diffusion possibilities at a lower computational cost but with similar accuracy. Finally, we reached the macroscale by means of kinetic Monte Carlo (kMC simulations. The reaction rates for the reaction process database used in the kMC simulations were generated using the reactive force field. Using this strategy, we simulated nucleation, aggregation, and fluctuation processes for monoatomic high islands on Au(100 and modeled their equilibrium shape structures. Finally, by calculating the step line tension at different temperatures, we were able to make a direct comparison with available experimental data.

  14. Study of charge correlation for Z {<=} 2 obtained in Au+Au collisions with incident energy from 150 up to 400 MeV/A. FOPI detector is used; Etude des correlations des charges Z {<=} 2 obtenues lors des collisions Au+Au aux energies incidentes de 150 a 400 MeV/A avec le detecteur fopi

    Energy Technology Data Exchange (ETDEWEB)

    Pras, Ph

    1997-01-24

    In the first part of this work we present what information can be driven from heavy ion collision studies and what can be expected from the state equation of nuclear matter. We introduce the notion of centrality and the concept of spectator-participant. The different models of collisions are reviewed. The theory of correlations between light particles is used as a tool to predict some results about the shape and population density of theoretical spectra.The Coulomb model which implies a thermal interpretation of heavy ion collisions is modified in order to take excited states into account and to reproduce the collective phenomena of flow and squeeze-out. Within the frame of this modified Coulomb model 3 notions of nuclear temperature are compared. A discussion is lead to find out the temperature of nuclear matter at the very moment of fragmentation. (A.C.) 134 refs.

  15. Measurement of $K_S^0$ and $K^{*0}$ in $p$$+$$p$, $d$$+$Au, and Cu$+$Cu collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Black, D; Blau, D S; Boissevain, J G; Bok, J; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, S; Caringi, A; Chang, B S; Charvet, J -L; Chen, C -H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; del Valle, Z Conesa; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Ding, L; Dion, A; Do, J H; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; D'Orazio, L; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Grim, G; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guragain, H; Gustafsson, H -Å; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Han, S Y; Hanks, J; Harada, H; Hartouni, E P; Haruna, K; Hasegawa, S; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Hoshino, T; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; Johnson, B M; Jones, T; Joo, E; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kaneta, M; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kihara, K; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, H -J; Kim, M; Kim, Y -J; Kim, Y K; Kinney, E; Kiss, Á; Kistenev, E; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Kofarago, M; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S H; Lee, T; Leitch, M J; Leite, M A L; Leitgab, M; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, A J; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Norman, B E; Nouicer, R; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Koop, J D Orjuela; Oskarsson, A; Ouchida, M; Ozaki, H; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Riveli, N; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, V; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shevel, A; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, D; Thomas, T L; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Torii, H; Towell, M; Towell, R; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; Whitaker, S; White, S N; Winter, D; Wolin, S; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Yoon, I; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimányi, J; Zolin, L

    2014-01-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of $K_S^0$ and $K^{*0}$ meson production at midrapidity in $p$$+$$p$, $d$$+$Au, and Cu$+$Cu collisions at $\\sqrt{s_{_{NN}}}=200$ GeV. The $K_S^0$ and $K^{*0}$ mesons are reconstructed via their $K_S^0 \\rightarrow \\pi^0(\\rightarrow \\gamma\\gamma)\\pi^0(\\rightarrow\\gamma\\gamma)$ and $K^{*0} \\rightarrow K^{\\pm}\\pi^{\\mp}$ decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of $K_S^0$ and $K^{*0}$ mesons in $d$$+$Au and Cu$+$Cu collisions at different centralities. In the $d$$+$Au collisions, the nuclear modification factor of $K_S^0$ and $K^{*0}$ mesons is almost constant as a function of transverse momentum and is consistent with unity showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu$+$Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In c...

  16. Au36(SPh)23 nanomolecules.

    Science.gov (United States)

    Nimmala, Praneeth Reddy; Dass, Amala

    2011-06-22

    A new core size protected completely by an aromatic thiol, Au(36)(SPh)(23), is synthesized and characterized by MALDI-TOF mass spectrometry and UV-visible spectroscopy. The synthesis involving core size changes is studied by MS, and the complete ligand coverage by aromatic thiol group is shown by NMR.

  17. Measurement of $\\pi^{0}$ and $\\gamma$ in d+Au collisions at $\\sqrt{s_{NN}}=$ 200 GeV by PHENIX experiment

    CERN Document Server

    Chvala, Ondrej

    2009-01-01

    Previous results indicated that high $p_T$ particle suppression in Au+Au interactions is a final state effect, since R$_{dA}$ ratios were compatible with unity, albeit within large experimental errors. It is important to test this conclusion to higher precision since the modification of structure functions may be involved. Recent d+Au data taken in 2008 improve the integrated luminosity by about a factor of thirty compared to the 2003 data. A more precise measurement of both $\\pi^0$ and $\\gamma$ at higher $p_T$ will shed new light on whether the initial state in the heavy nuclei is modified.

  18. Triangular flow of negative pions emitted in PbAu collisions at √{sNN} = 17.3 GeV

    Science.gov (United States)

    Adamová, D.; Agakichiev, G.; Andronic, A.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielčíková, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Hering, G.; Holeczek, J.; Kalisky, M.; Karpenko, Iu.; Krobath, G.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Miśkowiec, D.; Panebrattsev, Y.; Petchenova, O.; Petráček, V.; Radomski, S.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Schuchmann, S.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Tsiledakis, G.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Yurevich, S.; Yurevich, V.

    2017-01-01

    Differential triangular flow, v3 (pT), of negative pions is measured at √{sNN} = 17.3 GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30% with a mean centrality of 5.5%. This is the first measurement as a function of transverse momentum of the triangular flow at SPS energies. The pT range extends from about 0.05 GeV/c to more than 2 GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydrodynamic calculation combined with an UrQMD cascade model for the late stages.

  19. Probing the quenching of CdSe/ZnS qdots by Au, Au/Ag, and Au/Pd nanoparticles.

    Science.gov (United States)

    Han, Hyunjoo; Valle, Valerie; Maye, Mathew M

    2012-11-02

    The resonance energy transfer between CdSe/ZnS quantum dots (qdots) and three metallic nanoparticles (NPs) with different surface plasmon resonance (SPR) characteristics were studied. Gold, gold/silver and gold/palladium NPs were used as energy acceptors for qdots with donor emission at 570 nm. Due to the different spectral overlaps between the SPR signatures and qdot emission, varied energy transfer characteristics were observed. The energy transfer was quantified via the Stern-Volmer relationship, since in this study the energy transfer was collision based. The Au/Ag and Au/Pd NPs in particular showed high K(SV) values, while the Au NPs showed much lower energy transfer efficiency. Since the NPs used in this study were relatively large (d ~ 15-20 nm), the experimental system was also influenced by the NP extinction coefficients of ≈10(8) M(-1) cm(-1). To address this potential inner filter effect, the quenching profiles were normalized by SPR transmittance. The results are important to the field, as many of these classes of nanomaterials are being employed in energy transfer based studies, as well as in colorimetric sensing.

  20. Study of the production of J/{psi} in Au-Au collisions at 200 GeV per nucleon pair in the PHENIX experiment; Etude de la production du J/{psi} dans les collisions or-or a 200 GeV par paire de nucleons dans l'experience PHENIX

    Energy Technology Data Exchange (ETDEWEB)

    Tram, V.N

    2006-01-15

    One of the most promising signature of Quark Gluon Plasma formation is the heavy quarkonium suppression due to color screening effect. First experiments at the SPS (CERN) have measured an 'anomalous suppression' of the J/{psi} yields (cc-bar state) in central Pb+Pb collisions. However, measurements at different collision energies and with different ions are mandatory to conclude about the discovery of a new state of nuclear matter. This thesis describes the J/{psi} production measured in the dimuon decay channel by the PHENIX experiment (RHIC) studying Au+Au collisions at 200 GeV in the center of mass. The J/{psi} yield measured in the most central collisions is suppressed by a factor of 3 as compared to the yield expected assuming binary scaling. Within the error bars, the suppression does not affect the J/{psi}'s rapidity distribution. However, a broadening of the transverse momentum distribution is observed as compared to the distribution measured in p+p collisions. In order to understand this suppression, 'cold nuclear effects', namely nuclear absorption and shadowing, are to be taken into account. These effects can describe neither the suppression amplitude nor the suppression pattern, suggesting that other mechanisms are involved. Predictions from different models which reproduce the suppression observed by NA50, can hardly describe the PHENIX measurements and over-estimate the suppression at RHIC. Comparisons with predictions from models including recombination of charm quarks give a reasonable description of the suppression amplitude as a function of centrality. However, these predictions are not in good agreement with the observed rapidity and transverse momentum distributions. Finally, one possible scenario is that the temperature at RHIC is not high enough to reach direct J/{psi} melting and that the measured suppression is due to the sequential disappearance from higher mass resonances ({chi}{sub c} and {psi}'). In this

  1. Decay spectroscopy of $^{178}$Au

    CERN Document Server

    Whitmore, B

    In this thesis, the neutron-deficient nucleus $^{178}$Au is investigated through decay spectroscopy. Si and HPGe detectors were used to analyse the decay radiation of $^{178}$Au and its daughter nuclei. Previous studies have been unable to distinguish decay radiation from different isomeric states of this nucleus. This thesis represents the first time such isomeric discrimination has been achieved, and presents tentative spin assignments of both the ground state and an isomer. The neutron-deficient gold isotopes are an area of interest for the study of shape coexistence. This is the phenomenon exhibited by nuclei able to exist at a number of close lying energy minima, each reflecting a distinct type of deformation. It is hoped that studies such as this can help identify the evolution of nuclear deformation in this region of the nuclear chart.

  2. Le CRDI au Costa Rica

    International Development Research Centre (IDRC) Digital Library (Canada)

    La stabilité politique du Costa Rica a fait de ce pays un partenaire essen- tiel du CRDI en Amérique centrale pour la recherche portant sur l'agriculture, les politiques économiques, la démocratisation et la prévention des catastrophes naturelles. Le CRDI a beaucoup contribué à la recherche en agriculture au Costa Rica,.

  3. Cas de Cotonou au Benin

    African Journals Online (AJOL)

    Au nombre de ces nuisances, figurent entre autres, la perte de temps et par ricochet d'importantes recettes .... La méthodologie utilisée est basée sur deux types d'approches : l'approche théorique et celle empirique. Le premier volet de ...... Université de Bordeaux Talence, 456 pages. SEGBEDJI, E. (2001) : Impact du trafic ...

  4. Measurement of the relative yields of $\\psi(2S)$ to $\\psi(1S)$ mesons produced at forward and backward rapidity in $p$$+$$p$, $p$$+$Al, $p$$+$Au, and $^{3}$He$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV

    CERN Document Server

    Adare, A; Ajitanand, N N; Akiba, Y; Alfred, M; Andrieux, V; Aoki, K; Apadula, N; Asano, H; Ayuso, C; Azmoun, B; Babintsev, V; Bai, M; Bandara, N S; Bannier, B; Barish, K N; Bathe, S; Bazilevsky, A; Beaumier, M; Beckman, S; Belmont, R; Berdnikov, A; Berdnikov, Y; Blau, D S; Boer, M; Bok, J S; Bownes, E K; Boyle, K; Brooks, M L; Bryslawskyj, J; Bumazhnov, V; Butler, C; Campbell, S; CanoaRoman, C; Cervantes, R; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Chujo, T; Citron, Z; Connors, M; Cronin, N; Csanád, M; Csörgő, T; Danley, T W; Datta, A; Daugherity, M S; David, G; DeBlasio, K; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Dion, A; Diss, P B; Dixit, D; Do, J H; Drees, A; Drees, K A; Dumancic, M; Durham, J M; Durum, A; Dusing, J P; Elder, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fan, W; Feege, N; Fields, D E; Finger, M; Finger, M; Jr., \\,; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukuda, Y; Gal, C; Gallus, P; Garg, P; Ge, H; Giordano, F; Glenn, A; Goto, Y; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Guragain, H; Hachiya, T; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamilton, H F; Han, S Y; Hanks, J; Hasegawa, S; Haseler, T O S; Hashimoto, K; He, X; Hemmick, T K; Hill, J C; Hill, K; Hollis, R S; Homma, K; Hong, B; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Imai, K; Inaba, M; Iordanova, A; Isenhower, D; Ito, Y; Ivanishchev, D; Jacak, B V; Jezghani, M; Ji, Z; Jia, J; Jiang, X; Johnson, B M; Jorjadze, V; Jouan, D; Jumper, D S; Kanda, S; Kang, J H; Kapukchyan, D; Karthas, E; Kawall, D; Kazantsev, A V; Key, J A; Khachatryan, V; Khanzadeev, A; Kim, C; Kim, D J; Kim, E -J; Kim, G W; Kim, M; Kimball, M L; Kimelman, B; Kincses, D; Kistenev, E; Kitamura, R; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Komkov, B; Kotler, J R; Kotov, D; Kudo, S; Kurita, K; Kurosawa, M; Kwon, Y; Lacey, R; Lajoie, J G; Lallow, E O; Lebedev, A; Lee, S; Lee, S H; Leitch, M J; Leung, Y H; Lewis, N A; Li, X; Lim, S H; Liu, L D; Liu, M X; Loggins, V-R; Loggins, V -R; Lovasz, K; Lynch, D; Majoros, T; Makdisi, Y I; Makek, M; Malaev, M; Manion, A; Manko, V I; Mannel, E; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendez, A R; Mendoza, M; Mignerey, A C; Mihalik, D E M; Milov, A; Mishra, D K; Mitchell, J T; Mitsuka, G; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, T; Morrison, D P; Morrow, S I M; Moukhanova, T V; Murakami, T; Murata, J; Mwai, A; Nagai, K; Nagashima, K; Nagashima, T; Nagle, J L; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakano, K; Nattrass, C; Netrakanti, P K; Niida, T; Nishimura, S; Nouicer, R; Novák, T; Novitzky, N; Novotny, R; Nyanin, A S; O'Brien, E; Ogilvie, C A; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ottino, G J; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, J S; Park, S; Pate, S F; Patel, M; Peng, J -C; Peng, W; Perepelitsa, D V; Perera, G D N; Peressounko, D Yu; PerezLara, C E; Perry, J; Petti, R; Phipps, M; Pinkenburg, C; Pinson, R; Pisani, R P; Press, C J; Pun, A; Purschke, M L; Rak, J; Ramson, B J; Ravinovich, I; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Richford, D; Rinn, T; Rolnick, S D; Rosati, M; Rowan, Z; Rubin, J G; Runchey, J; Safonov, A S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, K; Sato, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seidl, R; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shioya, T; Shukla, P; Sickles, A; Silva, C L; Silva, J A; Silvermyr, D; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Smith, K L; Snowball, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Stankus, P W; Stepanov, M; Stien, H; Stoll, S P; Sugitate, T; Sukhanov, A; Sumita, T; Sun, J; Syed, SS; Sziklai, J; Takeda, A; Taketani, A; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarnai, G; Tieulent, R; Timilsina, A; Todoroki, T; Tomášek, M; Towell, C L; Towell, R; Towell, R S; Tserruya, I; Ueda, Y; Ujvari, B; van Hecke, H W; Velkovska, J; Virius, M; Vrba, V; Vukman, N; Wang, X R; Wang, Z; Watanabe, Y; Watanabe, Y S; Wei, F; White, A S; Wong, C P; Woody, C L; Wysocki, M; Xia, B; Xu, C; Xu, Q; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamamoto, H; Yanovich, A; Yoo, J H; Yoon, I; Yu, H; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S; Zou, L

    2016-01-01

    The PHENIX Collaboration has measured the ratio of the yields of $\\psi(2S)$ to $\\psi(1S)$ mesons produced in $p$$+$$p$, $p$$+$Al, $p$$+$Au, and $^{3}$He$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$ GeV over the forward and backward rapidity intervals $1.2<|y|<2.2$. We find that the ratio in $p$$+$$p$ collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward ($p$-going or $^{3}$He-going) direction, the relative yield of $\\psi(2S)$ mesons to $\\psi(1S)$ mesons is consistent with the value measured in \\pp collisions. However, in the backward (nucleus-going) direction, the $\\psi(2S)$ is preferentially suppressed by a factor of $\\sim$2. This suppression is attributed in some models to breakup of the weakly-bound $\\psi(2S)$ through final state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequen...

  5. Measurement of the relative yields of ψ (2 S ) to ψ (1 S ) mesons produced at forward and backward rapidity in p +p , p +Al , p +Au , and 3He+Au collisions at √{sNN}=200 GeV

    Science.gov (United States)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Alfred, M.; Andrieux, V.; Aoki, K.; Apadula, N.; Asano, H.; Ayuso, C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bathe, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J. S.; Bownes, E. K.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Bumazhnov, V.; Butler, C.; Campbell, S.; Canoa Roman, V.; Cervantes, R.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Chujo, T.; Citron, Z.; Connors, M.; Cronin, N.; Csanád, M.; Csörgő, T.; Danley, T. W.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dion, A.; Diss, P. B.; Dixit, D.; Do, J. H.; Drees, A.; Drees, K. A.; Dumancic, M.; Durham, J. M.; Durum, A.; Dusing, J. P.; Elder, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fan, W.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukuda, Y.; Gal, C.; Gallus, P.; Garg, P.; Ge, H.; Giordano, F.; Glenn, A.; Goto, Y.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; He, X.; Hemmick, T. K.; Hill, J. C.; Hill, K.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ito, Y.; Ivanishchev, D.; Jacak, B. V.; Jezghani, M.; Ji, Z.; Jia, J.; Jiang, X.; Johnson, B. M.; Jorjadze, V.; Jouan, D.; Jumper, D. S.; Kanda, S.; Kang, J. H.; Kapukchyan, D.; Karthas, S.; Kawall, D.; Kazantsev, A. V.; Key, J. A.; Khachatryan, V.; Khanzadeev, A.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, G. W.; Kim, M.; Kimball, M. L.; Kimelman, B.; Kincses, D.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Komkov, B.; Kotler, J. R.; Kotov, D.; Kudo, S.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Lacey, R.; Lajoie, J. G.; Lallow, E. O.; Lebedev, A.; Lee, S.; Lee, S. H.; Leitch, M. J.; Leung, Y. H.; Lewis, N. A.; Li, X.; Li, X.; Lim, S. H.; Liu, L. D.; Liu, M. X.; Loggins, V.-R.; Loggins, V.-R.; Lovasz, K.; Lynch, D.; Majoros, T.; Makdisi, Y. I.; Makek, M.; Malaev, M.; Manion, A.; Manko, V. I.; Mannel, E.; Masuda, H.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendez, A. R.; Mendoza, M.; Mignerey, A. C.; Mihalik, D. E.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Mitsuka, G.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, T.; Morrison, D. P.; Morrow, S. I. M.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagai, K.; Nagashima, K.; Nagashima, T.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Novotny, R.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ottino, G. J.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, J. S.; Park, S.; Pate, S. F.; Patel, M.; Peng, J.-C.; Peng, W.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perezlara, C. E.; Perry, J.; Petti, R.; Phipps, M.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Press, C. J.; Pun, A.; Purschke, M. L.; Rak, J.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richford, D.; Rinn, T.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Runchey, J.; Safonov, A. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, K.; Sato, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shioya, T.; Shukla, P.; Sickles, A.; Silva, C. L.; Silva, J. A.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Smith, K. L.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stepanov, M.; Stien, H.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Syed, S.; Sziklai, J.; Takeda, A.; Taketani, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarnai, G.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Towell, C. L.; Towell, R.; Towell, R. S.; Tserruya, I.; Ueda, Y.; Ujvari, B.; van Hecke, H. W.; Vazquez-Carson, S.; Velkovska, J.; Virius, M.; Vrba, V.; Vukman, N.; Wang, X. R.; Wang, Z.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; White, A. S.; Wong, C. P.; Woody, C. L.; Wysocki, M.; Xia, B.; Xu, C.; Xu, Q.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamamoto, H.; Yanovich, A.; Yin, P.; Yoo, J. H.; Yoon, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zharko, S.; Zhou, S.; Zou, L.; Phenix Collaboration

    2017-03-01

    The PHENIX Collaboration has measured the ratio of the yields of ψ (2 S ) to ψ (1 S ) mesons produced in p +p , p +Al , p +Au , and 3He+Au collisions at √{s NN}=200 GeV over the forward and backward rapidity intervals 1.2 <|y |<2.2 . We find that the ratio in p +p collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward (p -going or 3He-going) direction, the relative yield of ψ (2 S ) mesons to ψ (1 S ) mesons is consistent with the value measured in p +p collisions. However, in the backward (nucleus-going) direction, the ψ (2 S ) meson is preferentially suppressed by a factor of ˜2 . This suppression is attributed in some models to the breakup of the weakly bound ψ (2 S ) meson through final-state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states.

  6. L’apprentissage au CERN

    CERN Multimedia

    Staff Association

    2016-01-01

    En 1961, sur la base du constat que l’évolution du marché du travail nécessitait un besoin croissant de personnel qualifié, le 1er accord entre la République et canton de Genève et le CERN fut signé. Cet accord avait notamment pour objet la formation professionnelle de jeunes électroniciens et techniciens de laboratoires en physique. Le CERN, acteur local économique d’importance, soulignait par cet accord sa volonté de participer au développement économique et social local. Le 1er apprenti arriva au CERN en 1965. En 1971, le centre d’apprentissage fut créé ; il accueille aujourd’hui plus d’une vingtaine d’apprentis au total, à raison d’environ six nouveaux apprentis chaque année. Cet apprentissage est dédié aux jeunes âgés e...

  7. Fabricating a Homogeneously Alloyed AuAg Shell on Au Nanorods to Achieve Strong, Stable, and Tunable Surface Plasmon Resonances

    KAUST Repository

    Huang, Jianfeng

    2015-08-13

    Colloidal metal nanocrystals with strong, stable, and tunable localized surface plasmon resonances (SPRs) can be useful in a corrosive environment for many applications including field-enhanced spectroscopies, plasmon-mediated catalysis, etc. Here, a new synthetic strategy is reported that enables the epitaxial growth of a homogeneously alloyed AuAg shell on Au nanorod seeds, circumventing the phase segregation of Au and Ag encountered in conventional synthesis. The resulting core–shell structured bimetallic nanorods (AuNR@AuAg) have well-mixed Au and Ag atoms in their shell without discernible domains. This degree of mixing allows AuNR@AuAg to combine the high stability of Au with the superior plasmonic activity of Ag, thus outperforming seemingly similar nanostructures with monometallic shells (e.g., Ag-coated Au NRs (AuNR@Ag) and Au-coated Au NRs (AuNR@Au)). AuNR@AuAg is comparable to AuNR@Ag in plasmonic activity, but that it is markedly more stable toward oxidative treatment. Specifically, AuNR@AuAg and AuNR@Ag exhibit similarly strong signals in surface-enhanced Raman spectroscopy that are some 30-fold higher than that of AuNR@Au. When incubated with a H2O2 solution (0.5 m), the plasmonic activity of AuNR@Ag immediately and severely decayed, whereas AuNR@AuAg retained its activity intact. Moreover, the longitudinal SPR frequency of AuNR@AuAg can be tuned throughout the red wavelengths (≈620–690 nm) by controlling the thickness of the AuAg alloy shell. The synthetic strategy is versatile to fabricate AuAg alloyed shells on different shaped Au, with prospects for new possibilities in the synthesis and application of plasmonic nanocrystals.

  8. Preliminary results from the 2000 run of CERES on low-mass $e^{+}e^{-}}$ pair production in Pb-Au collisions at 158 A GeV

    CERN Document Server

    Cherlin, A

    2004-01-01

    CERES has measured low-mass e/sup positive /sup negative pairs in Pb- Au collisions at 158 A GeV in the year 2000 Pb run at the SPS with the goal of shedding more light on the origin of the previously observed low-mass pair enhancement. The spectrometer was upgraded with a radial TPC to improve the mass resolution. A very effective rejection of the combinatorial background is achieved using the combined information of the two RICH detectors, the dE/dx signal of the doublet of silicon drift chambers, and the TPC track dE/dx information. Various steps and the current status of the data analysis are presented. Corrigendum. Table 1 and figures 3 and 4, as originally published, represent an earlier version of the data analysis. The corrected table and figures have been published as a Corrigendum (see below). The Corrigendum has also been appended at the end of the PDF file linked to this page.

  9. PHENIX results on jets in d + Au

    Energy Technology Data Exchange (ETDEWEB)

    Hanks, J. Ali

    2016-12-15

    We present recently published results [A. Adare, et al., (arXiv:1509.04657)] on fully reconstructed R=0.3 anti-k{sub t} jets measured in p+p and d+Au collisions at 200 GeV center-of-mass energy. The jet yields for four centrality classes along with the p+p reference are presented, as well as both the minimum bias R{sub dAu} and centrality dependent R{sub dAu} and R{sub CP}. We find that while the minimum bias R{sub dA} is consistent with unity, providing a strong constraint on models including cold-nuclear-matter effects or energy loss in small systems, the centrality dependent R{sub dAu} show a striking variation which presents a challenge to models attempting to describe the interplay between soft and hard processes in these systems.

  10. Transport characteristics in Au/pentacene/Au diodes

    Science.gov (United States)

    Hayashi, Toshiaki; Naka, Akiyoshi; Hiroki, Masanobu; Yokota, Tomoyuki; Someya, Takao; Fujiwara, Akira

    2018-03-01

    We have used scanning and transmission electron microscopes (SEM and TEM) to study the structure of a pentacene thin film grown on a Au layer with and shown that it consists of randomly oriented amorphous pentacene clusters. We have also investigated the transport properties of amorphous pentacene in a metal–semiconductor–metal (MSM) diode structure and shown that the current is logarithmically proportional to the square root of the applied voltage, which indicates that transport occurs as the result of hopping between localized sites randomly distributed in space and energy.

  11. Acces au traitement anticancereux au Togo (access to treatment of ...

    African Journals Online (AJOL)

    Contexte : Au Togo, l'incidence et la mortalité des cancers ne cessent de croître en raison du diagnostic et de la prise en charge tardifs. D'autres raisons telles que l'absence d'oncologue spécialiste et la faible accessibilité aux médicaments anticancéreux sont de plus en plus évoquées. L'objectif de cette étude était de ...

  12. Au38(SPh)24: Au38 Protected with Aromatic Thiolate Ligands.

    Science.gov (United States)

    Rambukwella, Milan; Burrage, Shayna; Neubrander, Marie; Baseggio, Oscar; Aprà, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

    2017-04-06

    Au38(SR)24 is one of the most extensively investigated gold nanomolecules along with Au25(SR)18 and Au144(SR)60. However, so far it has only been prepared using aliphatic-like ligands, where R = -SC6H13, -SC12H25 and -SCH2CH2Ph. Au38(SCH2CH2Ph)24 when reacted with HSPh undergoes core-size conversion to Au36(SPh)24, and existing literature suggests that Au38(SPh)24 cannot be synthesized. Here, contrary to prevailing knowledge, we demonstrate that Au38(SPh)24 can be prepared if the ligand exchanged conditions are optimized, under delicate conditions, without any formation of Au36(SPh)24. Conclusive evidence is presented in the form of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), electrospray ionization mass spectra (ESI-MS) characterization, and optical spectra of Au38(SPh)24 in a solid glass form showing distinct differences from that of Au38(S-aliphatic)24. Theoretical analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au38(SPh)24 is not negligible with respect to that of its aliphatic analogous, and contains a significant component of ligand-ligand attractive interactions. Thus, while Au38(SPh)24 is stable at RT, it converts to Au36(SPh)24 either on prolonged etching (longer than 2 hours) at RT or when etched at 80 °C.

  13. Dielectron azimuthal anisotropy at mid-rapidity in Au + Au collisions at sNN=200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2014-12-01

    We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from √sNN=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Mee<1.1 GeV/c2 the dielectron v2 measurements are found to be consistent with expectations from π0,η,ω, and Φ decay contributions. In the mass region 1.1

  14. Genre et migration au Maroc

    OpenAIRE

    KHACHANI, Mohamed

    2011-01-01

    Euro-Mediterranean Consortium for Applied Research on International Migration (CARIM) Une des principales caractéristiques récentes de la migration marocaine est sa tendance à une féminisation soutenue. Le projet migratoire - qui était un projet d’hommes - intéresse de plus en plus les femmes marocaines au point de constituer actuellement près de la moitié de l’effectif migratoire marocain. Cette reconnaissance de l'importance des femmes dans la construction de l'espace migratoire a placé ...

  15. Genre et migration au Liban

    OpenAIRE

    JOUNI, Hassan

    2011-01-01

    Euro-Mediterranean Consortium for Applied Research on International Migration (CARIM) La femme possède un statut bien avancé au sein de la société libanaise : la Constitution libanaise proclame l’égalité entre les citoyens. Quelques lois et pratiques restent, toutefois, discriminatoires à l’égard de la femme, notamment la loi sur la nationalité et la loi sur le statut personnel. Une discrimination sociale très grave existe en ce qui concerne les femmes travaillant à domicile; elles subi...

  16. Nuclear Data Sheets for 181Au

    Science.gov (United States)

    Baglin, Coral M.

    1999-06-01

    Nuclear structure data pertaining to 181Au have been compiled and evaluated, and incorporated into the ENSDF data file. This evaluation of 181Au supersedes the previous publication (R. B. Firestone, Nuclear Data Sheets 62, 101 (1991) (literature cutoff date October 1990)), and includes literature available by 2 July 1999. The newly incorporated references are: 1999Mu05, 1999So01, 1995Au04, 1995Bi01, 1991Ry01, 1979Ha10, 1970Ha18.

  17. Nuclear data sheets for 181Au

    Energy Technology Data Exchange (ETDEWEB)

    Baglin, Coral M.

    1999-07-02

    Nuclear structure data pertaining to 181Au have been compiled and evaluated, and incorporated into the ENSDF data file. This evaluation of 181Au supersedes the previous publication (R. B. Firestone, Nuclear Data Sheets 62, 101 (1991) (literature cutoff date October 1990)), and includes literature available by 2 July 1999. The newly incorporated references are: 1999Mu05, 1999So01, 1995Au04, 1995Bi01, 1991Ry01, 1979Ha10, 1970Ha18.

  18. Predicted Habitat Suitability for Montipora Corals in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This raster denotes predicted habitat suitability for Montipora in the Au'au Channel region. Maximum Entropy (MaxEnt) modeling software was used to create this...

  19. Predicted Habitat Suitability for Porites in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This raster denotes predicted habitat suitability for Porites in the Au'au Channel region. Maximum Entropy (MaxEnt) modeling software was used to create this...

  20. Predicted Habitat Suitability for Porites Corals in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This raster denotes predicted habitat suitability for Porites in the Au'au Channel region. Maximum Entropy (MaxEnt) modeling software was used to create this...

  1. Predicted Habitat Suitability for Leptoseris Corals in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This raster denotes predicted habitat suitability for Leptoseris in the Au'au Channel region. Maximum Entropy (MaxEnt) modeling software was used to create this...

  2. Predicted Habitat Suitability for All Mesophotic Corals in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This raster denotes predicted habitat suitability for all mesophotic corals in the Au'au Channel region. Maximum Entropy (MaxEnt) modeling software was used to...

  3. Predicted Habitat Suitability for Leptoseris in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This raster denotes predicted habitat suitability for Leptoseris in the Au'au Channel region. Maximum Entropy (MaxEnt) modeling software was used to create this...

  4. Predicted Habitat Suitability for All Mesophotic Corals in the Au'au Channel Region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is located between the islands of Maui, Lanai, Molokai and Kahoolawe, and includes the Au'au Channel as well as parts of the Kealaikahiki, Alalakeiki...

  5. ΛΛ Correlation Function in Au+Au Collisions at sNN=200GeV

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L. -X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2015-01-12

    We present Lambda Lambda correlation measurements in heavy-ion collisions for Au + Au collisions at root s(NN) = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednicky-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the Lambda Lambda correlation function and interaction parameters for dihyperon searches are discussed.

  6. Comparative study of anchoring groups for molecular electronics: structure and conductance of Au-S-Au and Au-NH{sub 2}-Au junctions

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, I S; Mowbray, D J; Thygesen, K S; Jacobsen, K W [Center for Atomic-scale Materials Design (CAMD), Department of Physics, Building 307, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark)

    2008-09-17

    The electrical properties of single-molecule junctions, consisting of an organic molecule coupled to metal electrodes, are sensitive to the detailed atomic structure of the molecule-metal contact. This, in turn, is determined by the anchoring group linking the molecule to the metal. With the aim of identifying and comparing the intrinsic properties of two commonly used anchoring groups, namely thiol and amine groups, we have calculated the atomic structure and conductance traces of different Au-S-Au and Au-NH{sub 2}-Au nanojunctions using density functional theory (DFT). Whereas NH{sub 2} shows a strong structural selectivity towards atop-gold configurations, S shows large variability in its bonding geometries. As a result, the conductance of the Au-NH{sub 2}-Au junction is less sensitive to the structure of the gold contacts than the Au-S-Au junction. These findings support recent experiments which show that amine-bonded molecules exhibit more well-defined conductance properties than do thiol-bonded molecules.

  7. Travailler avec Windows 7 au CERN (FR)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    Vue d'ensemble des nouveaux concepts et des changements dans l'interface utilisateur survenus dans Windows 7 depuis les versions antérieures de Windows (XP ou Vista). La mise à disposition de Windows 7 au CERN et son intégration dans l’infrastructure de Windows au CERN seront présentées.

  8. English for au pairs the au pair's guide to learning English

    CERN Document Server

    Curtis, Lucy

    2014-01-01

    English for Au Pairs has interlinked stories about a group of au pairs new to England. Marta, an 18-year-old from Poland arrives in the UK to work as an au pair. Throughout her year-long stay she has many different experiences - some bad, some good - but with the support of her host family she finds new friends and improves her English. English for Au Pairs offers insight into the joys and difficulties of being an au pair while at the same time reinforcing English language learning through grammar explanations and exercises.

  9. Au microstructure and the functional properties of Ni/Au finishes on ceramic IC packages

    Energy Technology Data Exchange (ETDEWEB)

    Winters, E.D.; Baxter, W.K. [Coors Electronic Package Co., Chattanooga, TN (United States); Braski, D.N.; Watkins, T.R. [Oak Ridge National Lab., TN (United States)

    1995-12-31

    Ni/Au plated finishes used on thick-film metallized multilayer ceramic packages for integrated circuits must meet functional requirements such as bondability, sealability, and solderability. Their ability to do so is dependent, among other things, on the ability of the Au deposit to inhibit the grain boundary diffusion and subsequent surface oxidation of Ni. In this study, the relation between functional performance, Ni diffusionr ate, and Au microstructure was examined. Extent of Ni diffusion during heating was determined by Auger electron spectroscopy for several electrolytic and electroless Ni/Au finishing processes. Results were correlated with differences in Au microstructures determined by SEM, atomic force microscopy, and XRD.

  10. Study of the reactions resulting in heavy fragment formation in the collisions {sup 40}Ar + Cu, Ag and Au at 8 to 115 MeV/u; Etude des reactions avec formation d`un fragment lourd dans les collisions {sup 40}Ar + Cu, Ag et Au de 8 a 115 MeV/u

    Energy Technology Data Exchange (ETDEWEB)

    Colin, Eric Yves [Universite Claude Bernard Lyon-1, 69 - Lyon (France)

    1998-11-06

    This work concerns the study of nuclear collisions showing a heavy fragment in {sup 40}Ar + Cu, Ag and Au from 8 A MeV to 115 A MeV. The reactions are classified by centrality or collision violence via the multiplicity of charged particles detected in a 4{pi} array. For the most peripheral reactions (low multiplicities) we always find a projectile-like fragment with velocity near to that of the beam and a heavy target-like fragment with very small velocity. For the more central collisions we find the well-known incomplete fusion reactions at 17 and 27 A MeV. Above 27 A MeV two groups of very dissipative reactions are observed, both with high charged particle multiplicities. The first reaction group forms several fragments with Z {<=} 10 and average longitudinal velocity near to that of c.m. These are very rare, and are found only for the highest 1% of multiplicities. They produce a heavy fragment and a forward spray ({theta}{<=}60 angle) of particles with charge going from 1 to {approx_equal}13. The momentum carried out by the spray is randomly spread over all the particles. In spite of the increase of momentum carried by this spray with increasing beam energy, a heavy emission source is formed with 1 - 2 GeV of excitation energy. After a phase of expansion, especially signaled by Z = 1 particles, this source then evaporates many particles. Finally we observed the remaining heavy residual nucleus. (author) 117 refs., 85 figs., 12 tabs.

  11. AU-EU “Strategic Partnership”

    DEFF Research Database (Denmark)

    Rodt, Annemarie Peen; Okeke, Jide

    2013-01-01

    This article appraises strategic partnership between the African Union (AU) and European Union (EU). It examines the context and nature of AU and EU security relations and explores the conditions under which partnership has a positive impact in this regard. This includes an evaluation of converge......This article appraises strategic partnership between the African Union (AU) and European Union (EU). It examines the context and nature of AU and EU security relations and explores the conditions under which partnership has a positive impact in this regard. This includes an evaluation...... of convergence between the two organizations and its effect or lack thereof on African security. The article concludes that events leading up to and initiatives following the 2007 Joint Africa–European Union Strategy have produced a degree of AU and EU convergence, which has had limited impact on the efficacy...

  12. Structure of the thiolated Au130 cluster.

    Science.gov (United States)

    Tlahuice-Flores, Alfredo; Santiago, Ulises; Bahena, Daniel; Vinogradova, Ekaterina; Conroy, Cecil V; Ahuja, Tarushee; Bach, Stephan B H; Ponce, Arturo; Wang, Gangli; José-Yacamán, Miguel; Whetten, Robert L

    2013-10-10

    The structure of the recently discovered Au130-thiolate and -dithiolate clusters is explored in a combined experiment-theory approach. Rapid electron diffraction in scanning/transmission electron microscopy (STEM) enables atomic-resolution imaging of the gold core and the comparison with density functional theory (DFT)-optimized realistic structure models. The results are consistent with a 105-atom truncated-decahedral core protected by 25 short staple motifs, incorporating disulfide bridges linking the dithiolate ligands. The optimized structure also accounts, via time-dependent DFT (TD-DFT) simulation, for the distinctive optical absorption spectrum, and rationalizes the special stability underlying the selective formation of the Au130 cluster in high yield. The structure is distinct from, yet shares some features with, each of the known Au102 and Au144/Au146 systems.

  13. Gas-phase experiments on Au(III) photochemistry.

    Science.gov (United States)

    Marcum, Jesse C; Kaufman, Sydney H; Weber, J Mathias

    2011-04-14

    Irradiation of AuCl(4)(-) and AuCl(2)(OH)(2)(-) in the gas-phase using ultraviolet light (220-415 nm) leads to their dissociation. Observed fragment ions for AuCl(4)(-) are AuCl(3)(-) and AuCl(2)(-) and for AuCl(2)(OH)(2)(-) are AuCl(2)(-) and AuClOH(-). All fragment channels correspond to photoreduction of the gold atom to either Au(II) or Au(I) depending on the number of neutral ligands lost. Fragment branching ratios of AuCl(4)(-) are observed to be highly energy dependent and can be explained by comparison of the experimental data to calculated threshold energies obtained using density functional theory. The main observed spectral features are attributed to ligand-to-metal charge transfer transitions. These results are discussed in the context of the molecular-level mechanisms of Au(III) photochemistry.

  14. Magnetic depth profiling of Fe/Au multilayer using neutron ...

    Indian Academy of Sciences (India)

    Au multilayer sample for characterizing the layer structure and magnetic moment density profile. Fe/Au multilayer shows strong spin-dependent scattering at interfaces, making it a prospective GMR material. Fe/Au multilayer with bilayer ...

  15. Influence of Bottom Quark Jet Quenching on Single ElectronTomography of Au+Au

    Energy Technology Data Exchange (ETDEWEB)

    Djordjevic, Magdalena; Gyulassy, Miklos; Vogt, Ramona; Wicks, Simon

    2005-07-12

    High transverse momentum single (non-photonic) electrons are shown to be sensitive to the stopping power of both bottom, b, and charm, c, quarks in AA collisions. We apply the DGLV theory of radiative energy loss to predict c and b quark jet quenching and compare the FONLL and PYTHIA heavy flavor fragmentation and decay schemes. We show that single electrons in the p{sub T} = 5-10 GeV range are dominated by the decay of b quarks rather than the more strongly quenched c quarks in Au+Au collisions at {radical}s = 200 AGeV. The smaller b quark energy loss, even for extreme opacities with gluon rapidity densities up to 3500, is predicted to limit the nuclear modification factor, R{sub AA}, of single electrons to the range R{sub AA} {approx} 0.5-0.6, in contrast to previous predictions of R{sub AA} {le} 0.2-0.3 based on taking only c quark jet fragmentation into account.

  16. Première mesure de l'asymétrie azimutale de la production du $J/\\psi$ vers l'avant dans les collisions Au+Au à 200 GeV par paire de nucléons avec l'expérience PHENIX

    CERN Document Server

    Silvestre Tello, Catherine; Pereira da Costa, Hugo

    2008-01-01

    One of hight energy experiment main goal is the study of nuclear matter under extreme conditions. Ultra- relativistic Au+Au collisions at 200 GeV per binary nucleon-nucleon collision could generate high enough temperature and energy density to form a new state of matter, the quark gluon plasma (QGP), where quarks and gluons would be free from strong interactions. The J/ψ is a heavy particle made of charm quarks (c ̄). The study of its production has been suggested c a QGP probe. J/ψ suppression was initially expected if a QGP was formed because of screening between charm quarks within a dense colored medium. Lots of J/ψ measurements have been made at SPS (CERN) and RHIC (BNL). They have allowed to point out this suppression but also showed the presence of additional mechanisms, which lead to a more difficult interpretation of the results. The PHENIX experiment is the only one of RHIC experiments to be able to measure the J/ψ at positive √ rapidity via its disintegration into two muons. In 2007, RHIC co...

  17. Au dissolution during the anodic response of short-chain alkylthiols with polycrystalline Au electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Scott R. [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada); Guerra, Eduard [School of Engineering, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada); Siemann, Stefan [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada); Shepherd, Jeffrey L., E-mail: jshepherd@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

    2011-10-01

    Highlights: > 3-Mercaptopropionic acid (MPA) or meso-2,3-dimercaptosuccinic acid (DMSA) mediated Au corrosion in aqueous electrolytes at anodic potentials. > Au is roughened and passivated by an insoluble Au-MPA product. > Au is leached into the aqueous electrolyte as a soluble Au-DMSA species ({approx}60 ppb, 12 h). - Abstract: The electrochemical characteristics of polycrystalline Au in LiClO{sub 4} electrolyte solutions containing 3-mercaptopropionic acid (MPA) or meso-2,3-dimercaptosuccinic acid (DMSA) were studied with linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) over a wide range of positive potentials vs. Ag/AgCl. The EIS data exhibited linear capacitive behaviour at 0.0 V with either MPA or DMSA added directly to the electrolyte suggesting the formation of an adsorbed layer of the alkylthiol on the electrode surface. Above this potential, a single well-defined impedance loop appeared for electrolyte solutions containing DMSA or MPA, an observation indicative of a charge transfer reaction that could be related to several processes including oxidative desorption, oxidation of the alkylthiol, or Au oxidation/dissolution. To test for Au dissolution, the electrode was held at 0.8 V vs. Ag/AgCl for 12 h in electrolytes containing MPA or DMSA followed by surface analysis with Atomic Force Microscopy and solution analysis with Atomic Absorption Spectroscopy. When the electrolyte contained MPA, the extended potential holding procedure resulted in significant roughening of the electrode with no detectable quantities of Au in the electrolyte. X-ray photoelectron spectroscopy (XPS) analysis of the Au surface revealed an additional species in the Au 4f{sub 7/2} spectrum indicating the presence of an insoluble electrochemically generated Au(I)-MPA species. When the electrolyte contained DMSA, the Au electrode appeared smoother, 56.6 {+-} 9.6 ppb of Au was detected in the electrolyte and the XPS analysis displayed a single species in the

  18. Au/Au@polythiophene core/shell nanospheres for heterogeneous catalysis of nitroarenes.

    Science.gov (United States)

    Shin, Hye-Seon; Huh, Seong

    2012-11-01

    Monodisperse Au/Au@polythiophene core/shell nanospheres were facilely prepared through the reduction of gold precursor, AuCl₄⁻, by 2-thiopheneacetonitrile in an aqueous solution. Concomitantly, 2-thiopheneacetonitrile polymerized during this redox process. As a result, Au nanoparticle was encapsulated by conductive polymer shell to afford novel core/shell nanospheres. Interestingly, the shell was composed of very tiny Au nanoparticles surrounded with thiophene polymers. Thus, the new material is best described as Au/Au@polythiophene core/shell nanospheres. FT-IR spectroscopy revealed that the Au nanoparticles were coordinated by the C≡N groups of the polythiophene shell. Some of the C≡N groups were partially hydrolyzed into COOH groups during the redox process because of the acidic reaction condition. The shell was conductive based on the typical ohmic behavior found in electrical measurement. The Au/Au@polythiophene core/shell nanospheres were found to be very active catalysts for the hydrogenation of various nitroarene compounds into corresponding aminoarene compounds in the presence of NaBH₄. Both hydrophilic and hydrophobic nitroarenes were efficiently hydrogenated under mild conditions.

  19. Filipino au pairs on the move

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2016-01-01

    interdependence, whilst they continuously form their trajectories in relation to opportunities and restraints posed along the way by their local and transnational social relations. The article argues that examinations of migration trajectories benefit from broadening the research out in both time and space......Most Filipina au pairs in Denmark send remittances back home, and for many, au pairing forms part of longer-term migration trajectories. This article explores how Filipina au pairs try to carve out a future for themselves abroad. It shows that they navigate within tight webs of financial...

  20. Becoming independent through au pair migration

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    . This article argues that, despite this critique, au pairing does play an important formative role for young Filipinas because it opens up for experiences abroad that enable them to be recognised as independent adults in Philippine society. Rather than autonomy, however, au pairs define their independence...... in terms of their capacity to assume responsibility for others, thereby achieving a position of social respect. Based on ethnographic fieldwork in Denmark and the Philippines, this article explores how young Filipinas use the social, economic, and cultural resources they gain from their au pair stay abroad...

  1. Synthesis of ultrathin face-centered-cubic Au@Pt and Au@Pd core-shell nanoplates from hexagonal-close-packed Au square sheets

    KAUST Repository

    Fan, Zhanxi

    2015-03-17

    The synthesis of ultrathin face-centered-cubic (fcc) Au@Pt rhombic nanoplates is reported through the epitaxial growth of Pt on hexagonal-close-packed (hcp) Au square sheets (AuSSs). The Pt-layer growth results in a hcp-to-fcc phase transformation of the AuSSs under ambient conditions. Interestingly, the obtained fcc Au@Pt rhombic nanoplates demonstrate a unique (101)f orientation with the same atomic arrangement extending from the Au core to the Pt shell. Importantly, this method can be extended to the epitaxial growth of Pd on hcp AuSSs, resulting in the unprecedented formation of fcc Au@Pd rhombic nanoplates with (101)f orientation. Additionally, a small amount of fcc (100)f-oriented Au@Pt and Au@Pd square nanoplates are obtained with the Au@Pt and Au@Pd rhombic nanoplates, respectively. We believe that these findings will shed new light on the synthesis of novel noble bimetallic nanostructures. Phase change: Ultrathin Au@Pt and Au@Pd core-shell nanoplates were prepared from Au square sheets. A phase transformation from hexagonal close-packed (hcp) to face-centered cubic (fcc) is observed upon coating the hcp Au square sheets with Pt or Pd under ambient conditions. The prepared fcc Au@Pt and Au@Pd rhombic nanoplates demonstrate unique (101)f orientation (picture shows a typical fcc Au@Pt rhombic nanoplate). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Et pourquoi pas au CERN ?

    CERN Multimedia

    Staff Association

    2015-01-01

    Télétravail ou travail à distance, aménagement des horaires de travail et autres évolutions favorables à un meilleur équilibre vie privée et vie professionnelle sont adoptés par nombre d’entreprises et d’organisations !   Rendu possible grâce au développement de nouvelles technologies dont Internet, le travail à distance séduit de plus en plus de personnels, ainsi que de plus en plus de sociétés qui y trouvent des avantages en matière de gestion de l’espace, de sécurité (moins de trajets domicile-entreprise), de développement durable (moins de pollution), de motivation et de bien-être de leurs personnels. Les horaires aménagés, voire les « core-hours1 », sont également des pratiques de plus e...

  3. Comparative efficiencies of photothermal destruction of malignant cells using antibody-coated silica-Au nanoshells, hollow Au/Ag nanospheres and Au nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Fong-Yu; Chen, Chen-Tai; Yeh, Chen-Sheng, E-mail: csyeh@mail.ncku.edu.t [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China)

    2009-10-21

    Three Au-based nanomaterials (silica-Au nanoshells, hollow Au/Ag nanospheres and Au nanorods) were evaluated for their comparative photothermal efficiencies at killing three types of malignant cells (A549 lung cancer cells, HeLa cervix cancer cells and TCC bladder cancer cells) using a CW NIR laser. Photodestructive efficiency was evaluated as a function of the number of nanoparticles required to destroy the cancer cells under 808 nm laser wavelength at fixed laser power. Of the three nanomaterials, silica/Au nanoshells needed the minimum number of particles to produce effective photodestruction, whereas Au nanorods needed the largest number of particles. Together with the calculated photothermal conversion efficiency, the photothermal efficiency rankings are silica-Au nanoshells > hollow Au/Ag nanospheres > Au nanorods. Additionally, we found that HeLa cells seem to present better heat tolerance than the other two cancer cell lines.

  4. Photovoltage responses of graphene-Au heterojunctions

    Science.gov (United States)

    Li, Kai; Ying, Xiangxiao; Wang, Juan; Wang, Jun; Jiang, Yadong; Liu, Zhijun

    2017-10-01

    As an emerging 2D material, graphene's several unique properties, such as high electron mobility, zero-bandgap and low density of states, present new opportunities for light detections. Here, we report on photovoltage responses of graphene-Au heterojunctions, which are made of monolayer graphene sheets atop Au electrodes designed as finger-shape and rectangle-shape, respectively. Besides confirming the critical role of space charge regions located at the graphene-Au boundary, photovoltage responses are measured in the visible to infrared spectral region with a cut-off wavelength at about 980 nm, which is likely imposed by the Pauli blocking of interband transition in the contact-doped graphene. The photoresponsivity is shown to decrease with increasing wavelength. A band diagram of the graphene-Au heterojunction is proposed to understand the photoresponse mechanism.

  5. Intense fluorescence of Au 20

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chongqi; Harbich, Wolfgang; Sementa, Luca; Ghiringhelli, Luca; Apra, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Brune, Harald

    2017-08-21

    Ligand-protected Au clusters are non-bleaching fluorescence markers in bio- and medical applications. We show that their fluorescence is an intrinsic property of the Au cluster itself. We find a very intense and sharp fluorescence peak located at λ =739.2 nm (1.68 eV) for Au20 clusters in a Ne matrix held at 6 K. The fluorescence reflects the HOMO-LUMO diabatic bandgap of the cluster. The cluster shows a very rich absorption fine structure reminiscent of well defined molecule-like quantum levels. These levels are resolved since Au20 has only one stable isomer (tetrahedral), therefore our sample is mono-disperse in cluster size and conformation. Density-functional theory (DFT) and time-dependent DFT calculations clarify the nature of optical absorptionand predict both main absorption peaks and intrinsic fluorescence in good agreement with experiment.

  6. 22 CFR 62.31 - Au pairs.

    Science.gov (United States)

    2010-04-01

    ....31 Au pairs. (a) Introduction. This section governs Department of State-designated exchange visitor... requirements set forth at § 62.10 sponsors shall: (1) Inform all host families of the philosophy, rules, and...

  7. Unravelling Thiol’s Role in Directing Asymmetric Growth of Au Nanorod–Au Nanoparticle Dimers

    KAUST Repository

    Huang, Jianfeng

    2015-12-15

    Asymmetric nanocrystals have practical significance in nanotechnologies but present fundamental synthetic challenges. Thiol ligands have proven effective in breaking the symmetric growth of metallic nanocrystals but their exact roles in the synthesis remain elusive. Here, we synthesized an unprecedented Au nanorod-Au nanoparticle (AuNR-AuNP) dimer structure with the assistance of a thiol ligand. On the basis of our experimental observations, we unraveled for the first time that the thiol could cause an inhomogeneous distribution of surface strains on the seed crystals as well as a modulated reduction rate of metal precursors, which jointly induced the asymmetric growth of monometallic dimers. © 2015 American Chemical Society.

  8. "Dealloying" Phase Separation during Growth of Au on Ni(110)

    DEFF Research Database (Denmark)

    Nielsen, L. Pleth; Besenbacher, Flemming; Stensgaard, I.

    1995-01-01

    Combined scanning tunneling microscopy and ion-scattering studies have revealed a new "dealloying" phase transition during the growth of Au on Ni(110). The Au atoms, which initially alloy into the Ni(110) surface, phase separate into a vacancy-stabilized Au dimer-trimer chain structure at Au...

  9. Enantioselective separation on chiral Au nanoparticles.

    Science.gov (United States)

    Shukla, Nisha; Bartel, Melissa A; Gellman, Andrew J

    2010-06-30

    The surfaces of chemically synthesized Au nanoparticles have been modified with d- or l-cysteine to render them chiral and enantioselective for adsorption of chiral molecules. Their enantioselective interaction with chiral compounds has been probed by optical rotation measurements during exposure to enantiomerically pure and racemic propylene oxide. The ability of optical rotation to detect enantiospecific adsorption arises from the fact that the specific rotation of polarized light by (R)- and (S)-propylene oxide is enhanced by interaction with Au nanoparticles. This effect is related to previous observations of enhanced circular dichroism by Au nanoparticles modified by chiral adsorbates. More importantly, chiral Au nanoparticles modified with either d- or l-cysteine selectively adsorb one enantiomer of propylene oxide from a solution of racemic propylene oxide, thus leaving an enantiomeric excess in the solution phase. Au nanoparticles modified with l-cysteine (d-cysteine) selectively adsorb the (R)-propylene oxide ((S)-propylene oxide). A simple model has been developed that allows extraction of the enantiospecific equilibrium constants for (R)- and (S)-propylene oxide adsorption on the chiral Au nanoparticles.

  10. Apprentissages techniques : L'apprentissage au CERN

    CERN Document Server

    2004-01-01

    APPRENTISSAGES TECHNIQUES GESTION ET DEVELOPPEMENT DU PERSONNEL HR/PMD L'APPRENTISSAGE AU CERN pour les professions d'électronicien(ne) et de laborantin(e) en physique L'apprentissage au CERN est régi par les lois, règlements et contrats en vigueur dans le Canton de Genève. En cas de réussite à l'examen de fin d'apprentissage, les apprentis obtiennent le Certificat Fédéral de Capacité Suisse (CFC). 7 places au total sont ouvertes au recrutement pour les deux professions. L'apprentissage dure 4 ans. Minima requis pour faire acte de candidature : • avoir au moins 15 ans et moins de 21 ans à la date de début de l'apprentissage • avoir terminé la scolarité obligatoire, au minimum 9ème du Cycle d'orientation genevois (3ème en France) • être ressortissant d'un pays membre du CERN (Allemagne, Autriche, Belgiqu...

  11. Extraction of the high transverse momentum photons in proton + proton collisions at 200 GeV in the PHENIX experiment at RHIC; Isolation des photons de grande impulsion transverse dans les collisions proton+proton a 200 GeV dans l'experience PHENIX au RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Hadl Henni, Ahmed [Ecole doctorale STIM, Sciences et Technologies de l' Information et des Materiaux, Ecole Centrale de Nantes, Universite de Nantes, Ecole des Mines de Nantes, 1 rue de la Noe, BP 92101, 44321 Nantes Cedex 3 (France)

    2007-02-15

    Ultra-relativistic heavy ions collisions allow to reach a hot and dense matter. This new state, called Quarks and Gluons Plasma (QGP), would exist at the first moment of our universe according to the Big Bang theory. The PHENIX experiment, one of the interaction point of the RHIC collider at Brookhaven National Laboratory (USA), aims to study the QGP's signatures. Photons don't interact strongly with the matter and so are an accurate tool to explore the phase of QGP. Moreover photons are emitted during all the phases of the nuclear collision: from the initial state to the final hadronization. We will present a direct photon, produced by hard scattering process in the beginning of the collision, identification method (SICA, Spectroscopic Isolation Cut Analysis) applied on p + p collisions at 200 GeV. This method allows for a better discrimination between direct photons and the other contribution (mainly the electromagnetic decay of the neutral pion). One could find in this thesis the direct photon rate production obtained by SICA and compared to other analysis. With the p + p collisions we have an important reference for the more heavier collisions (Au + Au) where we assume the QGP formation. (author)

  12. Study of in-medium effects with the Au + Au FOPI data at 400 A.MeV

    Energy Technology Data Exchange (ETDEWEB)

    Rammillien, V.; Dupieux, P.; Alard, J.P.; Amouroux, V.; Bastid, N.; Berger, L.; Boussange, S.; Fraysse, L.; Ibnouzahir, M.; Montarou, G.; FOPI Collaboration

    1994-12-31

    New experimental data obtained with the FOPI detector at SIS for the Au + Au heavy ion collisions at 400 A.MeV incident energy are presented. Sideward flow and nuclear stopping are studied as a function of the centrality of the collisions. In order to study the nuclear in-medium effects, these results are compared with the predictions of two different QMD versions. The first one offers a fully microscopic calculation of the cross-sections and potential in the G-matrix formalism and naturally includes the in-medium effects. The second one uses a standard Skyrme potential plus a momentum dependent term in order to mimic the in-medium effects. (author). 15 refs.

  13. Fully Cationized Gold Clusters: Synthesis of Au25(SR+)18.

    Science.gov (United States)

    Ishida, Yohei; Narita, Kunihiro; Yonezawa, Tetsu; Whetten, Robert L

    2016-10-06

    Although many thiolate-protected Au clusters with different numbers of Au atoms and a variety of thiolate ligands have been synthesized, to date there has been no report of a fully cationized Au cluster protected with cationic thiolates. Herein, we report the synthesis of the first member of a new series of thiolate-protected Au cluster molecules: a fully cationized Au 25 (SR + ) 18 cluster.

  14. 100-MeV proton beam intensity measurement by Au activation analysis using {sup 197}Au(p, pn){sup 196}Au and {sup 197}Au(p, p3n){sup 194}Au reactions

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari Oranj, Leila [Division of Advanced Nuclear Engineering, POSTECH, Pohang 37673 (Korea, Republic of); Jung, Nam-Suk; Oh, Joo-Hee [Pohang Accelerator Laboratory, POSTECH, Pohang 37673 (Korea, Republic of); Lee, Hee-Seock, E-mail: lee@postech.ac.kr [Pohang Accelerator Laboratory, POSTECH, Pohang 37673 (Korea, Republic of)

    2016-05-15

    The proton beam intensity of a 100-MeV proton linac at the Korea Multi-purpose Accelerator Complex (KOMAC) was measured by an Au activation analysis using {sup 197}Au(p, pn){sup 196}Au and {sup 197}Au(p, p3n){sup 194}Au reactions to determine the accuracy and precision of beam intensity measurement using Gafchromic film dosimetry method. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of Au, Al foils and Pb plates. The yields of produced radio-nuclei in Au foils were obtained by gamma-ray spectroscopy. The FLUKA code was employed to calculate the energy spectrum of protons onto the front surface of Au foils located at three different depth points of the target and also to investigate the condition of incident beam on the target. A good agreement was found between the beam intensity measurements using the activation analysis method at three different depth points of the target. An excellent agreement was also observed between the beam intensity measurements using the Au activation analysis method and the dosimetry method using Gafchromic film.

  15. Charged-to-neutral correlation at forward rapidity in Au + Au collisions at sNN=200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2015-03-01

    Event-by-event fluctuations of the multiplicities of inclusive charged particles and photons at forward rapidity in Au + Au collisions at root s(NN) = 200 GeV have been studied. The dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidence of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as base lines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A nonzero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation owing to particle decay. Results are compared to the expectations based on the generic production mechanism of pions owing to isospin symmetry, for which no significant (<1%) deviation is observed.

  16. Toward hybrid Au nanorods @ M (Au, Ag, Pd and Pt) core-shell heterostructures for ultrasensitive SERS probes

    Science.gov (United States)

    Xie, Xiaobin; Gao, Guanhui; Kang, Shendong; Lei, Yanhua; Pan, Zhengyin; Shibayama, Tamaki; Cai, Lintao

    2017-06-01

    Being able to precisely control the morphologies of noble metallic nanostructures is of essential significance for promoting the surface-enhanced Raman scattering (SERS) effect. Herein, we demonstrate an overgrowth strategy for synthesizing Au @ M (M = Au, Ag, Pd, Pt) core-shell heterogeneous nanocrystals with an orientated structural evolution and highly improved properties by using Au nanorods as seeds. With the same reaction condition system applied, we obtain four well-designed heterostructures with diverse shapes, including Au concave nanocuboids (Au CNs), Au @ Ag crystalizing face central cube nanopeanuts, Au @ Pd porous nanocuboids and Au @ Pt nanotrepangs. Subsequently, the exact overgrowth mechanism of the above heterostructural building blocks is further analysed via the systematic optimiziation of a series of fabrications. Remarkably, the well-defined Au CNs and Au @ Ag nanopeanuts both exhibit highly promoted SERS activity. We expect to be able to supply a facile strategy for the fabrication of multimetallic heterogeneous nanostructures, exploring the high SERS effect and catalytic activities.

  17. INDRA at GSI; INDRA au GSI

    Energy Technology Data Exchange (ETDEWEB)

    Bougault, R.; Bocage, F.; Durand, D.; Lopez, O.; Steckmeyer, J.C.; Tamain, B.; Vient, E. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France); Collaboration INDRA: IPN-Orsay, DAPNIA-Saclay, SUBATECH-Nantes, IPN- Lyon, GANIL-Caen

    1997-12-31

    In connection to the decision of installing the INDRA detector by the SIS synchrocyclotron at GSI (Darmstadt, Germany) the report presents the tasks taken into account by the LPC-Caen. These refer to the detector displacement and (mechanical) installation at GSI, the tests before beam (i.e. electronics acquisition software, detectors, etc.) as well as the data acquisition and processing. The physical pro-arguments mention the possibility of disposing of heavy ion beams in a range from 50 MeV to several GeV/nucleon so extending the study of multifragmentation done at GANIL between 30 and 90 MeV/nucleon. More specific, the scientific program of INDRA at GSI inserts studies between those done at around Fermi energy, were the reaction mechanisms are of type of deep inelastic scattering/incomplete fusion, and the studies in the relativistic energy domain where the individual properties of nucleons and transparency of nuclear matter implies mechanisms of the participant-spectator type (fire-ball creation). Also mentioned as fields of extensive studies are: the multifragmentation and its fundamental relation with the nuclear matter equation of state, the role of reaction dynamics in the appearance of collective effects of the radial flow type and its relations with the nuclear compressibility and phase transitions and the thermodynamics of nuclear matter. It appeared that the heavy systems Xe + Sn and Au + Au are the best compromise for the different topics to be approached. The bombarding energies extend from 50 to 150 MeV/nucleon. The report ends with the table giving for six heavy systems (Xe + Sn, Au + Au, C + Au, Ar + Au and P + Au) the required bombarding energies 15 refs.

  18. The extraction characteristic of Au-Ag from Au concentrate by thiourea solution

    Science.gov (United States)

    Kim, Bongju; Cho, Kanghee; On, Hyunsung; Choi, Nagchoul; Park, Cheonyoung

    2013-04-01

    The cyanidation process has been used commercially for the past 100 years, there are ores that are not amenable to treatment by cyanide. Interest in alternative lixiviants, such as thiourea, halogens, thiosulfate and malononitrile, has been revived as a result of a major increase in gold price, which has stimulated new developments in extraction technology, combined with environmental concern. The Au extraction process using the thiourea solvent has many advantages over the cyanidation process, including higher leaching rates, faster extraction time and less than toxicity. The purpose of this study was investigated to the extraction characteristic of Au-Ag from two different Au concentrate (sulfuric acid washing and roasting) under various experiment conditions (thiourea concentration, pH of solvent, temperature) by thiourea solvent. The result of extraction experiment showed that the Au-Ag extraction was a fast extraction process, reaching equilibrium (maximum extraction rate) within 30 min. The Au-Ag extraction rate was higher in the roasted concentrate than in the sulfuric acid washing. The higher the Au-Ag extraction rate (Au - 70.87%, Ag - 98.12%) from roasted concentrate was found when the more concentration of thiourea increased, pH decreased and extraction temperature increased. This study informs extraction method basic knowledge when thiourea was a possibility to eco-/economic resources of Au-Ag utilization studies including the hydrometallurgy.

  19. Au/ZnO nanoarchitectures with Au as both supporter and antenna of visible-light

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tianyu; Chen, Wei; Hua, Yuxiang; Liu, Xiaoheng, E-mail: xhliu@mail.njust.edu.cn

    2017-01-15

    Highlights: • An inversed Au/ZnO nanostructure was fabricated with ZnO loaded onto Au. • The Au/ZnO nanocomposites showed enhanced properties in visible-light photocatalysis. • The SPR effect of Au was considered important for visible-light photocatalysis. - Abstract: In this paper, we fabricate Au/ZnO nanostructure with smaller ZnO nanoparticles loaded onto bigger gold nanoparticles via combining seed-mediated method and sol-gel method. The obtained Au/ZnO nanocomposites exhibit excellent properties in photocatalysis process like methyl orange (MO) degradation and oxidative conversion of methanol into formaldehyde under visible light irradiation. The enhanced properties were ascribed to the surface plasmon resonance (SPR) effect of Au nanoparticles, which could contribute to the separation of photo-excited electrons and holes and facilitate the process of absorbing visible light. This paper contributes to the emergence of multi-functional nanocomposites with possible applications in visible-light driven photocatalysts and makes the Au/ZnO photocatalyst an exceptional choice for practical applications such as environmental purification of organic pollutants in aqueous solution and the synthesis of fine chemicals and intermediates.

  20. Using supported Au nanoparticles as starting material for preparing uniform Au/Pd bimetallic catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Villa, Alberto [Universita di Milano, Italy; Prati, Laura [Universita di Milano, Italy; Su, Dangshen [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Wang, Di [Fritz Haber Institute of the Max Planck Society, Berlin, Germany; Veith, Gabriel M [ORNL

    2010-01-01

    One of the best methods for producing bulk homogeneous (composition) supported bimetallic AuPd clusters involves the immobilization of a protected Au seed followed by the addition of Pd. This paper investigates the importance of this gold seed in controlling the resulting bimetallic AuPd clusters structures, sizes and catalytic activities by investigating three different gold seeds. Uniform Au-Pd alloy were obtained when a steric/electrostatic protecting group, poly(vinyl alcohol) (PVA), was used to form the gold clusters on activated carbon (AC). In contrast Au/AC precursors prepared using Au nanoparticles with only electrostatic stabilization (tetrakis(hydroxypropyl)phosphonium chloride (THPC)), or no stabilization (magnetron sputtering) produced inhomogeneous alloys and segregation of the gold and palladium. The uniform alloyed catalyst (Pd{at}Au{sub PVA}/AC) is the most active and selective catalyst, while the inhomogenous catalysts are less active and selective. Further study of the PVA protected Au clusters revealed that the amount of PVA used is also critical for the preparation of uniform alloyed catalyst, their stability, and their catalytic activity.

  1. Stability of gold cages (Au16 and Au17) at finite temperature

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... We have employed ab initio molecular dynamics to investigate the stability of the smallest gold cages, namely Au16 and Au17, at finite temperatures. First, we obtain the ground state structure along with at least 50 distinct isomers for both the clusters. This is followed by the finite temperature simulations of ...

  2. Low-temperature solution synthesis of the non-equilibrium ordered intermetallic compounds Au3Fe, Au3Co, and Au3Ni as nanocrystals.

    Science.gov (United States)

    Vasquez, Yolanda; Luo, Zhiping; Schaak, Raymond E

    2008-09-10

    Alloys and intermetallic compounds of Au with the 3d transition metals Fe, Co, and Ni are nonequilibrium phases that have many useful potential applications as catalytic, magnetic, optic, and multifunctional magneto-optic materials. However, the atomically ordered Au-M (M = Fe, Co, Ni) intermetallics are particularly elusive from a synthetic standpoint. Here we report the low-temperature solution synthesis of the L12 (Cu3Au-type) intermetallic compounds Au3Fe, Au3Co, and Au3Ni using n-butyllithium as a reducing agent. Reaction pathway studies for the Au3Co system indicate that Au nucleates first, followed by Co incorporation to form the intermetallic. The nonequilibrium intermetallic nanocrystals have been characterized by powder XRD, TEM, EDS, selected area electron diffraction, and nanobeam electron diffraction, which collectively confirm the compositions and superlattice structures.

  3. Synthesis and characterization in AuCu–Si nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Novelo, T.E., E-mail: tenovelo@hotmail.com [Centro de Investigación en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnología, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109 Chihuahua, Chihuahua Mexico (Mexico); Amézaga-Madrid, P. [Centro de Investigación en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnología, Av. Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109 Chihuahua, Chihuahua Mexico (Mexico); Maldonado, R.D. [Universidad Anáhuac-Mayab, Carretera Mérida-Progreso Km. 15.5 A.P. 96-Cordemex, CP. 97310 Mérida, Yucatán Mexico (Mexico); Oliva, A.I. [Centro de Investigación y de Estudios Avanzados el IPN Unidad Mérida, Departamento de Física Aplicada, Km 6 Antigua Carretera a Progreso, A.P. 73-Cordemex, 97310 Mérida, Yucatán Mexico (Mexico); Alonzo-Medina, G.M. [Universidad Anáhuac-Mayab, Carretera Mérida-Progreso Km. 15.5 A.P. 96-Cordemex, CP. 97310 Mérida, Yucatán Mexico (Mexico)

    2015-03-15

    Au/Cu bilayers with different Au:Cu concentrations (25:75, 50:50 and 75:25 at.%) were deposited on Si(100) substrates by thermal evaporation. The thicknesses of all Au/Cu bilayers were 150 nm. The alloys were prepared by thermal diffusion into a vacuum oven with argon atmosphere at 690 K during 1 h. X-ray diffraction analysis revealed different phases of AuCu and CuSi alloys in the samples after annealing process. CuSi alloys were mainly obtained for 25:75 at.% samples, meanwhile the AuCuII phase dominates for samples prepared with 50:50 at.%. Additionally, the Au:Cu alloys with 75:25 at.%, produce Au{sub 2}Cu{sub 3} and Au{sub 3}Cu phases. The formed alloys were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) to study the morphology and the elemental concentration of the formed alloys. - Highlights: • AuCu/Si alloy thin films were prepared by thermal diffusion. • Alloys prepared with 50 at.% of Au produce the AuCuII phase. • Alloys prepared with 75 at.% of Au produce Au{sub 3}Cu and Au{sub 2}Cu{sub 3} phases. • All alloys present diffusion of Si and Cu through the CuSi alloy formation.

  4. Au nanoparticles films used in biological sensing

    Energy Technology Data Exchange (ETDEWEB)

    Rosales Perez, M; Delgado Macuil, R; Rojas Lopez, M; Gayou, V L [Centro de Investigacion en BiotecnologIa Aplicada del IPN, Tepetitla Tlaxcala Mexico C.P. 90700 (Mexico); Sanchez Ramirez, J F, E-mail: mrosalespe@ipn.m [CICATA Legaria Instituto Politecnico Nacional, Mexico Distrito Federal (Mexico)

    2009-05-01

    Lactobacillus para paracasei are used commonly as functional food and probiotic substances. In this work Au nanoparticles self-assembled films were used for Lactobacillus para paracasei determination at five different concentrations. Functionalized substrates were immersed in a colloidal solution for one and a half hour at room temperature and dried at room temperature during four hours. After that, drops of Lactobacillus para paracasei in aqueous solution were put into the Au nanoparticles film and let dry at room temperature for another two hours. Infrared spectroscopy in attenuated total reflectance sampling mode was used to observe generation peaks due to substrate silanization, enhancement of Si-O band intensity due to the Au colloids added to silanized substrate and also to observe the enhancement of Lactobacillus para paracasei infrared intensity of the characteristic frequencies at 1650, 1534 and 1450 cm{sup -1} due to surface enhancement infrared absorption.

  5. Total structure determination of thiolate-protected Au38 nanoparticles.

    Science.gov (United States)

    Qian, Huifeng; Eckenhoff, William T; Zhu, Yan; Pintauer, Tomislav; Jin, Rongchao

    2010-06-23

    We report the total structure of Au(38)(SC(2)H(4)Ph)(24) nanoparticles determined by single crystal X-ray crystallography. This nanoparticle is based upon a face-fused Au(23) biicosahedral core, which is further capped by three monomeric Au(SR)(2) staples at the waist of the Au(23) rod and six dimeric staples with three on the top icosahedron and other three on the bottom icosahedron. The six Au(2)(SR)(3) staples are arranged in a staggered configuration, and the Au(38)S(24) framework has a C(3) rotation axis.

  6. Au nanorice assemble electrolytically into mesostars.

    Science.gov (United States)

    Bardhan, Rizia; Neumann, Oara; Mirin, Nikolay; Wang, Hui; Halas, Naomi J

    2009-02-24

    Star-shaped mesotructures are formed when an aqueous suspension of Au nanorice particles, which consist of prolate hematite cores and a thin Au shell, is subjected to an electric current. The nanorice particles assemble to form hyperbranched micrometer-scale mesostars. To our knowledge, this is the first reported observation of nanoparticle assembly into larger ordered structures under the influence of an electrochemical process (H(2)O electrolysis). The assembly is accompanied by significant modifications in the morphology, dimensions, chemical composition, crystallographic structure, and optical properties of the constituent nanoparticles.

  7. On the Stark broadening in the Au I and Au II spectra from a helium plasma

    Science.gov (United States)

    Djeniže, S.

    2009-03-01

    The Stark FWHM (Full-Width at Half of the Maximal line intensity, W) of 5 neutral and 26 singly ionized gold (Au I and Au II, respectively) spectral lines have been measured in laboratory helium plasma at approximately 16,600 K electron temperature and 7.4 × 10 22 m - 3 electron density. Five Au I and ten Au II W values are reported for the first time. The Au II W values are compared with recent theoretical data, calculated based on a modified semi-empirical approach, and also with existing experimental W values. Our normalized Stark widths are six times higher than those measured in a laser-produced plasma. Possible explanation of this is recommended here. An agreement (within the accuracy of the experiment and uncertainties of the theoretical approach used) with the recently calculated W data was found in the 6p-7s Au II transition. The calculated hyperfine splitting for the five Au II lines in the 6s-6p transition is also presented. At the stated helium plasma conditions, Stark broadening has been found to be the dominant mechanism in the Au I and Au II line shape formation. A modified version of the linear low-pressure pulsed arc was used as a plasma source operated in helium, with gold atoms as impurities evaporated from the thin gold cylindrical plates located in the homogeneous part of the discharge, providing conditions free of self-absorption. This plasma source ensures good conditions for generation of excited gold ions due to Penning and charge exchange effects.

  8. A novel Au SINE sequence found in a gymnosperm.

    Science.gov (United States)

    Yagi, Eiki; Akita, Toru; Kawahara, Taihachi

    2011-01-01

    Although many SINE families have been identified in the animal kingdom, only a few SINE families have been identified in plants, and their distribution is somewhat limited. The Au SINE (Au) has been found discontinuously in basal angiosperms, monocots, and eudicots. In this study, we examined the presence of the Au in gymnosperms and ferns by PCR using internal primers for Au. As a result, we found Au in a gymnosperm species, Ephedra ciliata. Therefore, Au was supposed to be present in the common ancestor of angiosperms and gymnosperms. The Au in E. ciliate was 15 bp shorter than the consensus sequence, which is similar to the Au SINE found in Glycine. However, the 3'end of the Au found in E. ciliate was more similar to the 3'end of the Medicago-type Au than that of the Glycine-type Au. A phylogenetic tree indicated that the Au sequence from E. ciliate is more closely related to the sequence found in Glycine than that found in Medicago/Lotus. These results indicated that Au were present in both angiosperms and gymnosperms.

  9. Inclusive pi^0, eta, and direct photon production at high transverse momentum in p+p and d+Au collisions at sqrt(s_NN) = 200 GeV

    Energy Technology Data Exchange (ETDEWEB)

    STAR Collaboration; Abelev, Betty

    2010-07-07

    We report a measurement of high-p{sub T} inclusive {pi}{sup 0}, {eta}, and direct photon production in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV at midrapidity (0 < {eta} < 1). Photons from the decay {pi}{sup 0} {yields} {gamma}{gamma} were detected in the Barrel Electromagnetic Calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The {eta} {yields} {gamma}{gamma} decay was also observed and constituted the first {eta} measurement by STAR. The first direct photon cross section measurement by STAR is also presented, the signal was extracted statistically by subtracting the {pi}{sup 0}, {eta}, and {omega}(782) decay background from the inclusive photon distribution observed in the calorimeter. The analysis is described in detail, and the results are found to be in good agreement with earlier measurements and with next-to-leading order perturbative QCD calculations.

  10. La cardiomyopathie dilatee au centre hospitalier Universitaire ...

    African Journals Online (AJOL)

    La cardiomyopathie dilatee au centre hospitalier Universitaire Tokoin de Lome : A propos de 74 cas hospitalises. ... Le traitement médical a fait appel aux diurétiques (85,1%), aux inhibiteurs de l'enzyme de conversion de l'angiotensine (83,8%) et aux digitaliques (55,4%). Des antiarythmiques, des antiaggrégants ...

  11. Nanoporous Au: an unsupported pure gold catalyst?

    Energy Technology Data Exchange (ETDEWEB)

    Wittstock, A; Neumann, B; Schaefer, A; Dumbuya, K; Kuebel, C; Biener, M; Zielasek, V; Steinrueck, H; Gottfried, M; Biener, J; Hamza, A; B?umer, M

    2008-09-04

    The unique properties of gold especially in low temperature CO oxidation have been ascribed to a combination of various effects. In particular, particle sizes below a few nm and specific particle-support interactions have been shown to play important roles. On the contrary, recent reports revealed that monolithic nanoporous gold (npAu) prepared by leaching a less noble metal, such as Ag, out of the corresponding alloy can also exhibit remarkably high catalytic activity for CO oxidation, even though no support is present. Therefore, it was claimed to be a pure and unsupported gold catalyst. We investigated npAu with respect to its morphology, surface composition and catalytic properties. In particular, we studied the reaction kinetics for low temperature CO oxidation in detail taking mass transport limitation due to the porous structure of the material into account. Our results reveal that Ag, even if removed almost completely from the bulk, segregates to the surface resulting in surface concentrations of up to 10 at%. Our data suggest that this Ag plays a significant role in activation of molecular oxygen. Therefore, npAu should be considered as a bimetallic catalyst rather than a pure Au catalyst.

  12. Anomalies hematologiques au cours des accidents vasculaires ...

    African Journals Online (AJOL)

    Anomalies hematologiques au cours des accidents vasculaires cerebraux a Abidjan des (Cote d'Ivoire) ... Introduction: En Côte d'Ivoire, les accidents vasculaires cérébraux (AVC) sont de plus en ... The objective of the study was to report the hematological abnormalities in the stroke among black African patients in Abidjan.

  13. Didaktik des außerschulischen Lernens

    CERN Document Server

    Sauerborn, Petra

    2012-01-01

    Kernprobleme schulischer Bildung sind die zunehmenden Verluste an Realitäts- und Praxisbezug sowie die einseitige Betonung der fachwissenschaftlichen Kenntnisse. In jüngster Zeit werden insbesondere moderne didaktisch-methodische Konzepte näher diskutiert und praktiziert. So finden sich etwa die Stichwörter Handlungsorientierter Unterricht und Offener Unterricht in der fachdidaktischen Diskussion wieder. Eine wesentlich aktuellere Form stellt das außerschulische Lernen dar. Ein modernes pädagogisches Verständnis sieht den Unterricht heute nicht mehr als ausschließliche Tätigkeit des Lehrers an, sondern als Aktivität der Lernenden. Außerschulisches Lernen beschreibt die originale Begegnung im Unterricht außerhalb des Klassenzimmers. An außerschulischen Lernorten findet eine unmittelbare AuseinanderSetzung des Lernenden mit seiner räumlichen Umgebung statt. Charakteristisch sind hierbei vor allem die aktive(Mit-)Gestaltung sowie die eigenständige Wahrnehmung mehrperspektivischer Bildungsinhalte d...

  14. Melamine structures on the Au(111) surface

    NARCIS (Netherlands)

    Silly, Fabien; Shaw, Adam Q.; Castell, Martin R.; Briggs, G. A. D.; Mura, Manuela; Martsinovich, Natalia; Kantorovich, Lev

    2008-01-01

    We report on a joint experimental and theoretical study of the ordered structures of melamine molecules formed on the Au(111)-(22 x root 3) surface. Scanning tunneling microscopy (STM) images taken under UHV conditions reveal two distinct monolayers one of which has never been reported before on

  15. Surface structure of AU3Cu(001)

    DEFF Research Database (Denmark)

    Eckstein, G.A.; Maupai, S.; Dakkouri, A.S.

    1999-01-01

    The surface morphology, composition, and structure of Au3Cu(001) as determined by scanning tunneling microscopy and surface x-ray diffraction are presented. Atomic resolution STM images reveal distinctive geometric features. The analysis of the surface x-ray diffraction data provides clear evidence...... for the surface structure. [S0163-1829(99)04535-X]....

  16. Le CRDI au Pérou

    International Development Research Centre (IDRC) Digital Library (Canada)

    Arequipa. Trujillo. Chiclayo. Piura. Cuzco. Pucallpa. Iquitos. 914. ○ Tumbes. Quelques activités en cours. Voici quelques exemples des travaux de recherche appuyés par le CRDI au Pérou. □ Amélioration des pratiques agricoles pour lutter contre le paludisme. Financement : 500 400 CAD. Période visée : de 2012 à 2016.

  17. Measurement of identified π0 and inclusive photon second-harmonic parameter v2 and Implications for Direct Photon Production in VsNN=200 GeV Au+Au

    NARCIS (Netherlands)

    Peitzmann, T.

    2006-01-01

    The azimuthal distribution of identified π0 and inclusive photons has been measured in VsNN=200 GeV Au+Au collisions with the PHENIX experiment at the Relativistic Heavy-Ion Collider (RHIC). The second-harmonic parameter (v2) was measured to describe the observed anisotropy of the azimuthal

  18. Characterization of Au and Bimetallic PtAu Nanoparticles on PDDA-Graphene Sheets as Electrocatalysts for Formic Acid Oxidation

    Science.gov (United States)

    Yung, Tung-Yuan; Liu, Ting-Yu; Huang, Li-Ying; Wang, Kuan-Syun; Tzou, Huei-Ming; Chen, Po-Tuan; Chao, Chi-Yang; Liu, Ling-Kang

    2015-09-01

    Nanocomposite materials of the Au nanoparticles (Au/PDDA-G) and the bimetallic PtAu nanoparticles on poly-(diallyldimethylammonium chloride) (PDDA)-modified graphene sheets (PtAu/PDDA-G) were prepared with hydrothermal method at 90 °C for 24 h. The composite materials Au/PDDA-G and PtAu/PDDA-G were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) for exploring the structural characterization for the electrochemical catalysis. According to TEM results, the diameter of Au and bimetallic PtAu nanoparticles is about 20-50 and 5-10 nm, respectively. X-ray diffraction (XRD) results indicate that both of PtAu and Au nanoparticles exhibit the crystalline plane of (111), (200), (210), and (311). Furthermore, XRD data also show the 2°-3° difference between pristine graphene sheets and the PDDA-modified graphene sheets. For the catalytic activity tests of Au/PDDA-G and PtAu/PDDA-G, the mixture of 0.5 M aqueous H2SO4 and 0.5 M aqueous formic acid was used as model to evaluate the electrochemical characterizations. The catalytic activities of the novel bimetallic PtAu/graphene electrocatalyst would be anticipated to be superior to the previous electrocatalyst of the cubic Pt/graphene.

  19. Des institutions au service de villes sûres et inclusives au Venezuela

    International Development Research Centre (IDRC) Digital Library (Canada)

    Caracas, au Venezuela, est l'une des villes les plus violentes au monde; il s'y commet 122 homicides par tranche de 100 000 habitants. Selon les experts en violence urbaine, les inégalités sociales et la disparité des revenus sont étroitement liées à l'ampleur de la violence, mais cette théorie ne tient pas dans le cas ...

  20. Prévention de la violence chez les jeunes au Guatemala, au ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    La violence chez les jeunes, que ceux-ci en soient victimes ou responsables, est l'un des problèmes les plus importants en Amérique centrale. Ce projet de recherche servira à évaluer les stratégies actuelles de prévention de la violence chez les jeunes dans le triangle nord de la région, soit au Salvador, au Guatemala et ...

  1. Femmes, migration et droits au Mali et au Sénégal | CRDI - Centre ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    En Afrique de l'Ouest, notamment au Mali et au Sénégal, les migrations féminines concernent majoritairement les flux d'une part à l'intérieur des pays et d'autre part entre les pays. Du fait de la pauvreté, manque d'opportunités économiques et manque d'éducation, les jeunes filles migrantes risquent de subir des violations ...

  2. Baryon - baryon correlations in Au+Au collisions at sqrt(sNN)= 62 GeV and sqrt(sNN)= 200 GeV, measured in the STAR experiment at RHIC

    CERN Document Server

    Gos, H P

    2006-01-01

    Particle correlations at small relative velocities can be used to study the space-time evolution of hot and expanding system created in heavy ion collisions. Baryon and antibaryon source sizes extracted from baryon-baryon correlations complement the information deduced from the correlation studies of identical pions. Correlations of non-identical particles are sensitive also to the space-time asymmetry of their emission. High statistics data set of STAR experiment allows us to present the results of baryon-baryon correlation measurements at various centralities and energies, as well as to take carefully into account the particle identification probability and the fraction of primary baryons and antibaryons. Preliminary results show significant contribution of annihilation channel in baryon-antibaryon correlations.

  3. A reagentless amperometric immunosensor based on nano-au and ...

    African Journals Online (AJOL)

    In this paper, carboxyl-ferrocene (Fc-COOH) was explored to label alphafetoprotein antibody (anti-AFP), which was then mixed with AU nanoparticles (nano-Au) and multi-walled carbon nanotubes (MWCNTs) dispersed by chitosan (CS) to form the nano-Au/MWCNTs/anti-AFP-Fc chitosan composite. After that, the composite ...

  4. Au pair på ulige vilkår

    DEFF Research Database (Denmark)

    Christiansen, Connie Carøe

    2008-01-01

    Antallet af au pairs i Danmark fra Fillipinerne er steget markant i de seneste år. Mens danske myndigheder betragter au pair-ordningen som kulturudveksling blandt unge mennesker, ser fillipinske au pairs derimod den som en mulighed for at tjene penge så de kan forsørge deres egen familie i Fillip...

  5. The point-defect of carbon nanotubes anchoring Au nanoparticles

    DEFF Research Database (Denmark)

    Lv, Y. A.; Cui, Y. H.; Li, X. N.

    2010-01-01

    between Au clusters and CNTs by means of density functional theory calculations. Both experimental and theoretical studies show that point defects are the anchoring sites of Au nanoparticles. The mechanisms of enhanced bond between Au and CNTs via the point defects are explained by the analysis of density...

  6. Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S.

    Science.gov (United States)

    Tian, Zhimei; Cheng, Longjiu

    2016-01-14

    Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the "divide and protect" concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S(2)1P(6) configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters.

  7. The effect of Au amount on size uniformity of self-assembled Au nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S-H; Wang, D-C; Chen, G-Y; Chen, K-Y [Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Taiwan (China)

    2008-03-15

    The self-assembled fabrication of nanostructure, a dreaming approach in the area of fabrication engineering, is the ultimate goal of this research. A finding was proved through previous research that the size of the self-assembled gold nanoparticles could be controlled with the mole ratio between AuCl{sub 4}{sup -} and thiol. In this study, the moles of Au were fixed, only the moles of thiol were adjusted. Five different mole ratios of Au/S with their effect on size uniformity were investigated. The mole ratios were 1:1/16, 1:1/8, 1:1, 1:8, 1:16, respectively. The size distributions of the gold nanoparticles were analyzed by Mac-View analysis software. HR-TEM was used to derive images of self-assembled gold nanoparticles. The result reached was also the higher the mole ratio between AuCl{sub 4}{sup -} and thiol the bigger the self-assembled gold nanoparticles. Under the condition of moles of Au fixed, the most homogeneous nanoparticles in size distribution derived with the mole ratio of 1:1/8 between AuCl{sub 4}{sup -} and thiol. The obtained nanoparticles could be used, for example, in uniform surface nanofabrication, leading to the fabrication of ordered array of quantum dots.

  8. Effects of Excimer Irradiation Treatment on Thermocompression Au-Au Bonding

    Science.gov (United States)

    Naoko Unami,; Katsuyuki Sakuma,; Jun Mizuno,; Shuichi Shoji,

    2010-06-01

    We studied the feasibility of using vacuum ultraviolet (VUV) treatment as a surface improvement technique with Au-Au flip-chip bonding. For fine-pitch electrical interconnections in three-dimensional (3D) stack applications, robust and reliable bonding is desirable; in this case, surface modification treatment is needed before the bonding process. A VUV surface treatment was used to remove organic contaminants. Samples of electroplated Au pads were examined by X-ray photoelectron spectroscopy (XPS) to evaluate the chemical composition of the Au surfaces. The XPS results revealed that the carbon-based contaminants on the surface were removed by the VUV treatment. The shear strength of the bonded sample was also improved. The average shear strength of a bump with VUV treatment is 1.6 times larger than that of a bump without VUV treatment. Cross-sectional scanning electron microscopy (SEM) images of the bonded samples confirmed the absence of voids and cracks. The results show that VUV treatment has clear effects on Au-Au flip-chip bonding.

  9. Au(I/Au(III-catalyzed Sonogashira-type reactions of functionalized terminal alkynes with arylboronic acids under mild conditions

    Directory of Open Access Journals (Sweden)

    Deyun Qian

    2011-06-01

    Full Text Available A straightforward, efficient, and reliable redox catalyst system for the Au(I/Au(III-catalyzed Sonogashira cross-coupling reaction of functionalized terminal alkynes with arylboronic acids under mild conditions has been developed.

  10. From the Ternary Eu(Au/In)2 and EuAu4(Au/In)2 with Remarkable Au/In Distributions to a New Structure Type: The Gold-Rich Eu5Au16(Au/In)6 Structure.

    Science.gov (United States)

    Steinberg, Simon; Card, Nathan; Mudring, Anja-Verena

    2015-09-08

    The ternary Eu(Au/In)2 (EuAu(0.46)In(1.54(2))) (I), EuAu4(Au/In)2 (EuAu(4+x)In(2-x) with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu5Au16(Au/In)6 (Eu5Au(17.29)In(4.71(3))) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl4Mo2-type (tI14; I4/mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed of an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu5Au16(Au/In)6 (Eu5Au(17.29)In(4.71(3))) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu2-"EuAu4In2". The site preferences of the disordered Au/In positions in II were investigated for different hypothetical "EuAu4(Au/In)2" models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au-In contacts. A chemical bonding analysis on two "EuAu5In" and "EuAu4In2" models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.

  11. In-situ STM study of phosphate adsorption on Cu(111), Au(111) and Cu/Au(111) electrodes

    DEFF Research Database (Denmark)

    Schlaup, Christian; Horch, Sebastian

    2013-01-01

    The interaction of Cu(111), Au(111) and Cu-covered Au(111) electrodes with a neutral phosphate buffer solution has been studied by means of cyclic voltammetry (CV) and in situ electrochemical scanning tunneling microscopy (EC-STM). Under low potential conditions, both the Cu(111) and the Au(111) ...

  12. Tuning the kondo effect in thin Au films by depositing a thin layer of Au on molecular spin-dopants

    NARCIS (Netherlands)

    Ataç, Derya; Gang, T.; Yilmaz, M.D.; Bose, Saurabh; Lenferink, Aufrid T.M.; Otto, Cornelis; de Jong, Machiel Pieter; Huskens, Jurriaan; van der Wiel, Wilfred Gerard

    2013-01-01

    We report on the tuning of the Kondo effect in thin Au films containing a monolayer of cobalt(II) terpyridine complexes by altering the ligand structure around the Co2+ ions by depositing a thin Au capping layer on top of the monolayer on Au by magnetron sputtering (more energetic) and e-beam

  13. THE VALENCE OF AU IN AUTE2 AND AUSE STUDIED BY X-RAY-ABSORPTION SPECTROSCOPY

    NARCIS (Netherlands)

    ETTEMA, ARHF; STEGINK, TA; HAAS, C

    The gold compounds AuTe2 and AuSe contain Au atoms in two different chemical surroundings. In the literature these different coordinations have been associated with a difference in valency of the Au atoms. In this paper the occupation of the 5d shell in AuSe and AuTe2 is deduced from a study of the

  14. Thermal desorption of Au from W(001) surface

    CERN Document Server

    Blaszczyszyn, R; Godowski, P J

    2002-01-01

    Adsorption of Au on W(001) at 450 K up to multilayer structures was investigated. Temperature programmed desorption technique was used in determination of coverage dependent desorption energy (region up to one monolayer). Results were discussed in terms of competitive interactions of Au-Au and Au-W atoms. Simple procedure for prediction of faceting behavior on the interface, basing on the desorption data, was postulated. It was deduced that the Au/W(001) interface should not show faceting tendency after thermal treatment. (author)

  15. [Hyp-Au-Sn9(Hyp)3-Au-Sn9(Hyp)3-Au-Hyp]-: the longest intermetalloid chain compound of tin.

    Science.gov (United States)

    Binder, Mareike; Schrenk, Claudio; Block, Theresa; Pöttgen, Rainer; Schnepf, Andreas

    2017-10-12

    The reaction of the metalloid tin cluster [Sn10(Hyp)4]2- with (Ph3P)Au-SHyp (Hyp = Si(SiMe3)3) gave an intermetalloid cluster [Au3Sn18(Hyp)8]-1, which is the longest intermetalloid chain compound of tin to date. 1 shows a structural resemblance to binary AuSn phases, which is expected for intermetalloid clusters.

  16. Photoswitchable Faraday effect in EuS-Au nanosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, Akira; Nakanishi, Takayuki; Kitagawa, Yuichi; Fushimi, Koji; Hasegawa, Yasuchika [Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, North-13 West-8, Kita-ku, 060-8628, Sapporo (Japan)

    2016-01-15

    Effective photoswitchable europium sulfide nanocrystals with gold nanoparticles using dithiol (DDT: 1,10-decanedithiol) joint molecules, EuS-Au nanosystems, are demonstrated. The TEM image indicates the formation of EuS-Au nanosystems composed of cube-shaped EuS nanocrystals and spherical Au nanoparticles. Under visible-light irradiation, a drastic change of absorption band of EuS-Au nanosystems at around 600 nm was observed. The Faraday effects of EuS-Au nanosystems were estimated using magnetic circular dichroism (MCD) measurements. The effective change of the MCD spectra of EuS-Au nanosystems under visible-light irradiation was successfully observed at around 670 nm for the first time. The effective reversible changes in MCD spectra with the alternative irradiation cycles of visible light (>440 nm) and dark are also presented. The decrease rate of rotation angle at 670 nm of EuS-Au nanosystems is larger than that of absorbance. These results indicate that the effective change of MCD spectra of EuS-Au nanosystems would be dominated not only by a drastic change of absorption band related to enhanced LSPR of Au nanoparticles but also by specific interaction between EuS and Au in nanosystem under irradiation. Illustration of photoswitch and TEM image of EuS-Au nanosystems. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Introduction au numéro

    Directory of Open Access Journals (Sweden)

    Diane-Gabrielle Tremblay

    2005-07-01

    Full Text Available Depuis quelques années, le thème de l’économie sociale fait couler beaucoup d’encre au Québec, comme ailleurs. Ce numéro présente un bilan de l’économie sociale au Québec, coordonné par Jean-Marc Fontan et Denis Bussières. Toutefois, afin d’avoir un portrait plus global et une perspective théorique sur la question, Interventions économiques a sollicité un texte de Jacques Defourny, afin de compléter le dossier. En effet, l’économie sociale, les secteurs non-marchands, les services de proximi...

  18. Le fonds Gabriel Tarde au CHEVS

    OpenAIRE

    Louise Salmon

    2016-01-01

    Le fonds d’archives « Gabriel Tarde » déposé au CHEVS nous permet de mieux saisir l’érudit autodidacte que fut Gabriel Tarde. De la genèse de sa pensée à ses réseaux de sociabilité, de l’homme de sciences à l’homme de lettres, ses archives témoignent à la fois des usages et des enjeux des ressources archivistiques en histoire, mais elles permettent surtout un renouvellement du regard sur Gabriel Tarde en l’inscrivant au cœur de son temps que fut la fin du XIXème siècle.At the CHEVS in Paris, ...

  19. Identification of sup 186 Au. alpha. activity

    Energy Technology Data Exchange (ETDEWEB)

    Akovali, Y.A.; Toth, K.S. (Oak Ridge National Laboratory, Oak Ridge, TN (USA)); Bingham, C.R. (University of Tennessee, Knoxville, TN (USA) Oak Ridge National Laboratory, Oak Ridge, TN (USA)); Kassim, M.B.; Zhang, M. (University of Tennessee, Knoxville, TN (USA)); Carter, H.K. (UNISOR, Oak Ridge Associated Universities, Oak Ridge, TN (USA)); Hamilton, W.D. (Joint Institute for Heavy Ion Research, Holifield Heavy Ion Research Facility, Oak Ridge, TN (USA) Vanderbilt University, Nashville, TN (USA)); Kormicki, J. (Vanderbilt University, Nashville, TN (USA))

    1990-09-01

    With the use of an on-line isotope separator, the {alpha} activity of {sup 186}Au was identified for the first time. Only one {alpha} group ({ital E}{sub {alpha}}=4653{plus minus}15 keV) was observed. This transition was found not to be in coincidence with {gamma} rays so that it probably proceeds either to the {sup 182}Ir ground state or to a low-lying level whose deexciting {gamma} rays could not be detected. The {alpha}-decay branching was determined to be (8{plus minus}2){times}10{sup {minus}4}% from which a hindrance factor of 1.9{plus minus}0.9 was deduced. The 4653-keV {alpha} transition must therefore connect the 3{sup {minus}} {sup 186}Au ground state with a {sup 182}Ir level with the same spin and configuration.

  20. Au Based Nanocomposites Towards Plasmonic Applications

    Science.gov (United States)

    Panniello, A.; Curri, M. L.; Placido, T.; Reboud, V.; Kehagias, N.; Sotomayor Torres, C. M.; Mecerreyes, D.; Agostiano, A.; Striccoli, M.

    2010-06-01

    Incorporation of nano-sized metals in polymers can transfer their unique features to the host matrix, providing nanocomposite materials with improved optical, electric, magnetic and mechanical properties. In this work, colloidal Au nanorods have been incorporated into PMMA based random co-polymer, properly functionalized with amino groups and the optical and morphological properties of the resulting nanocomposite have been investigated by spectroscopic and AFM measurements. Au nanorods have demonstrated to preserve the plasmon absorption and to retain morphological features upon the incorporation, thus making the final metal modified polymer composite exploitable for the fabrication of plasmonic devices. The prepared nanocomposites have been then patterned by Nano Imprint Lithography technique in order to demonstrate the viability of the materials towards optical applications.

  1. Near-infrared-responsive, superparamagnetic Au@Co nanochains

    Directory of Open Access Journals (Sweden)

    Varadee Vittur

    2017-08-01

    Full Text Available This manuscript describes a new type of nanomaterial, namely superparamagnetic Au@Co nanochains with optical extinctions in the near infrared (NIR. The Au@Co nanochains were synthesized via a one-pot galvanic replacement route involving a redox-transmetalation process in aqueous medium, where Au salt was reduced to form Au shells on Co seed templates, affording hollow Au@Co nanochains. The Au shells serve not only as a protective coating for the Co nanochain cores, but also to give rise to the optical properties of these unique nanostructures. Importantly, these bifunctional, magneto-optical Au@Co nanochains combine the advantages of nanophotonics (extinction at ca. 900 nm and nanomagnetism (superparamagnetism and provide a potentially useful new nanoarchitecture for biomedical or catalytic applications that can benefit from both activation by light and manipulation using an external magnetic field.

  2. Tuning the collective switching behavior of azobenzene/Au hybrid materials: flexible versus rigid azobenzene backbones and Au(111) surfaces versus curved Au nanoparticles.

    Science.gov (United States)

    Liu, Chunyan; Zheng, Dong; Hu, Weigang; Zhu, Qiang; Tian, Ziqi; Zhao, Jun; Zhu, Yan; Ma, Jing

    2017-11-09

    The combination of photo-responsive azobenzene (AB) and biocompatible Au nanomaterials possesses potential applications in diverse fields such as biosensing and thermotherapy. To explore the influence of azobenzene moieties and Au substrates on the collective switching behavior, two different azobenzene derivatives (rigid biphenyl-controlled versus flexible alkoxyl chain-linked) and three different Au substrates (a planar Au(111) surface, curved Au 102 (SR) 44 and Au 25 (SR) 18 clusters) were chosen to form six Au@AB combinations. A reactive molecular dynamics (RMD) model considering both the torsion and inversion path was implemented to simulate the collective photo-induced cis-to-trans switching process of AB monolayers on Au substrates. The major driving force for isomerization is demonstrated to be the torsion of the C-N[double bond, length as m-dash]N-C dihedral angle, in addition to the minor contribution from an inversion pathway. The isomerization process can be divided into the preliminary conformation switching stage and the later relaxation stage, in which a gradual self-organization is observed for 40 ps. The Au substrate affects the packing structure of the AB monolayer, while the choice of different kinds of ABs tunes the intermolecular interaction in the monolayer. Flexible alkoxyl-linked F-AB may achieve much faster conversion on Au clusters than on the surface. For rigid biphenyl-based R-AB anchored on Au nanoparticles (AuNPs), a competitive torsion between the biphenyl and C-N[double bond, length as m-dash]N-C dihedral may delay the C-N[double bond, length as m-dash]N-C dihedral torsion and the following isomerization process. After the R-AB molecules were anchored on the Au(111) surface, the strong π-π stacking between biphenyl units accelerates the collective isomerization process. A curvature-dependent effect is observed for R-AB SAMs on different-sized substrates. The cooperation between functional AB monolayers and the Au substrate

  3. Les entreprises au Royaume-Uni

    OpenAIRE

    Appay, Beatrice

    1987-01-01

    This chapter of the book "Formations et emplois qualifiés. Les transformations dans le Bâtiment en France et au Royaume-Uni" analyses management strategies and organisational changes during a period of continuous crisis. The concept of cascading subcontracting (sous-traitance en cascade) introduced here encapsulates a new phenomenon observed simultaneously in the ever changing organisation of work between and within the firms. This is an important result of a research based on a 34 firm monog...

  4. la lutte contre le SIDA au Cameroun

    African Journals Online (AJOL)

    Chantel

    plurielles'). Tsala Tsala, J.-Ph. (2001). Medicina tradicional y sistema de salud publica en Camerun. Siso/Saude. 35: 48 -57. UNICEF, ONUSIDA, OMS (2001). Suivi et évaluation (au niveau local) de la prévention intégrée de la transmission mère-enfant du VIH dans les pays à revenus faibles.(doc ined. Projet 03/2001). 156.

  5. Le CRDI au Népal

    International Development Research Centre (IDRC) Digital Library (Canada)

    et visant à évaluer et à faire connaître les innovations en matière de production agricole, de transformation et de mise en marché. Le CRDI collabore avec le Fonds international de développement agricole à la mise sur pied de ce réseau, dont les membres sont reliés au moyen de technologies numériques. TE. K. G. U. R.

  6. Interstellar Pickup Ion Observations to 38 au

    Science.gov (United States)

    McComas, D. J.; Zirnstein, E. J.; Bzowski, M.; Elliott, H. A.; Randol, B.; Schwadron, N. A.; Sokół, J. M.; Szalay, J. R.; Olkin, C.; Spencer, J.; Stern, A.; Weaver, H.

    2017-11-01

    We provide the first direct observations of interstellar H+ and He+ pickup ions in the solar wind from 22 to 38 au. We use the Vasyliunas and Siscoe model functional form to quantify the pickup ion distributions, and while the fit parameters generally lie outside their physically expected ranges, this form allows fits that quantify variations in the pickup H+ properties with distance. By ∼20 au, the pickup ions already provide the dominant internal pressure in the solar wind. We determine the radial trends and extrapolate them to the termination shock at ∼90 au, where the pickup H+ to core solar wind density reaches ∼0.14. The pickup H+ temperature and thermal pressure increase from 22 to 38 au, indicating additional heating of the pickup ions. This produces very large extrapolated ratios of pickup H+ to solar wind temperature and pressure, and an extrapolated ratio of the pickup ion pressure to the solar wind dynamic pressure at the termination shock of ∼0.16. Such a large ratio has profound implications for moderating the termination shock and the overall outer heliospheric interaction. We also identify suprathermal tails in the H+ spectra and complex features in the He+ spectra, likely indicating variations in the pickup ion history and processing. Finally, we discover enhancements in both H+ and He+ populations just below their cutoff energies, which may be associated with enhanced local pickup. This study serves to document the release and serves as a citable reference of these pickup ion data for broad community use and analysis.

  7. Functionalized Au@Ag-Au nanoparticles as an optical and SERS dual probe for lateral flow sensing.

    Science.gov (United States)

    Bai, Tingting; Wang, Meng; Cao, Min; Zhang, Juan; Zhang, Kangzhen; Zhou, Ping; Liu, Zhengxia; Liu, Ying; Guo, Zhirui; Lu, Xiang

    2018-02-14

    Lateral flow assay strips (LFASs) with Au nanoparticles (NPs) have been widely used as a probe for biomarkers in point-of-care testing; however, there still remain challenges in detection sensitivity and quantitative analysis. In this study, we developed a surface-enhanced Raman scattering (SERS)-based LFAS for quantitative analysis of a biomarker in the low concentration range. Moreover, apart from conventional Au NPs, three other types of citrate-capped Au-Ag bimetallic NPs: Au core with Ag shell NPs (Au@Ag NPs), rattle-like Au core in Ag-Au shell NPs (Au@Ag-Au NPs) and Ag-Au NPs were prepared and functionalized, and their solution-based SERS activities were comprehensively studied by experimental measurement and theoretical analysis. The results clearly indicated that the citrate-capped Au@Ag-Au NPs exhibited the highest SERS activity among the probes tested. Au@Ag-Au NPs were used as both optical and SERS probes in a SERS-based LFAS. In the presence of the analyte at high concentrations, a purple color appeared in the test zone. Highly sensitive and quantitative analysis was realized by measurement of SERS signals from the test lines. One of the most specific markers for cardiac injury, cardiac troponin I (cTnI), was chosen as the detection model. The detection limit of the SERS-based LFAS for cardiac troponin I was 0.09 ng/mL, lowered by nearly 50 times compared with visual results, and could be further lowered by optimization. These results demonstrated that the SERS-based LFAS using citrate-capped Au@Ag-Au NPs as probes can be a powerful tool for highly sensitive and quantitative detection of biomarkers. Graphical abstract A surface-enhanced Raman scattering (SERS)-based lateral flow assay strip using rattle-like Au core in Ag-Au shell (Au@Ag-Au) nanoparticles as probes was developed for quantitative analysis of a biomarker, with a detection limit nearly 50 times lower than that of visual assessment. C control line, T test line.

  8. A photoresponsive Au25 nanocluster protected by azobenzene derivative thiolates

    Science.gov (United States)

    Negishi, Yuichi; Kamimura, Ukyo; Ide, Mao; Hirayama, Michiyo

    2012-06-01

    An Au25 cluster protected by azobenzene derivative thiolates (S-Az) ([Au25(S-Az)18]-) was synthesized with the aim of producing a photoresponsive Au25 cluster. The matrix-assisted laser desorption/ionization mass spectrum of the product revealed that [Au25(S-Az)18]- was synthesized in high purity. Optical absorption spectra of [Au25(S-Az)18]- obtained before and after photoirradiation suggest that the azobenzenes in the ligands of Au25(S-Az)18 isomerize with an efficiency of nearly 100%, both from the trans to cis conformation and from the cis to trans conformation. Furthermore, the redox potential and optical absorption of Au25(S-Az)18 were found to change reversibly due to photoisomerization of azobenzenes.An Au25 cluster protected by azobenzene derivative thiolates (S-Az) ([Au25(S-Az)18]-) was synthesized with the aim of producing a photoresponsive Au25 cluster. The matrix-assisted laser desorption/ionization mass spectrum of the product revealed that [Au25(S-Az)18]- was synthesized in high purity. Optical absorption spectra of [Au25(S-Az)18]- obtained before and after photoirradiation suggest that the azobenzenes in the ligands of Au25(S-Az)18 isomerize with an efficiency of nearly 100%, both from the trans to cis conformation and from the cis to trans conformation. Furthermore, the redox potential and optical absorption of Au25(S-Az)18 were found to change reversibly due to photoisomerization of azobenzenes. Electronic supplementary information (ESI) available: Details of the experimental procedure and characterization of the products. See DOI: 10.1039/c2nr30830d

  9. Photocatalysis enhancement of Au/BFO nanoparticles using plasmon resonance of Au NPs

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Cai, Zhongyang; Ma, Xueming, E-mail: xmma@phy.ecnu.edu.cn

    2015-12-15

    BiFeO{sub 3} (BFO) nanoparticles was synthesized via sol–gel technique, and successfully loaded with small sizes of gold nanoparticles (Au NPs) by impregnation-reduction method to extremely enhance the BFO photocatalytic activity. The obviously stronger optical absorption of Au/BFO observed from the UV–vis diffuse reflectance spectrum confirmed that the surface plasmon resonance (SPR) effect occured on the surface of Au NPs. And the surface plasmon-induced localized electric field could allow the formation of electron/hole pairs in the near surface region of BFO which can migrate to the surface without undergoing electron/hole (e{sup −}/h{sup +}) pair recombination. The more electrons and holes formed, the more ·OH will be generated to decompose the CR solution. When the gold loading in Au/BFO nanoparticles is 3.36 wt%, the obtained Au/BFO catalyst exhibits best photocatalytic activity evaluated by photocatalysis degradation of Congo red (CR) solution under the visible light irradiation.

  10. Virus-templated Au and Au/Pt Core/shell Nanowires and Their Electrocatalytic Activitives for Fuel Cell Applications

    Science.gov (United States)

    LEE, YOUJIN; KIM, JUNHYUNG; YUN, DONG SOO; NAM, YOON SUNG; SHAO-HORN, YANG; BELCHER, ANGELA M.

    2014-01-01

    A facile synthetic route was developed to make Au nanowires (NWs) from surfactant-mediated bio-mineralization of a genetically engineered M13 phage with specific Au binding peptides. From the selective interaction between Au binding M13 phage and Au ions in aqueous solution, Au NWs with uniform diameter were synthesized at room temperature with yields greater than 98 % without the need for size selection. The diameters of Au NWs were controlled from 10 nm to 50 nm. The Au NWs were found to be active for electrocatalytic oxidation of CO molecules for all sizes, where the activity was highly dependent on the surface facets of Au NWs. This low-temperature high yield method of preparing Au NWs was further extended to the synthesis of Au/Pt core/shell NWs with controlled coverage of Pt shell layers. Electro-catalytic studies of ethanol oxidation with different Pt loading showed enhanced activity relative to a commercial supported Pt catalyst, indicative of the dual functionality of Pt for the ethanol oxidation and Au for the anti-poisoning component of Pt. These new one-dimensional noble metal NWs with controlled compositions could facilitate the design of new alloy materials with tunable properties. PMID:24910712

  11. Au 38 (SPh) 24 : Au 38 Protected with Aromatic Thiolate Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Rambukwella, Milan; Burrage, Shayna; Neubrander, Marie; Baseggio, Oscar; Aprà, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

    2017-03-21

    Au38(SR)24 is one of the most extensively investigated gold nanomolecules along with Au25(SR)18 and Au144(SR)60. However, so far it has only been prepared using aliphatic-like ligands, where R = –SC6H13, -SC12H25 and –SCH2CH2Ph. Au38(SCH2CH2Ph)24 when reacted with HSPh undergoes core-size conversion to Au36(SPh)24, and existing literature suggest that Au38(SPh)24 cannot be synthesized. Here, contrary to prevailing knowledge, we demonstrate that Au38(SPh)24 can be prepared if the ligand exchanged conditions are optimized, without any formation of Au36(SPh)24. Conclusive evidence is presented in the form of MALDI-MS, ESI-MS characterization, and optical spectra of Au38(SPh)24 in a solid glass form showing distinct differences from that of Au38(S-aliphatic)24. Theoretical analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au38(SPh)24 is comparable to that of its aliphatic analogues, but results from different physical origins, with a significant component of ligand-ligand attractive interactions.

  12. Au99(SPh)42 nanomolecules: aromatic thiolate ligand induced conversion of Au144(SCH2CH2Ph)60.

    Science.gov (United States)

    Nimmala, Praneeth Reddy; Dass, Amala

    2014-12-10

    A new aromatic thiolate protected gold nanomolecule Au99(SPh)42 has been synthesized by reacting the highly stable Au144(SCH2CH2Ph)60 with thiophenol, HSPh. The ubiquitous Au144(SR)60 is known for its high stability even at elevated temperature and in the presence of excess thiol. This report demonstrates for the first time the reactivity of the Au144(SCH2CH2Ph)60 with thiophenol to form a different 99-Au atom species. The resulting Au99(SPh)42 compound, however, is unreactive and highly stable in the presence of excess aromatic thiol. The molecular formula of the title compound is determined by high resolution electrospray mass spectrometry (ESI-MS) and confirmed by the preparation of the 99-atom nanomolecule using two ligands, namely, Au99(SPh)42 and Au99(SPh-OMe)42. This mass spectrometry study is an unprecedented advance in nanoparticle reaction monitoring, in studying the 144-atom to 99-atom size evolution at such high m/z (∼12k) and resolution. The optical and electrochemical properties of Au99(SPh)42 are reported. Other substituents on the phenyl group, HS-Ph-X, where X = -F, -CH3, -OCH3, also show the Au144 to Au99 core size conversion, suggesting minimal electronic effects for these substituents. Control experiments were conducted by reacting Au144(SCH2CH2Ph)60 with HS-(CH2)n-Ph (where n = 1 and 2), bulky ligands like adamantanethiol and cyclohexanethiol. It was observed that conversion of Au144 to Au99 occurs only when the phenyl group is directly attached to the thiol, suggesting that the formation of a 99-atom species is largely influenced by aromaticity of the ligand and less so on the bulkiness of the ligand.

  13. Charge transport through O-deficient Au-MgO-Au junctions

    KAUST Repository

    Fadlallah, M. M.

    2009-12-29

    Metal-oxide heterostructures have been attracting considerable attention in recent years due to various technological applications. We present results of electronic structure and transport calculations for the Au-MgO-Au (metal-insulator-metal) heterostructure based on density-functional theory and the nonequilibrium Green’s functions method. The dependence of the conductance of the heterostructure on the thickness of the MgO interlayer and the interface spacing is studied. In addition, we address the effects of O vacancies. We observe deviations from an exponentially suppressed conductance with growing interlayer thickness caused by Au-O chemical bonds. Electronic states tracing back to O vacancies can increase the conductance. Furthermore, this effect can be enhanced by enlarging the interface spacing as the vacancy induced Mg states are shifted toward the Fermi energy.

  14. Strange particle correlations measured by the Star experiment in ultra-relativistic heavy ion collisions a RHIC; Etude des correlations de particules etranges mesurees par l'experience STAR dans les collisions d'ions lourds ultra-relativistes au RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Renault, G

    2004-09-01

    Non-identical correlation functions allow to study the space-time evolution of the source of particles formed in ultra-relativistic heavy ion collisions. The STAR experiment is dedicated to probe the formation of a new state of nuclear matter called Quark Gluon Plasma. The proton - lambda correlation function is supposed to be more sensitive to bigger source sizes than the proton - proton because of the absence of the final state Coulomb interaction. In this thesis, proton - lambda, anti-proton - anti-lambda, anti-proton - lambda and proton - anti-lambda correlation functions are studied in Au+Au collisions at {radical}S{sub NN} = 200 GeV using an analytical model. The proton - lambda and anti-proton - anti-lambda correlation functions exhibit the same behavior as in previous measurements. The anti-proton - lambda and proton - anti-lambda correlation functions, measured for the first time, show a very strong signal corresponding to the baryon - anti-baryon annihilation channel. Parameterizing the correlation functions has allowed to characterize final state interactions. (author)

  15. Coût des soins de santé attribuables au tabagisme au Cambodge ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Au Cambodge, l'incidence de la tuberculose et du tabagisme est élevée de sorte que le coût du tabagisme comprendra aussi le coût des décès " supplémentaires " occasionnés par la tuberculose liée au tabagisme. Dans ce pays, les systèmes d'information sur la santé ne sont ni rigoureux, ni fiables. Par conséquent, on ne ...

  16. Relativistic multireference many-body perturbation theory calculations on Au64+ - Au69+ ions

    Energy Technology Data Exchange (ETDEWEB)

    Vilkas, M J; Ishikawa, Y; Trabert, E

    2006-03-31

    Many-body perturbation theory (MBPT) calculations are an adequate tool for the description of the structure of highly charged multi-electron ions and for the analysis of their spectra. They demonstrate this by way of a re-investigation of n=3, {Delta}n=0 transitions in the EUV spectra of Na-, Mg-, Al-like, and Si-like ions of Au that have been obtained previously by heavy-ion accelerator based beam-foil spectroscopy. They discuss the evidence and propose several revisions on the basis of the multi-reference many-body perturbation theory calculations of Ne- through P-like ions of Au.

  17. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation

    Science.gov (United States)

    Hsu, Chiajen; Huang, Chienwen; Hao, Yaowu; Liu, Fuqiang

    2013-03-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies.

  18. Conductive Au nanowires regulated by silk fibroin nanofibers

    Science.gov (United States)

    Dong, Bo-Ju; Lu, Qiang

    2014-03-01

    Conductive Au-biopolymer composites have promising applications in tissue engineering such as nerve tissue regeneration. In this study, silk fibroin nanofibers were formed in aqueous solution by regulating silk self-assembly process and then used as template for Au nanowire fabrication. We performed the synthesis of Au seeds by repeating the seeding cycles for several times in order to increase the density of Au seeds on the nanofibers. After electroless plating, densely decorated Au seeds grew into irregularly shaped particles following silk nanofiber to fill the gaps between particles and finally form uniform continuous nanowires. The conductive property of the Au-silk fibroin nanowires was studied with current-voltage ( I-V) measurement. A typical ohmic behavior was observed, which highlighted their potential applications in nerve tissue regeneration.

  19. Lateral spreading of Au contacts on InP

    Science.gov (United States)

    Fatemi, Navid S.; Weizer, Victor G.

    1990-01-01

    The contact spreading phenomenon observed when small area Au contacts on InP are annealed at temperatures above about 400 C was investigated. It was found that the rapid lateral expansion of the contact metallization which consumes large quantities of InP during growth is closely related to the third stage in the series of solid state reactions that occur between InP and Au, i.e., to the Au3In-to-Au9In4 transition. Detailed descriptions are presented of both the spreading process and the Au3In-to-Au9In4 transition along with arguments that the two processes are manifestations of the same basic phenomenon.

  20. Caroline Datchary, La Dispersion au travail

    Directory of Open Access Journals (Sweden)

    Guillaume Lecoeur

    2012-12-01

    Full Text Available Impression de ne pas pouvoir faire totalement son travail, insatisfaction, Trouble Musculo- Squelettique, mais aussi sentiment d’efficacité, d’excitation et parfois de plénitude. Ces sensations, bien qu’ambivalentes, ont néanmoins un point commun selon Caroline Datchary : elles sont engendrées par des situations de « dispersion au travail ». Mutation du travail oblige, les toujours Nouvelles Technologies de l’Information et de la Communication (NTIC ont fait leur apparition, la pression conc...

  1. Quantum interference effects in nanostructured Au

    Science.gov (United States)

    Pratumpong, P.; Cochrane, R. F.; Evans, S. D.; Johnson, S.; Howson, M. A.

    2002-11-01

    We present results on the magnetoresistance and temperature dependence of the resistivity for nanostructured Au produced by chemical means. The magnetoresistance was typical of highly disordered metals exhibiting quantum interference effects. We fitted the data and were able to determine the spin-orbit scattering relaxation time to be 10-12 s and we found the inelastic scattering time at 10 K to be 10-11 s. The inelastic scattering rate varied as T3 between 4 and 20 K, which is typical for electron-phonon scattering in disordered metals.

  2. Quantum interference effects in nanostructured Au

    CERN Document Server

    Pratumpong, P; Evans, S D; Johnson, S; Howson, M A

    2002-01-01

    We present results on the magnetoresistance and temperature dependence of the resistivity for nanostructured Au produced by chemical means. The magnetoresistance was typical of highly disordered metals exhibiting quantum interference effects. We fitted the data and were able to determine the spin-orbit scattering relaxation time to be 10 sup - sup 1 sup 2 s and we found the inelastic scattering time at 10 K to be 10 sup - sup 1 sup 1 s. The inelastic scattering rate varied as T sup 3 between 4 and 20 K, which is typical for electron-phonon scattering in disordered metals.

  3. Quantum interference effects in nanostructured Au

    Energy Technology Data Exchange (ETDEWEB)

    Pratumpong, P [Department of Materials, University of Leeds, Leeds LS2 9JT (United Kingdom); Cochrane, R F [Department of Materials, University of Leeds, Leeds LS2 9JT (United Kingdom); Evans, S D [Department of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Johnson, S [Department of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Howson, M A [Department of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2002-11-18

    We present results on the magnetoresistance and temperature dependence of the resistivity for nanostructured Au produced by chemical means. The magnetoresistance was typical of highly disordered metals exhibiting quantum interference effects. We fitted the data and were able to determine the spin-orbit scattering relaxation time to be 10{sup -12} s and we found the inelastic scattering time at 10 K to be 10{sup -11} s. The inelastic scattering rate varied as T{sup 3} between 4 and 20 K, which is typical for electron-phonon scattering in disordered metals.

  4. Phase behavior of Au and Pt surfaces

    DEFF Research Database (Denmark)

    Grübel, G.; Gibbs, D.; Zehner, D.M.

    1993-01-01

    We summarize the results of X-ray scattering studies of the Au(001) and Pt(001) surfaces between 300 K and their respective bulk melting temperatures (T(m)). Both surfaces exhibit three distinct structural phases. At high temperatures (0.88T(m) surfaces are disordered. The Pt(001......) surface is rough. At a temperature of T/T(m) almost-equal-to 0.88 there are reversible phase transformations to incommensurate, corrugated-hexagonal phases. Below T/T(m) almost-equal-to 0.8 hexagonal domains rotate with respect to the substrate orientation. In Pt, the rotational transformation...

  5. Caracterisation Du Regime Alimentaire Des Personnes Agees Au ...

    African Journals Online (AJOL)

    L'étude s'est déroulée dans la ville de Cotonou au cours de la période transitionnelle entre la soudure et l'abondance alimentaire (octobre-novembre), avec 225 hommes et femmes ayant au moins 60 ans, apparemment en bonne santé mentale, sélectionnés au hasard par la méthode d'échantillonnage en grappes à 3 ...

  6. Photosynthetic electron transport system promotes synthesis of Au-nanoparticles.

    Directory of Open Access Journals (Sweden)

    Nisha Shabnam

    Full Text Available In this communication, a novel, green, efficient and economically viable light mediated protocol for generation of Au-nanoparticles using most vital organelle, chloroplasts, of the plant system is portrayed. Thylakoids/chloroplasts isolated from Potamogeton nodosus (an aquatic plant and Spinacia oleracea (a terrestrial plant turned Au³⁺ solutions purple in presence of light of 600 µmol m⁻² s⁻¹ photon flux density (PFD and the purple coloration intensified with time. UV-Vis spectra of these purple colored solutions showed absorption peak at ∼545 nm which is known to arise due to surface plasmon oscillations specific to Au-nanoparticles. However, thylakoids/chloroplasts did not alter color of Au³⁺ solutions in dark. These results clearly demonstrated that photosynthetic electron transport can reduce Au³⁺ to Au⁰ which nucleate to form Au-nanoparticles in presence of light. Transmission electron microscopic studies revealed that Au-nanoparticles generated by light driven photosynthetic electron transport system of thylakoids/chloroplasts were in range of 5-20 nm. Selected area electron diffraction and powder X-ray diffraction indicated crystalline nature of these nanoparticles. Energy dispersive X-ray confirmed that these nanoparticles were composed of Au. To confirm the potential of light driven photosynthetic electron transport in generation of Au-nanoparticles, thylakoids/chloroplasts were tested for their efficacy to generate Au-nanoparticles in presence of light of PFD ranging from 60 to 600 µmol m⁻² s⁻¹. The capacity of thylakoids/chloroplasts to generate Au-nanoparticles increased remarkably with increase in PFD, which further clearly demonstrated potential of light driven photosynthetic electron transport in reduction of Au³⁺ to Au⁰ to form nanoparticles. The light driven donation of electrons to metal ions by thylakoids/chloroplasts can be exploited for large scale production of nanoparticles.

  7. principales écologies rizicoles au Burkina Faso

    African Journals Online (AJOL)

    Un inventaire des nématodes parasites du riz au Burkina Faso a été réalisé au cours de la campagne agricole humide 2016-2017. Ce travail de recherche vise à étudier la prévalence et l'abondance des principaux nématodes parasites associés au riz dans les 3 principales écologies rizicoles que sont la riziculture pluviale ...

  8. Complications liees a la fibroscopie bronchique au CHU Sylvanus ...

    African Journals Online (AJOL)

    Durant une période allant de 1er février 2012 au 31 janvier 2013, les données portant sur les incidents ou accidents survenus au cours de la fibroscopie bronchique (au cours de la prémédication, pendant l'examen et les 7 jours suivants) ont étés collectées chez les patients ayant subi une fibroscopie bronchique dans le ...

  9. Acteurs et strategies face aux nouveaux defis securitaires au Benin ...

    African Journals Online (AJOL)

    De même, de nouveaux acteurs dont la communauté des chasseurs au centre et au nord du Bénin, les adeptes du ''Zangbéto'' au sud, les ONG et autres sont nés avec leurs stratégies. Mots clés: acteurs, stratégies, sécurité, développement. English Abstract. Although the security constitute the essential condition for all ...

  10. Plasmonic welding of hybrid Au-ZnO nanostructure

    Science.gov (United States)

    Chen, Z. Y.; Yang, H. B.; Ghosh, P.; Li, Q.; Qiu, M.

    2017-06-01

    We report that 532 nm CW laser can be used to obtain non-wetting metal-semiconductor (Au-ZnO) Schottky heterojunctions by plasmonic welding. Single crystal Au and n-type ZnO nanowires are placed on gold (Au) and titanium (Ti) electrodes, respectively, and the junction welding is realized. The current-voltage (I-V) characteristic curve of the single Schottky rectifier is also measured.

  11. Resistance aux antibiotiques des bacteries isolees en 2009 au ...

    African Journals Online (AJOL)

    Objectif : Contribuer à la surveillance de la résistance bactérienne aux antibiotiques au Togo en étudiant la résistance aux antibiotiques des bactéries. Méthode Il s'agit d'une étude descriptive transversale portant sur les comptes rendus des antibiogrammes réalisés du 1er janvier au 31 décembre 2009 au Laboratoire de ...

  12. Conjugated electrical properties of Au nanoparticle–polyaniline network

    Science.gov (United States)

    Usami, Yuki; Otsuka, Yoichi; Naitoh, Yasuhisa; Matsumoto, Takuya

    2017-12-01

    We investigated the electrical properties of a two-dimensional (2D) network consisting of multiple Au nanoparticles (AuNPs) and self-doped polyaniline sulfonate (SPAN). Nonlinear current–voltage (I–V) characteristics with wide variations were observed in the networks. The temperature dependence of the I–V characteristics exhibited a short localization length, suggesting conjugated electronic properties of the AuNP–SPAN network. This result provides a new direction for network-based molecular electronic devices.

  13. Experimental evidence for electron localization on Au upon photo-activation of Au/anatase catalysts

    NARCIS (Netherlands)

    Carneiro, J.T.; Carneiro, Joana T.; Savenije, Tom J.; Mul, Guido

    2009-01-01

    Time resolved microwave conductivity (TRMC) measurements show that the presence of Au on anatase Hombikat UV100 significantly reduces the lifetime of mobile electrons formed by photo-excitation of this photocatalyst at 300 nm, providing evidence for the widely acclaimed electron localization effect

  14. Azimuthal anisotropy in S+Au reactions at 200 A GeV

    NARCIS (Netherlands)

    Aggarwal, MM; Angelis, ALS; Antonenko, [No Value; Awes, TC; Badyal, SK; Barlag, C; Bhalla, KB; Bhatia, VS; Blume, C; Bock, D; Bohne, EM; Bucher, D; Buijs, A; Chattopadhyay, S; Claussen, A; Clewing, G; Das, AC; Devanand, [No Value; Donni, P; Durieux, E; Majumdar, MRD; Foka, P; Fokin, S; Ganti, MS; Garpman, S; Geurts, F; Ghosh, TK; Glasow, R; Gupta, SK; Gustafsson, H.A.; Gutbrod, HH; Hartig, M; Holker, G; Ippolitov, M; Izycki, M; Kachroo, S; Kalechofsky, H; Kamermans, R; Kampert, KH; Karadjev, K; Kolb, BW; Langbein, [No Value; Langheinrich, J; Lebedev, A; Löhner, Herbert; Loknathan, S; Manko, [No Value; Martin, M; Mittra, IS; Mookerjee, S; Naef, H; Nayak, SK; Nayak, TK; Nikolaev, S; Nystrand, J; Obenshain, FE; Oskarsson, A; Otterlund, [No Value; Peitzmann, T; Plasil, F; Purschke, M; Raniwala, S; Rao, NK; Rosselet, L; Roters, B; Rubio, JM; Saini, S; Sambyal, S; Santo, R; Siemiarczuk, T; Siemssen, RH; Sinha, BC; Slegt, S; Soderstrom, K; Solomey, N; Sorensen, SP; Stefanek, G; Steinhaeuser, P; Stenlund, E; Ster, A; Stuken, D; Trivedi, MD; Twenhoefel, C; VanEijndhoven, N; VanHeeringen, WH; Vinogradov, A; Viyogi, YP; Young, GR

    1997-01-01

    Azimuthal correlations of photons produced at mid-rapidity in 200 A GeV S + Au collisions have been studied using a preshower photon multiplicity detector in the WA93 experiment. The Fourier expansion method has been employed to estimate the event plane via the anisotropy of the event as a function

  15. Identified hadron production in $\\sqrt {s}= 130$ GeV Au–Au ...

    Indian Academy of Sciences (India)

    ... Pramana – Journal of Physics; Volume 60; Issue 5. Identified hadron production in s = 130 GeV Au–Au collisions at relativistic heavy-ion collider. Julia Velkovska. Volume 60 Issue 5 May 2003 pp 1011-1015 ... Author Affiliations. Julia Velkovska1. Brookhaven National Laboratory, Bldg. 510C, Upton, NY 11973, USA ...

  16. Divided café-au-lait macule of the mouth.

    Science.gov (United States)

    Sergay, Amanda; Silverberg, Nanette B

    2007-05-01

    We describe a 4-year-old, otherwise healthy boy with a congenital history of a perioral and labial segmental café-au-lait macule, who was noted to have unilateral localized gingival hyperpigmentation that aligned with the café-au-lait macule. This case is highly illustrative of the embryologic timing of the genetic event locally, which leads to café-au-lait type hyperpigmentation. Because the facial features and the ectoderm overlying the facial muscles develop around the third to fourth week of gestation, the distribution of this café-au-lait macule suggests development at the same time.

  17. The self assembly of thymine at Au(110)/liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Molina Contreras, J.R. [Departamento de Ingenieria Electrica y Electronica, Instituto Tecnologico de Aguascalientes, Mexico (Mexico); Smith, C.I.; Bowfield, A.; Weightman, P. [Physics Department, University of Liverpool (United Kingdom); Tillner, F. [Fachbereich Physik, Universitaet Konstanz (Germany)

    2012-06-15

    We show that thymine self-assembles into an ordered structure when adsorbed at a Au(110)/liquid interface. Reflection anisotropy spectroscopy (RAS) shows that as found for cytosine and adenine the adsorbed thymine molecules are oriented essentially vertically on the Au(110) surface with the molecule aligned along one of the principal axes of the Au(110) surface. Simulations of the RA spectra to an empirical model indicates that as found for adsorbed cytosine and adenine, thymine is aligned along the [1 anti 10] direction on the Au(110) surface. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Design of Au/SPIO composite nanoparticle for facile and biocompatible surface functionalization via Au-S bond

    Energy Technology Data Exchange (ETDEWEB)

    Seino, Satoshi, E-mail: seino@mit.eng.osaka-u.ac.jp; Shibata, Yujin; Yamanaka, Masayuki; Nakagawa, Takashi [Osaka University, Graduate School of Engineering (Japan); Mukai, Yohei; Nakagawa, Shinsaku [Osaka University, Graduate School of Pharmaceutical Sciences and Center for Advanced Medical Engineering and Informatics (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

    2013-01-15

    Immobilization of Au nanoparticles on super-paramagnetic iron-oxide (SPIO) enables facile and biocompatible surface functionalization via Au-S bond. Au/SPIO composite nanoparticle is easily modified by thiol-modified polyethylene glycol (PEG-SH), and they are successfully applied on MR tumor imaging. However, its large hydrodynamic size ({approx}150 nm) still causes the accumulation to liver in vivo. In this study, we controlled the hydrodynamic size of Au/SPIO by testing different raw SPIOs and stabilizing polymers. As the best candidate, Au/Molday-ION which was synthesized from Molday-ION and polyvinyl alcohol comprised the hydrodynamic size of 56 nm. Moreover, PEGylated Au/Molday-ION showed excellent dispersibility in blood serum, with the hydrodynamic size of 65 nm. This surface functionalization strategy is effective for the constructions of magnetic nanocarriers for in vivo applications.

  19. Neutral meson production in d+Au and p+p collisions at √sNN = 200 GeV in STAR

    NARCIS (Netherlands)

    Grebenyuk, O.

    2007-01-01

    The high centre-of-mass energy of 200 GeV available at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven opens up the hard scattering regime in heavy-ion collisions. Hard particles at large transverse momentum originate from the early stage of the interaction and therefore probe the medium

  20. Approche historiographique des pratiques sportives au Cameroun

    Directory of Open Access Journals (Sweden)

    Biwole M. Claude Emmanuel Abolo

    2016-01-01

    En 50 ans d'indépendance, le sport camerounais a beaucoup évolué. De 11 en 1970, les fédérations sportives sont passées à plus de 40 aujourd'hui et les titres, trophées et médailles ne se comptent plus depuis lors. Le Cameroun est devenu progressivement une nation où le sport compte et où l'exploit sportif n'est plus méprisé, rejeté, voire vilipendé. Hier assimilés à des brutes épaisses, les sportifs sont aujourd'hui admirés et adulés. Finie l'image négative de marginaux qui leur collait au corps : finis les sous-entendus ridicules où ils étaient classés au bas de l'échelle sociale, juste bons pour bander les muscles et réaliser des performances. C'est cela la plus grande victoire du sport camerounais en 50 ans d'existence. Il a réussi à faire l'unanimité et les performances des sportifs devenues pour toute la nation un modèle, une référence et un réel motif de fierté.

  1. IMAGING PROMINENCE ERUPTIONS OUT TO 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Brian E.; Howard, Russell A.; Linton, Mark G., E-mail: brian.wood@nrl.navy.mil [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States)

    2016-01-10

    Views of two bright prominence eruptions trackable all the way to 1 AU are here presented, using the heliospheric imagers on the Solar TErrestrial RElations Observatory (STEREO) spacecraft. The two events first erupted from the Sun on 2011 June 7 and 2012 August 31, respectively. Only these two examples of clear prominence eruptions observable this far from the Sun could be found in the STEREO image database, emphasizing the rarity of prominence eruptions this persistently bright. For the 2011 June event, a time-dependent 3D reconstruction of the prominence structure is made using point-by-point triangulation. This is not possible for the August event due to a poor viewing geometry. Unlike the coronal mass ejection (CME) that accompanies it, the 2011 June prominence exhibits little deceleration from the Sun to 1 AU, as a consequence moving upwards within the CME. This demonstrates that prominences are not necessarily tied to the CME's magnetic structure far from the Sun. A mathematical framework is developed for describing the degree of self-similarity for the prominence's expansion away from the Sun. This analysis suggests only modest deviations from self-similar expansion, but close to the Sun the prominence expands radially somewhat more rapidly than self-similarity would predict.

  2. Apprentissage administratif : L'apprentissage au CERN

    CERN Multimedia

    2004-01-01

    APPRENTISSAGE ADMINISTRATIF FORMATION ET DEVELOPPEMENT HR/PMD/RCC L'APPRENTISSAGE AU CERN pour les professions d'employé(e) de commerce et d'assistant(e) en information documentaire L'apprentissage au CERN est régi par les lois, règlements et contrats en vigueur dans le Canton de Genève. En cas de réussite à l'examen de fin d'apprentissage, les apprentis obtiennent le Certificat Fédéral de Capacité Suisse (CFC). 1 place est offerte pour la formation d'employé(e) de commerce 2 places sont offertes pour la formation d'assistant(e) en information documentaire L'apprentissage dure 3 ans. Minima requis pour faire acte de candidature : • avoir terminé la scolarité obligatoire • être ressortissant d'un pays membre du CERN (Allemagne, Autriche, Belgique, Bulgarie, Danemark, Espagne,Finlande, France, Grèce, Hongrie, Italie, Norvège...

  3. Mesomorphic Lamella Rolling of Au in Vacuum

    Directory of Open Access Journals (Sweden)

    Chen Shuei-Yuan

    2009-01-01

    Full Text Available Abstract Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs or alternatively in the form of multiple-walled tubes (MWTs having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241–0.192 nm and the nearest neighbor distance (ca. 0.74–0.55 nm of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458–0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon–hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration.

  4. Hollow Au@Pd and Au@Pt core-shell nanoparticles as electrocatalysts for ethanol oxidation reactions

    KAUST Repository

    Song, Hyon Min

    2012-09-27

    Hybrid alloys among gold, palladium and platinum become a new category of catalysts primarily due to their enhanced catalytic effects. Enhancement means not only their effectiveness, but also their uniqueness as catalysts for the reactions that individual metals may not catalyze. Here, preparation of hollow Au@Pd and Au@Pt core-shell nanoparticles (NPs) and their use as electrocatalysts are reported. Galvanic displacement with Ag NPs is used to obtain hollow NPs, and higher reduction potential of Au compared to Ag, Pd, and Pt helps to produce hollow Au cores first, followed by Pd or Pt shell growth. Continuous and highly crystalline shell growth was observed in Au@Pd core-shell NPs, but the sporadic and porous-like structure was observed in Au@Pt core-shell NPs. Along with hollow core-shell NPs, hollow porous Pt and hollow Au NPs are also prepared from Ag seed NPs. Twin boundaries which are typically observed in large size (>20 nm) Au NPs were not observed in hollow Au NPs. This absence is believed to be due to the role of the hollows, which significantly reduce the strain energy of edges where the two lattice planes meet. In ethanol oxidation reactions in alkaline medium, hollow Au@Pd core-shell NPs show highest current density in forward scan. Hollow Au@Pt core-shell NPs maintain better catalytic activities than metallic Pt, which is thought to be due to the better crystallinity of Pt shells as well as the alloy effect of Au cores. © 2012 The Royal Society of Chemistry.

  5. The Au-S bond in biomolecular adsorption and electrochemical electron transfer

    DEFF Research Database (Denmark)

    Ford, M. J.; Hush, N. S.; Marcuccio, S.

    is the electronic structure of the Au-S link and the packing of the SAMs. We have, first disentangled a wealth of data to identify the nature of the core Au-S contact. All data suggest that the electronic Au-S link is dominated by a Au(0)-thiyl radical with strong vander Waals forces and not by a Au...

  6. Correlation of magnetism and structure for ultra thin Au/Co/Au films: Evidence for magnetoelastic effects

    Energy Technology Data Exchange (ETDEWEB)

    Sakamaki, M; Konishi, T; Fujikawa, T [Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoicho, Inage, Chiba 263-8522 (Japan); Persson, A; Andersson, C; Karis, O; Arvanitis, D [Department of Physics and Material Science, Uppsala University, Box 530, SE-75121 Uppsala (Sweden); Rossner, H; Holub-Krappe, E, E-mail: holub-krappe@helmholtz-berlin.d [Helmholtz Centre Berlin for Materials and Energy, Lise Meitner Campus, Glienicker Str. 100, D-14109 Berlin (Germany)

    2009-11-15

    The spin-reorientation transition of thin Au/Co/Au films, grown in-situ on W(110), is studied in XMCD and EXAFS experiments. At 300 K, for in-situ grown Co on a Au(111) film, the dominant easy magnetization direction was found to be in the surface plane, for the uncapped Co/Au bilayers. This is a novel observation, in terms of easy magnetization direction for low thickness Co on Au. After capping with Au, a sizeable out-of-plane magnetization is observed below a thickness of four atomic Co layers. When the spin-reorientation transition occurs because of Au capping, a 5 A thin Co layer undergoes structural changes of lattice parameters {Delta}a/a = -1.2 % and {Delta}c/c = +6.6 %. The observation of structural changes which accompany the spin reorientation transition, contradicts previous work on Co/Au(111), and allows to quantify the magnetoelastic energy contribution, connected with the presence of the Co/Au interface.

  7. Role of ceramic matrix and Au fraction on the morphology and optical properties of cosputtered Au-ceramic thin films

    Science.gov (United States)

    Hazra, S.; Gibaud, A.; Sella, C.

    2007-06-01

    Surface sensitive x-ray scattering studies were carried out to understand the morphology of cermet thin films prepared by cosputtering metallic gold and ceramic materials on float glass substrates. It has been observed that the morphology of Au clusters in cermet thin films depends strongly on the matrix during growth, even if, all other conditions are kept identical. In particular, nearly isotropic growth of Au clusters, to form nanoparticles, is found in silica and alumina matrices, while anisotropic columnar-like growth of Au clusters, to form a nanorod-like shape, is found in a titanium oxide matrix. Thickness of the films was also found very different, which is likely to be related to the different sputtering yields of the ceramic materials. The volume fraction of Au estimated from the electron density profile shows that the total volume or the amount of Au is different in films of different ceramic matrices. This suggests that even the sputtering yield of Au is very different in the presence of different ceramic atmosphere, which is likely to be responsible for having a different morphology of Au clusters in different matrices. Optical absorption spectra of the films, on the other hand, show linear dependence of the absorption peak position with the volume fraction of Au and independent of both the ceramic matrix and morphology of Au clusters.

  8. Gold surfaces and nanoparticles are protected by Au(0)-thiyl species and are destroyed when Au(I)-thiolates form

    DEFF Research Database (Denmark)

    Reimers, Jeffrey R.; Ford, Michael J.; Halder, Arnab

    2016-01-01

    The synthetic chemistry and spectroscopy of sulfur-protected gold surfaces and nanoparticles is analyzed, indicating that the electronic structure of the interface is Au(0)-thiyl, with Au(I)-thiolates identified as high-energy excited surface states. Density-functional theory indicates...... that it is the noble character of gold and nanoparticle surfaces that destabilizes Au(I)-thiolates. Bonding results from large van der Waals forces, influenced by covalent bonding induced through s-d hybridization and charge polarization effects that perturbatively mix in some Au(I)-thiolate character. A simple method...

  9. Production et commercialisation durables de l'indigo au Salvador ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Asociación Balsamo tente de mettre au point un nouveau modèle agroindustriel de production d'indigo, au Salvador, qui permettra aux petits exploitants de faire de cette culture leur principale source de revenus. Le projet permettra à une équipe ...

  10. Fuzzy analytical hierarchy process and GIS for predictive cu -au ...

    African Journals Online (AJOL)

    In the Mokhtaran sheet for predictive Cu -Au porphyry this method was used. Combining this way with geographic information systems GIS is effective approach for predictive Mineral prospectively mapping (MPM) for Cu -Au porphyry. For preparing MPM, the criteria were geological data (host rocks, heat rocks, alteration), ...

  11. AuAg alloy nanomolecules with 38 metal atoms

    Science.gov (United States)

    Kumara, Chanaka; Dass, Amala

    2012-06-01

    Au38-nAgn(SCH2CH2Ph)24 alloy nanomolecules were synthesized, purified and characterized by MALDI TOF mass spectrometry. Similar to 25 and unlike 144 metal atom count AuAg alloy nanomolecules, incorporation of Ag atoms here results in loss or smearing out of distinct UV-vis features. We propose that the short and long staples contain Au atoms, while the inner core consists of both Au and Ag atoms.Au38-nAgn(SCH2CH2Ph)24 alloy nanomolecules were synthesized, purified and characterized by MALDI TOF mass spectrometry. Similar to 25 and unlike 144 metal atom count AuAg alloy nanomolecules, incorporation of Ag atoms here results in loss or smearing out of distinct UV-vis features. We propose that the short and long staples contain Au atoms, while the inner core consists of both Au and Ag atoms. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11781a

  12. Synthesis and stability of monolayer-protected Au38 clusters

    NARCIS (Netherlands)

    Toikkanen, O.; Ruiz, V.; Rönnholm, G.; Kalkkinen, N.; Liljeroth, P.W.|info:eu-repo/dai/nl/314007423; Quinn, B.M.

    2008-01-01

    A synthesis strategy to obtain monodisperse hexanethiolate-protected Au38 clusters based on their resistance to etching upon exposure to a hyperexcess of thiol is reported. The reduction time in the standard Brust−Schiffrin two-phase synthesis was optimized such that Au38 were the only clusters that

  13. Facile Growth of Multi-twined Au Nanostructures

    Indian Academy of Sciences (India)

    We describe a facile growth of chain-like Au nanostructures and their spontaneous transformation to multi-twined nanostructure using a mild reducing agent bisphenol A (BPA). The growth Au nanostructures involves the chemical reduction of HAuCl4 by BPA in the presence of cetyltrimethylammonium bromide (CTAB) as ...

  14. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon [Univ. of California, Berkeley, CA (United States)

    2002-05-01

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  15. Giant magnetoresistance of dissymmetrical Co/Au multilayers

    Science.gov (United States)

    Kolb, E.; Walker, M. J.; Vélu, E.; Howson, M. A.; Veillet, P.; Greig, D.; Renard, J. P.; Dupas, C.

    1996-04-01

    Results are presented for the magnetoresistance (MR) of sapphire/Nb 3/Cu 3/Au 8/(Co/Au 8) n dissymmetrical multilayers built by alternating a 0.3 nm discontinuous Co layer with a 0.7 nm continuous one. The observed enhanced MR is related to a higher spin scattering asymmetry for the granular Co layers.

  16. CO oxidation on Alsbnd Au nano-composite systems

    Science.gov (United States)

    Rajesh, C.; Majumder, C.

    2018-03-01

    Using first principles method we report the CO oxidation behaviour of Alsbnd Au nano-composites in three different size ranges: Al6Au8, Al13Au42 and a periodic slab of Alsbnd Au(1 1 1) surface. The clusters prefer enclosed structures with alternating arrangement of Al and Au atoms, maximising Auδ-sbnd Alδ+ bonds. Charge distribution analysis suggests the charge transfer from Al to Au atoms, corroborated by the red shift in the density of states spectrum. Further, CO oxidation on these nano-composite systems was investigated through both Eley - Rideal and Langmuir Hinshelwood mechanism. While, these clusters interact with O2 non-dissociatively with an elongation of the Osbnd O bond, further interaction with CO led to formation of CO2 spontaneously. On contrary, the CO2 evolution by co-adsorption of O2 and CO molecules has a transition state barrier. On the basis of the results it is inferred that nano-composite material of Alsbnd Au shows significant promise toward effective oxidative catalysis.

  17. Growth and structure of Co/Au magnetic thin films; Croissance et structure des couches minces magnetiques Co/Au

    Energy Technology Data Exchange (ETDEWEB)

    Marsot, N

    1999-01-14

    We have studied the growth and the crystallographic structure of magnetic ultra thin cobalt/gold films (Co/Au), in order to investigate the correlations between their magnetic and structural properties. Room temperature (R.T.) Co growth on Au (111) proceeds in three stages. Up to 2 Co monolayers (ML), a bilayer island growth mode is observed. Between 2 and 5 ML, coalescence of the islands occurs, covering the substrate surface and a Co/Au mixing is observed resulting from the de-construction of the Herringbone reconstruction. Finally, beyond 5 ML, the CoAu mixing is buried and the Co growth continues in a 3-D growth. Annealing studies at 600 K on this system show a smoothing effect of the Co film, and at the same time, segregation of Au atoms. The quality of the Co/Au interface (sharpness) is not enhanced by the annealing. The local order was studied by SEXAFS and the long range order by GIXRD showing that the Co film has a hexagonal close packed structure, with an easy magnetization axis perpendicular to the surface. From a local order point of view, the Co grows with an incoherent epitaxy and keeps its own bulk parameters. The GIXRD analysis shows a residual strain in the Co film of 4%. The difference observed between the local order analysis and the long range order results is explained in terms of the low dimensions of the diffracting domains. The evolution of film strains, as a function of the Co coverage, shows a marked deviation from the elastic strain theory. Modification of the strain field in the Co film as a function of the Au coverage is studied by GIXRD analysis. The Au growth study, at R.T., shows no evidence of a Au/Co mixing in the case of the Au/Co interface. The Au overlayer adopts a twinned face centred cubic structure on the rough Co film surface. (author)

  18. Au@PdOx with a PdOx-rich shell and Au-rich core embedded in Co3O4 nanorods for catalytic combustion of methane.

    Science.gov (United States)

    Yang, Nating; Liu, Jingwei; Sun, Yuhan; Zhu, Yan

    2017-02-09

    Au@PdOx with a PdOx-rich shell and Au-rich core nested in Co3O4 nanorods exhibited enhanced catalytic performance in the reaction of methane catalytic combustion, compared to monometallic Pd or Au/Co3O4 nanorods as well as conventional PdAu/Co3O4 nanorods. The superior catalysis of Au@PdOx/Co3O4 nanorods is mainly due to the architectural style of the PdOx-rich shell and Au-rich core, which shows strong interaction of Pd, Au, and Co3O4.

  19. Panorama du roman policier au Mexique

    OpenAIRE

    Lara-Alengrin, Alba

    2013-01-01

    Malgré sa diffusion depuis les années quarante par des collections de poche autochtones, le roman policier fut longtemps, au Mexique, un genre méprisé par la critique et les écrivains. Paco Ignacio Taibo II est le premier écrivain mexicain a légitimer et valoriser le genre policier, en particulier le roman noir, qui connaît simultanément un regain d’intérêt critique et commercial. Ce changement de perception vis-à-vis du roman noir s’accompagne de la création d’un nouveau terme pour le qualif...

  20. Interface stress in Au/Ni multilayers

    DEFF Research Database (Denmark)

    Schweitz, K.O.; Böttiger, J.; Chevallier, J.

    2000-01-01

    The effect of intermixing on the apparent interface stress is studied in -textured dc-magnetron sputtered Au/Ni multilayers by use of two methods commonly used for determining interface stress. The method using profilometry and in-plane x-ray diffraction does not take intermixing...... into account and yields an apparent interface stress of -8.46 +/- 0.99 J m(-2). However, observed discrepancies between model calculations and measured high-angle x-ray diffractograms indicate intermixing, and by use of the profilometry and sin(2) psi method the real interface stress value of -2.69 +/- 0.43 J...... m(-2) is found. This method also reveals a significant and systematic change of the stress-free lattice parameter of both constituents as a function of modulation period which is shown to account for the difference between the two findings. The method using in-plane diffraction is thus shown...

  1. La Physique au LHC - Partie I

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    Le LHC devrait permettre l'observation du boson de Higgs et pouvoir lever le voile sur l'un des scénarios de nouvelle physique présentés dans la cours précédent. Ce cours détaillera les perspectives de physique au LHC (découvertes possibles et mesures de précision) ainsi que les méthodes et difficultés expérimentales. L'accent sera mis sur les problèmes liés à la brisure de la symétrie electrofaible. Les possibilités de développement futur à plus haute luminosité et/ou énergie seront également discutées.

  2. and Au nanoparticles for SERS applications

    Directory of Open Access Journals (Sweden)

    Fazio Enza

    2018-01-01

    Full Text Available The morphological and optical properties of noble metal nanoparticles prepared by picosecond laser generated plasmas in water were investigated. First, the ablation efficiency was maximized searching the optimal focusing conditions. The nanoparticle size, measured by Scanning Transmission Electron Microscopy, strongly depends on the laser fluence, keeping fixed the other deposition parameters such as the target to scanner objective distance and laser repetition frequency. STEM images indicate narrow gradients of NP sizes. Hence the optimization of ablation parameters favours a fine tuning of nanoparticles. UV-Visible spectroscopy helped to determine the appropriate laser wavelength to resonantly excite the localized surface plasmon to carry out Surface Enhanced Raman Scattering (SERS measurements. The SERS activity of Ag and Au substrates, obtained spraying the colloids synthesized in water, was tested using crystal violet as a probe molecule. The good SERS performance, observed at excitation wavelength 785 nm, is attributed to aggregation phenomena of nanoparticles sprayed on the support.

  3. Une barque au bout du lac

    OpenAIRE

    El-Kharrat, Edouard

    2008-01-01

    Quand la terre resplendit sous le soleil et que vint le jour, je m'en fus vers l'étang. C'est là que je la vis, l'inhumaine. Ma chair frémit quand je la regardai. Sa peau était fraîche et douce. Et depuis son amour vit toujours en mon corps. L'éblouissement qui s'écoulait pourtant par la voûte du monde avait un instant pâli derrière une blanche nuée. Et l'auberge, grêlée, murs de pierre grise, larges portes au treillis vermoulu mouchetées de trous creusé par le soleil et le vent salé, se dres...

  4. Unique Properties of Core Shell Ag@Au Nanoparticles for the Aptasensing of Bacterial Cells

    National Research Council Canada - National Science Library

    Hamidi-Asl, Ezat; Dardenne, Freddy; Pilehvar, Sanaz; Blust, Ronny; De Wael, Karolien

    2016-01-01

    ...) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silver–gold core shell (Ag@Au), gold–silver core shell (Au@Ag), and silver...

  5. Spin-polarized ballistic conduction through correlated Au-NiMnSb-Au heterostructures

    Science.gov (United States)

    Morari, C.; Appelt, W. H.; Östlin, A.; Prinz-Zwick, A.; Schwingenschlögl, U.; Eckern, U.; Chioncel, L.

    2017-11-01

    We examine the ballistic conduction through Au-NiMnSb-Au heterostructures consisting of up to four units of the half-metallic NiMnSb in the scattering region, using density functional theory (DFT) methods. For a single NiMnSb unit the transmission function displays a spin polarization of around 50 % in a window of 1 eV centered around the Fermi level. By increasing the number of layers, an almost complete spin polarization of the transmission is obtained in this energy range. Supplementing the DFT calculations with local electronic interactions, of Hubbard-type on the Mn sites, leads to a hybridization between the interface and many-body states. The significant reduction of the spin polarization seen in the density of states is not apparent in the spin polarization of the conduction electron transmission, which suggests that the hybridized interface and many-body induced states are localized.

  6. Spin-polarized ballistic conduction through correlated Au-NiMnSb-Au heterostructures

    KAUST Repository

    Morari, C.

    2017-11-20

    We examine the ballistic conduction through Au-NiMnSb-Au heterostructures consisting of up to four units of the half-metallic NiMnSb in the scattering region, using density functional theory (DFT) methods. For a single NiMnSb unit the transmission function displays a spin polarization of around 50% in a window of 1eV centered around the Fermi level. By increasing the number of layers, an almost complete spin polarization of the transmission is obtained in this energy range. Supplementing the DFT calculations with local electronic interactions, of Hubbard-type on the Mn sites, leads to a hybridization between the interface and many-body states. The significant reduction of the spin polarization seen in the density of states is not apparent in the spin polarization of the conduction electron transmission, which suggests that the hybridized interface and many-body induced states are localized.

  7. Un nouvel oxyde naturel de Au et Sb

    Science.gov (United States)

    Johan, Zdenek; Šrein, Vladimir

    1998-04-01

    A gold-antimony X-ray amorphous oxide, resulting from a hydrothermal alteration of aurostibite, AuSb 2, occurs in the Krásná Hora gold deposit, Czech Republic. Its reflectivity is close to that of goethite. The average composition obtained by electron microprobe analyses (wt. %) is: Au - 68.32; Cu - 0.10; Sb - 21.26; As - 0.30; Si - 0.21; O - 8.44; total 98.63. This yields the empirical formula (Au 0.677Cu 0.003Sb 0.341As 0.008) 1.029O. The[(Au + Cu)/(Sb + As)] at ratio varies from 1.86 to 1.95. Among possible formulae satisfying the equilibrium of charges, that implying unique valence states for Au and/or Sb was retained. It can be written Au 1+2Sb 3+O 2(OH) with the theoretical composition (wt, %): Au - 69.76; Sb - 21.54; O - 8.50; H - 0.20. This Au- and Sb-bearing oxide is associated with native gold, electrum, aurostibite, arsenopyrite and pyrite in a quartz gangue. The powder pattern of AuSbO 3 was indexedon an orthorhombic unit-cell with a = 5.00(2); b = 12.46(4); c = 5.43(2) Å, Z = 4, Q calc = 7.20 g.cm 3, assuming a replacement of Sb 3+ by Au 3+ in the valentinite-type crystal structure.

  8. Devenir De l'azote de L'engrais enrichi au n applique au tournesol ...

    African Journals Online (AJOL)

    L'utilisation de I' azote de I' engrais par la culture de toumesol a ete appreciee par Ia determination du coefficient d'utilisation apparent (CUA) estime par Ia methode de difference et du coefficient d'utilisation reel (CUR) estime par Ia methode isotopique. 80 kg N ha-1 a 4.87% d'atomes en exces de 15N ont ete appliques au ...

  9. Mise au point d'un test in vitro de comportement au sel de quatre ...

    African Journals Online (AJOL)

    agrumes, en termes de résistance à la salinité in vitro au niveau des cals et des cellules cultivées parallèlement sur milieu liquide et solide. Méthodologie et résultat : À cet égard, des cals de quatre génotypes d'agrumes : mandarinier Cléopâtre ...

  10. Seropositivite au vih et grossesse au Togo: vecu et representation a ...

    African Journals Online (AJOL)

    Introduction : Ce travail avait pour objectifs d'identifier les indicateurs de la représentation et du vécu des femmes enceintes séropositives d'une part, et de rechercher un lien entre ces indicateurs chez ces femmes au sud du Togo. Méthodologie : Le cadre de notre étude ont été l'hôpital de Bè, le centre de santé de Lomé, ...

  11. Les Modalites Evolutives Du Zona Au Cours De L\\'infection A Vih Au ...

    African Journals Online (AJOL)

    Introduction et But Peu d\\'informations sont disponibles sur les complications du zona et la prise en charge globale de cette maladie chez les patients VIH-positifs dans les pays d\\'Afrique sub Saharienne à l\\'instar du Cameroun. Le taux de séroprévalence du VIH dans la population adulte générale au Cameroun à été ...

  12. Characterization of Au3+ species in Au/C catalysts for the hydrochlorination reaction of acetylene

    OpenAIRE

    Conte, M.; Davies, C.J.; Morgan, D.J.; Carley, A.F.; Johnston, P.; Hutchings, G.J.

    2014-01-01

    A set of Au/C catalysts for the gas phase hydrochlorination of acetylene to vinyl chloride monomer were prepared using a range of strong acids as impregnating solvents and varying the preparation drying temperature. The most active catalyst is the material prepared using aqua regia as solvent with an intermediate drying temperature of 140 °C. The effects of the catalyst preparation parameters on the catalytic activity are examined using XPS and TPR as analytical tools. In particular, the use ...

  13. Au Kenya, des oiseaux nuisent à une culture adaptée au climat ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    23 août 2013 ... KITUI, Kenya (Thomson Reuters Foundation) – Le gadam, une variété de sorgho à croissance rapide résistante à la sécheresse, a été introduit au Kenya comme solution d'adaptation aux changements climatiques. Or, il se trouve que le gadam comporte un inconvénient imprévu : les oiseaux sauvages ...

  14. Emploi et revenu en Bolivie, au Paraguay et au Pérou : analyse des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Comme beaucoup d'autres pays d'Amérique latine, la Bolivie, le Paraguay et le Pérou ont entrepris des réformes structurelles au cours des années 1980 et 1990 dans le but d'atteindre la stabilité macroéconomique et de susciter la croissance économique. On s'attendait à ce que la croissance s'accompagne d'emplois ...

  15. Amélioration de la nutrition au Cambodge au moyen de l ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le régime alimentaire des ménages en milieu rural au Cambodge est habituellement pauvre en protéines et en micronutriments, et il en résulte des taux élevés de retard de croissance chez les enfants et d'anémie chez les femmes. Studies. Biochemical correlates of anemia in Cambodian women of reproductive age ...

  16. Biosynthesis of Au, Ag and Au-Ag nanoparticles using edible mushroom extract

    Science.gov (United States)

    Philip, Daizy

    2009-07-01

    Integration of green chemistry principles to nanotechnology is one of the key issues in nanoscience research. There is growing need to develop environmentally benign metal nanoparticle synthesis process that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on extracellular synthesis method for the preparation of Au, Ag and Au-Ag nanoparticles in water, using the extract of Volvariella volvacea, a naturally occurring edible mushroom, as reducing and protecting agents. Gold nanoparticles of different sizes (20-150 nm) and shapes from triangular nanoprisms to nearly spherical and hexagonal are obtained by this novel method. The size and shape of gold nanoparticles are also found to depend on temperature of the extract. The silver nanoparticles are spherical with size ˜15 nm. There is increased productivity of nanoparticles as shown by sharp and intense surface plasmon resonance bands for the nanoparticles prepared using an excess of the extract. The Au-Ag nanoparticles prepared by co-reduction has only one plasmon band due to alloying of the constituents. All the synthesized nanoparticles are found to be photoluminescent and are highly crystalline as shown by SAED and XRD patterns with fcc phase oriented along the (1 1 1) plane. FTIR measurements were carried out to identify the possible biomolecules responsible for capping and efficient stabilization of the nanoparticles. It is found that Au nanoparticles are bound to proteins through free amino groups and silver nanoparticles through the carboxylate group of the amino acid residues. The position and intensity of the emission band is found to depend on composition of the nanoparticles indicating the possible use in therapeutic applications.

  17. Prévention de la violence chez les jeunes au Guatemala, au ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Même si les gouvernements associent la plupart de ces infractions au crime organisé, aux gangs de rue et aux criminels de droit commun, ils ne disposent que de peu de preuves pour étayer leurs conclusions, étant donné que leurs capacités de recherche sont extrêmement faibles. D'ailleurs, le taux de crimes impunis (ne ...

  18. Exécution de penalties et de tirs au but au football : maîtrise ...

    African Journals Online (AJOL)

    Exécution de penalties et de tirs au but au football : maîtrise technique ou gestion des émotions chez les tireurs et les gardiens de but. KP Edoh, F Messan, F Dosseville, L Tanimomo, CH Gnidete ...

  19. Neutron diffraction study of La 4LiAuO 8: Understanding Au 3+ in an oxide environment

    Science.gov (United States)

    Kurzman, Joshua A.; Moffitt, Stephanie L.; Llobet, Anna; Seshadri, Ram

    2011-06-01

    Owing to gold's oxophobicity, its oxide chemistry is rather limited, and elevated oxygen pressures are usually required to prepare ternary and quaternary oxide compounds with gold ions. The Au 3+ oxide, La 4LiAuO 8, is remarkable both because it can be prepared at ambient pressure in air, and because of its unusual stability toward thermal decomposition and reduction. The structure of La 4LiAuO 8 was established by Pietzuch et al. using single crystal X-ray diffraction [1]. The compound adopts an ordered modification of the Nd 2CuO 4 structure, containing two-dimensional sheets in which AuO 4 square planes are separated from one another by LiO 4 square planes. In light of the meager X-ray scattering factors of Li and O, relative to La and Au, we report here a neutron powder diffraction study of La 4LiAuO 8, definitively confirming the structure. To our knowledge, this is the first reported neutron diffraction study of any stoichiometric oxide compound of gold. X- N maps, which make use of nuclear positions obtained from Rietveld refinement of time-of-flight neutron diffraction data and electron densities obtained from synchrotron X-ray powder diffraction data, point to the highly covalent nature of the Au-O bonding in La 4LiAuO 8. This is in good agreement with charge densities and Bader charges obtained from full density functional relaxation of the structure.

  20. Promotion of Phenol Photodecomposition over TiO2 Using Au, Pd, and AuPd Nanoparticles

    DEFF Research Database (Denmark)

    Su, Ren; Tiruvalam, Ramchandra; He, Qian

    2012-01-01

    Noble metal nanoparticles (Au, Pd, AuPd alloys) with a narrow size distribution supported on nanocrystalline TiO2 (M/TiO2) have been synthesized via a sol-immobilization route. The effect of metal identity and size on the photocatalytic performance of M/TiO2 has been systematically investigated u...

  1. Effect of Au nano-particle aggregation on the deactivation of the AuCl3/AC catalyst for acetylene hydrochlorination

    OpenAIRE

    Dai, Bin; Wang, Qinqin; Yu, Feng; Zhu, Mingyuan

    2015-01-01

    A detailed study of the valence state and distribution of the AuCl3/AC catalyst during the acetylene hydrochlorination deactivation process is described and discussed. Temperature-programmed reduction and X-ray photoelectron spectral analysis indicate that the active Au3+ reduction to metallic Au0 is one reason for the deactivation of AuCl3/AC catalyst. Transmission electron microscopy characterization demonstrated that the particle size of Au nano-particles increases with increasing reaction...

  2. Au@AuPt nanoparticles embedded in B-doped graphene: A superior electrocatalyst for determination of rutin

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xianlan; Yang, Guangming; Feng, Shaoping; Shi, Ling; Huang, Zhaolong [School of Science, Honghe University (China); Key Laboratory of Natural Pharamaceutical & Chemical Biology of Yunnan Province Mengzi, Yunnan 661100 (China); Pan, Haibo [Fujian Key Lab of Medical Instrument & Pharmaceutical Technology, Yishan Campus, Fuzhou University, Fuzhou, Fujian 350002 (China); Liu, Wei, E-mail: liuwei4728@126.com [School of Science, Honghe University (China); Key Laboratory of Natural Pharamaceutical & Chemical Biology of Yunnan Province Mengzi, Yunnan 661100 (China)

    2017-04-30

    Highlights: • The formation of B-doped graphene (BG) with high content of a total B species use hydrothermal method with B{sub 2}O{sub 3} as reducing agent and boron source. • BG was exfoliated into monolayer nanosheet impregnated by Au@AuPt NPs because B atom creates a net positive charge to facilitate NPs adsorption. • The dispersed carboxyl units of BG can form hydrogen bonding with the phenolic hydroxyl groups of rutin, making more rutin participate in reaction. • Au@AuPt NPs can form charge accumulation or valence change on prominent part of the surface, improving the catalytic effect to rutin. • More electroactive sites were generated by doping B atoms into graphene structures, which act as multidimensional electron transport pathways. - Abstract: A hydrothermal approach was used to prepare B-doped graphene with B{sub 2}O{sub 3} as reductant and boron source. Results reveal that the boron atoms have been successfully embedded into graphene with a high content of a total B species (2.85 at.%). Then, B-doped graphene was exfoliated further into monolayer nanosheet by impregnating Au@AuPt core-shell nanoparticles (Au@AuPt NPs) because boron atom creates a net positive charge, which facilitates Au@AuPt NPs adsorption to form Au@AuPt NPs/B-doped graphene hybrid nanocatalysts. After that, the Au@AuPt NPs/B-doped hybrid suspension was dropped on glassy carbon electrode for sensing rutin. In this way, the dispersed carboxyl units of B-doped graphene can form hydrogen bonding with the phenolic hydroxyl groups of rutin, making rutin enrich easily on modified electrode surface to enhance the electrochemical response. At the same time, its electrochemical mechanism on the modified electrode was elucidated using cyclic voltammetry. It was found that its electrochemical behavior on modified electrode surface was a surface-controlled quasi-reversible process, and the charge transfer coefficient (α) and electron transfer number (n) were 0.296 and 2, respectively

  3. Structure and Mobility of Metal Clusters in MOFs: Au, Pd, and AuPd Clusters in MOF-74

    DEFF Research Database (Denmark)

    Vilhelmsen, Lasse; Walton, Krista S.; Sholl, David S.

    2012-01-01

    Understanding the adsorption and mobility of metal–organic framework (MOF)-supported metal nanoclusters is critical to the development of these catalytic materials. We present the first theoretical investigation of Au-, Pd-, and AuPd-supported clusters in a MOF, namely MOF-74. We combine density...... functional theory (DFT) calculations with a genetic algorithm (GA) to reliably predict the structure of the adsorbed clusters. This approach allows comparison of hundreds of adsorbed configurations for each cluster. From the investigation of Au8, Pd8, and Au4Pd4 we find that the organic part of the MOF......’s adsorption energy and diffusion barrier is established, confirming that Au clusters are highly mobile in the MOF-74 framework and Pd clusters are less mobile....

  4. High-temperature stability of Au/Pd/Cu and Au/Pd(P)/Cu surface finishes

    Science.gov (United States)

    Ho, C. E.; Hsieh, W. Z.; Lee, P. T.; Huang, Y. H.; Kuo, T. T.

    2018-03-01

    Thermal reliability of Au/Pd/Cu and Au/Pd(4-6 wt.% P)/Cu trilayers in the isothermal annealing at 180 °C were investigated by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and transmission electron microscopy (TEM). The pure Pd film possessed a nanocrystalline structure with numerous grain boundaries, thereby facilitating the interdiffusion between Au and Cu. Out-diffusion of Cu through Pd and Au grain boundaries yielded a significant amount of Cu oxides (CuO and Cu2O) over the Au surface and gave rise to void formation in the Cu film. By contrast, the Pd(P) film was amorphous and served as a good diffusion barrier against Cu diffusion. The results of this study indicated that amorphous Pd(P) possessed better oxidation resistance and thermal reliability than crystalline Pd.

  5. Production des baryons multi-étranges au LHC dans les collisions proton-proton avec l'expérience ALICE

    CERN Document Server

    Maire, Antonin

         Strange quarks define a valuable probe for the understanding of quantum chromodynamics. The present PhD work falls within this scope; it deals with the study of multi-strange baryons Ξ– (dss) and Ω– (sss) in proton-proton (pp) collisions at the LHC. The analyses make use of the ALICE experiment and are performed at central rapidities (y ≈ 0) and low transverse momentum (pT < 8,5 GeV/c). The production rates per event of these baryons are drawn from the measurement of differential spectra as a function of the hyperon momentum, d²N / dpTdy = f(pT). At √s = 0.9 TeV, the production for ( Ξ– + Ξ+ ) in the inelastic pp interactions is derived from a small statistics of events. At √s = 7 TeV, the large quantity of available data allows the measurement of production rates for each of the four species : Ξ–, Ξ+, Ω– and Ω+. At both energies, experimental data spectra are compared to spectra as produced by different benchmark phenomenological models (Pythia...

  6. Au@AuPt nanoparticles embedded in B-doped graphene: A superior electrocatalyst for determination of rutin

    Science.gov (United States)

    Chen, Xianlan; Yang, Guangming; Feng, Shaoping; Shi, Ling; Huang, Zhaolong; Pan, Haibo; Liu, Wei

    2017-04-01

    A hydrothermal approach was used to prepare B-doped graphene with B2O3 as reductant and boron source. Results reveal that the boron atoms have been successfully embedded into graphene with a high content of a total B species (2.85 at.%). Then, B-doped graphene was exfoliated further into monolayer nanosheet by impregnating Au@AuPt core-shell nanoparticles (Au@AuPt NPs) because boron atom creates a net positive charge, which facilitates Au@AuPt NPs adsorption to form Au@AuPt NPs/B-doped graphene hybrid nanocatalysts. After that, the Au@AuPt NPs/B-doped hybrid suspension was dropped on glassy carbon electrode for sensing rutin. In this way, the dispersed carboxyl units of B-doped graphene can form hydrogen bonding with the phenolic hydroxyl groups of rutin, making rutin enrich easily on modified electrode surface to enhance the electrochemical response. At the same time, its electrochemical mechanism on the modified electrode was elucidated using cyclic voltammetry. It was found that its electrochemical behavior on modified electrode surface was a surface-controlled quasi-reversible process, and the charge transfer coefficient (α) and electron transfer number (n) were 0.296 and 2, respectively. This electrochemical sensor for rutin provided a wide linear response range of 2.00 × 10-9-4.00 × 10-6 M with the detection limit (S/N = 3) of 2.84 × 10-10 M. The proposed method was applied successfully to selective determination of rutin in Tablets with acceptable recovery range (97.23-101.65%).

  7. Deep level anomalies in silicon doped with radioactive Au atoms

    CERN Document Server

    Bollmann, J; Henry, M O; McGlynn, E; Knack, S

    1999-01-01

    DLTS investigations on n- and p-type silicon samples implanted with various radioactive Hg isotopes which decay fully or partly through the series Au/Pt/(Ir) are reported. The deep Au-donor level at E/sub v/+0.374(3) eV is observed in all cases. In p-type silicon its energy differs significantly (E/sub v/+0.438(3) eV). Both Au and Pt are found to produce two acceptor levels in n-type material. An additional donor-like level at E/sub v/+0.499(4) eV is shown to be due to Au. In all detected levels, one atom of Au or Pt is involved and the concentration decreases towards crystal surface. A key result is that, despite the presence of the Au donor in the samples, for all decay series involving Au to Pt conversion we have never observed the appearance of the Pt-donor. (6 refs).

  8. SORPTION OF Au(III BY Saccharomyces cerevisiae BIOMASS

    Directory of Open Access Journals (Sweden)

    Amaria Amaria

    2010-07-01

    Full Text Available Au(III sorption by S. cerevisiae biomass extracted from beer waste industry was investigated. Experimentally, the sorption was conducted in batch method. This research involved five steps: 1 identification the functional groups present in the S. cerevisiae biomass by infrared spectroscopic technique, 2 determination of optimum pH, 3 determination of the sorption capacity and energy, 4 determination of the sorption type by conducting desorption of sorbed Au(III using specific eluents having different desorption capacity such as H2O (van der Waals, KNO3 (ion exchange, HNO3 (hydrogen bond, and tiourea (coordination bond, 5 determination of effective eluents in Au(III desorption by partial desorption of sorbed Au(III using thiourea, NaCN and KI. The remaining Au(III concentrations in filtrate were analyzed using Atomic Absorption Spectrophotometer. The results showed that: 1 Functional groups of S. cerevisiae biomass that involved in the sorption processes were hydroxyl (-OH, carboxylate (-COO- and amine (-NH2, 2 maximum sorption was occurred at pH 4, equal to 98.19% of total sorption, 3 The sorption capacity of biomass was 133.33 mg/g (6.7682E-04 mol/g and was involved sorption energy 23.03 kJ mol-1, 4 Sorption type was dominated by coordination bond, 5 NaCN was effective eluent to strip Au(III close to 100%.   Keywords: sorption, desorption, S. cerevisiae biomass, Au(III

  9. Structural, electronic and magnetic properties of Au-based monolayer derivatives in honeycomb structure

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, Pooja, E-mail: pupooja16@gmail.com; Sharma, Munish; Ahluwalia, P. K. [Physics Department, Himachal Pradesh University, Shimla, Himachal Pradesh, India 171005 (India); Kumar, Ashok [Centre for Physical Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda, India, 151001 (India)

    2016-05-23

    We present electronic properties of atomic layer of Au, Au{sub 2}-N, Au{sub 2}-O and Au{sub 2}-F in graphene-like structure within the framework of density functional theory (DFT). The lattice constant of derived monolayers are found to be higher than the pristine Au monolayer. Au monolayer is metallic in nature with quantum ballistic conductance calculated as 4G{sub 0}. Similarly, Au{sub 2}-N and Au{sub 2}-F monolayers show 4G{sub 0} and 2G{sub 0} quantum conductance respectively while semiconducting nature with calculated band gap of 0.28 eV has been observed for Au{sub 2}-O monolayer. Most interestingly, half metalicity has been predicted for Au{sub 2}-N and Au{sub 2}-F monolayers. Our findings may have importance for the application of these monolayers in nanoelectronic and spintronics.

  10. Extreme interplanetary rotational discontinuities at 1 AU

    Science.gov (United States)

    Lepping, R. P.; Wu, C.-C.

    2005-11-01

    This study is concerned with the identification and description of a special subset of four Wind interplanetary rotational discontinuities (from an earlier study of 134 directional discontinuities by Lepping et al. (2003)) with some "extreme" characteristics, in the sense that every case has (1) an almost planar current sheet surface, (2) a very large discontinuity angle (ω), (3) at least moderately strong normal field components (>0.8 nT), and (4) the overall set has a very broad range of transition layer thicknesses, with one being as thick as 50 RE and another at the other extreme being 1.6 RE, most being much thicker than are usually studied. Each example has a well-determined surface normal (n) according to minimum variance analysis and corroborated via time delay checking of the discontinuity with observations at IMP 8 by employing the local surface planarity. From the variance analyses, most of these cases had unusually large ratios of intermediate-to-minimum eigenvalues (λI/λmin), being on average 32 for three cases (with a fourth being much larger), indicating compact current sheet transition zones, another (the fifth) extreme property. For many years there has been a controversy as to the relative distribution of rotational (RDs) to tangential discontinuities (TDs) in the solar wind at 1 AU (and elsewhere, such as between the Sun and Earth), even to the point where some authors have suggested that RDs with large ∣Bn∣s are probably not generated or, if generated, are unstable and therefore very rare. Some of this disagreement apparently has been due to the different selection criteria used, e.g., some allowed eigenvalue ratios (λI/λmin) to be almost an order of magnitude lower than 32 in estimating n, usually introducing unacceptable error in n and therefore also in ∣Bn∣. However, we suggest that RDs may not be so rare at 1 AU, but good quality cases (where ∣Bn∣ confidently exceeds the error in ∣Bn∣) appear to be uncommon, and further

  11. Insuffisance renale et infection au vih : Aspects epidemiologique ...

    African Journals Online (AJOL)

    But : Déterminer le profil épidémiologique, clinique et évolutif des personnes séropositives au VIH (PVVIH) présentant une insuffisance rénale (IR) hospitalisées en réanimation médicale au CHU Tokoin de Lomé. Méthodologie : Il s'est agit d'une étude rétrospective concernant les patients séropositives au VIH présentant ...

  12. Radiation effects on dielectric losses of Au-doped silicon

    Energy Technology Data Exchange (ETDEWEB)

    Molla, J.; Vila, R.; Ibarra, A. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain). Inst. de Investigacion Basica; Heidinger, R. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Materialforschung

    1998-10-01

    Effects of electron and neutron irradiation on dielectric properties of Au-doped silicon are examined as a function of the frequency between 1 kHz and 150 GHz. The studies compare the Au-doped Si with a high resistivity (HR) pure Si in the as-received state and after electron irradiation. The obtained data for both materials show that electron irradiation and neutron irradiation do not cause degradation of the dielectric loss behaviour, but even improve it. This beneficial effect already observed earlier in pure silicon is also observed in Au-doped silicon. Loss data obtained in-beam under electron irradiation are also reported. (orig.) 15 refs.

  13. Au(111) and Pt(111) surface phase behavior

    DEFF Research Database (Denmark)

    Sandy, A.R.; Mochrie, S.G.J.; Zehner, D.M.

    1993-01-01

    We describe our recent X-ray scattering studies of the structure and phases of the clean Au(111) and Pt(111) surfaces. Below 0.65 of their respective bulk melting temperatures, the Au(111) surface has a well-ordered chevron reconstruction and the Pt(111) surface is unreconstructed. Above...... these temperatures, both surfaces reconstruct to form layers that are isotropically compresses and have only short-range order. Throughout their reconstructed phases, the densities of the Au and Pt(111) surfaces increase with increasing temperature....

  14. Au plasmonics in a WS{sub 2}-Au-CuInS{sub 2} photocatalyst for significantly enhanced hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Zhongzhou [CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn; Shifa, Tofik Ahmed; Wang, Fengmei; Zhan, Xueying; Xu, Kai; He, Jun, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn [CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); Liu, Quanlin [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-11-30

    Promoting the activities of photocatalysts is still the critical challenge in H{sub 2} generation area. Here, a Au plasmon enhanced photocatalyst of WS{sub 2}-Au-CuInS{sub 2} is developed by inserting Au nanoparticles between WS{sub 2} nanotubes and CuInS{sub 2} (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS{sub 2}-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS{sub 2}-CIS, CIS-Au, WS{sub 2}-Au, and WS{sub 2}-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimize the type-II structures for photocatalytic water splitting.

  15. Chemical and electrical characteristics of annealed Ni/Au and Ni/Ir/Au contacts on AlGaN

    Energy Technology Data Exchange (ETDEWEB)

    Ngoepe, P.N.M., E-mail: phuti.ngoepe@up.ac.za [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa); Meyer, W.E.; Auret, F.D.; Omotoso, E.; Diale, M. [Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028 (South Africa); Swart, H.C.; Duvenhage, M.M.; Coetsee, E. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300 (South Africa)

    2016-01-01

    The evolution of Ni/Au and Ni/Ir/Au metal contacts deposited on AlGaN was investigated at different annealing temperatures. The samples were studied with electrical and chemical composition techniques. I–V characteristics of the Schottky diodes were optimum after 500 and 600 °C annealing for Ni/Au and Ni/Ir/Au based diodes, respectively. The depth profiles of the contacts were measured by x-ray photoelectron spectroscopy and time of flight secondary ion mass spectroscopy. These chemical composition techniques were used to examine the evolution of the metal contacts in order to verify the influence the metals have on the electrical properties of the diodes. The insertion of Ir as a diffusion barrier between Ni and Au effected the electrical properties, improving the stability of the contacts at high temperatures. Gold diffused into the AlGaN film, degrading the electrical properties of the Ni/Au diode. At 500 °C, the insertion of Ir, however, prevented the in-diffusion of Au into the AlGaN substrate.

  16. Evaluation of the Olympus AU-510 analyser.

    Science.gov (United States)

    Farré, C; Velasco, J; Ramón, F

    1991-01-01

    The selective multitest Olympus AU-510 analyser was evaluated according to the recommendations of the Comision de Instrumentacion de la Sociedad Española de Quimica Clinica and the European Committee for Clinical Laboratory Standards. The evaluation was carried out in two stages: an examination of the analytical units and then an evaluation in routine work conditions. The operational characteristics of the system were also studied.THE FIRST STAGE INCLUDED A PHOTOMETRIC STUDY: dependent on the absorbance, the inaccuracy varies between +0.5% to -0.6% at 405 nm and from -5.6% to 10.6% at 340 nm; the imprecision ranges between -0.22% and 0.56% at 405 nm and between 0.09% and 2.74% at 340 nm. Linearity was acceptable, apart from a very low absorbance for NADH at 340 nm; and the imprecision of the serum sample pipetter was satisfactory.TWELVE SERUM ANALYTES WERE STUDIED UNDER ROUTINE CONDITIONS: glucose, urea urate, cholesterol, triglycerides, total bilirubin, creatinine, phosphate, iron, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transferase.The within-run imprecision (CV%) ranged from 0.67% for phosphate to 2.89% for iron and the between-run imprecision from 0.97% for total bilirubin to 7.06% for iron. There was no carryover in a study of the serum sample pipetter. Carry-over studies with the reagent and sample pipetters shows some cross contamination in the iron assay.

  17. Time interval measurement between two emissions: Kr + Au; Mesure de l`intervalle de temps entre deux emissions: Kr + Au

    Energy Technology Data Exchange (ETDEWEB)

    Aboufirassi, M; Bougault, R.; Brou, R.; Colin, J.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Mahi, M.; Steckmeyer, J.C.; Tamain, B. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France); LPC (Caen) - CRN (Strasbourg) - GANIL Collaboration

    1998-04-01

    To indicate the method allowing the determination of the emission intervals, the results obtained with the Kr + Au system at 43 and 60 A.MeV are presented. The experiments were performed with the NAUTILUS exclusive detectors. Central collisions were selected by means of a relative velocity criterion to reject the events containing a forward emitted fragment. For the two bombardment energies the data analysis shows that the formation of a compound of mass around A = 200. By comparing the fragment dynamical variables with simulations one can conclude about the simultaneity of the compound deexcitation processes. It was found that a 5 MeV/A is able to reproduce the characteristics of the detected fragments. Also, it was found that to reproduce the dynamical characteristics of the fragments issued from central collisions it was not necessary to superimpose a radial collective energy upon the Coulomb and thermal motion. The distribution of the relative angles between detected fragments is used here as a chronometer. For simultaneous ruptures the small relative angles are forbidden by the Coulomb repulsion, while for sequential processes this interdiction is the more lifted the longer the interval between the two emissions is. For the system discussed here the comparison between simulation and data has been carried out for the extreme cases, i.e. for a vanishing and infinite time interval between the two emissions, respectively. More sophisticated simulations to describe angular distributions between the emitted fragments were also developed 2 refs.

  18. Solvent: A Key in Digestive Ripening for Monodisperse Au Nanoparticles

    Science.gov (United States)

    Wang, Peng; Qi, Xuan; Zhang, Xuemin; Wang, Tieqiang; Li, Yunong; Zhang, Kai; Zhao, Shuang; Zhou, Jun; Fu, Yu

    2017-01-01

    This work has mainly investigated the influence of the solvent on the nanoparticles distribution in digestive ripening. The experiments suggested that the solvents played a key role in digestive ripening of Au nanoparticles (Au NPs). For the benzol solvents, the resulting size distribution of Au NPs was inversely related to the solvent polarity. It may be interpreted by the low Gibbs free energy of nanoparticles in the high polarity medium, which was supposedly in favor of reducing the nanoparticles distribution. Through digestive ripening in the highly polar benzol solvent of p-chlorotoluene, monodisperse Au NPs with relative standard deviation (RSD) of 4.8% were achieved. This indicated that digestive ripening was an effective and practical way to prepare high-quality nanoparticles, which holds great promise for the nanoscience and nanotechnology.

  19. Fe magnetic impurity effect in Au atomic sized conductor

    Energy Technology Data Exchange (ETDEWEB)

    Ienaga, Koichiro; Inagaki, Yuji; Kawae, Tatsuya [Department of Applied Quantum Physics, Kyushu University, Moto-oka, Fukuoka 819-0395 (Japan); Tsujii, Hiroyuki, E-mail: te208276@s.kyushu-u.ac.j [Department of Education, Kanazawa University, Kanazawa, 920-1192 (Japan)

    2010-01-01

    We have studied the electrical conductance in Au nanowire containing 0.07 at.%Fe ions (AuFe nanowire) with mechanically controllable break junction technique to investigate the magnetic impurity effects in the atomic-sized conductance. At room temperature, we observe not only conductance steps at the integer multiples of G{sub 0} = 2e{sup 2}/h, but also steps deviating from them in AuFe nanowire. Moreover, these features persist down to T = 4.2 K. The scattering between the conduction electrons and Fe magnetic ions may lift the spin degeneracy of the transmission probability, which is responsible for the deviation. Zero bias anomaly is observed in the AuFe nanowire with the contact diameter larger than {approx}3 nm in the current-voltage (I-V) measurements at T = 4.2 K, which may be caused by Kondo effect.

  20. Hydrogen adsorption on bimetallic PdAu(111) surface alloys

    DEFF Research Database (Denmark)

    Takehiro, Naoki; Liu, Ping; Bergbreiter, Andreas

    2014-01-01

    The adsorption of hydrogen on structurally well defined PdAu-Pd(111) monolayer surface alloys was investigated in a combined experimental and theoretical study, aiming at a quantitative understanding of the adsorption and desorption properties of individual PdAu nanostructures. Combining the stru...... into the physical effects underlying the observed adsorption behavior. Consequences of these findings for the understanding of hydrogen adsorption on bimetallic surfaces in general are discussed.......The adsorption of hydrogen on structurally well defined PdAu-Pd(111) monolayer surface alloys was investigated in a combined experimental and theoretical study, aiming at a quantitative understanding of the adsorption and desorption properties of individual PdAu nanostructures. Combining...... and high resolution electron energy loss spectroscopy (HREELS) provides conclusions on the minimum ensemble size for dissociative adsorption of hydrogen and on the adsorption energies on different sites active for adsorption. Density functional theory (DFT) based calculations give detailed insight...

  1. On the structure of the thiolated Au15 cluster.

    Science.gov (United States)

    Tlahuice-Flores, Alfredo; Jose-Yacamán, Miguel; Whetten, Robert L

    2013-12-07

    The structure of the Au15-thiolate cluster has been elucidated using a DFT approach, and it is demonstrated to comprise a Au4-tetrahedron core protected solely by the combination of two concatenated staple motifs. The longer motif efficiently wraps the core, and threads the shorter one. The structural assignment is supported by comparison to the powder X-ray diffraction pattern and, via time dependent-DFT calculations, to the optical and chiroptical (CD) absorption spectra. The calculated CD spectrum features a characteristic strong peak centered at 3.48 eV in accordance with the experimental profile. These results confirm the existence of long Au(I)-thiolate motifs as protecting units of small thiolated gold clusters with a thiolate-to-gold ratio comparable to the Au15(SR)13 cluster.

  2. Malformations vasculaires au cours du syndrome de Williams-Beuren

    African Journals Online (AJOL)

    Malformations vasculaires au cours du syndrome de Williams-Beuren: à propos de trois nouvelles observations. Hicham Sator, Fatima Ezzahra Rhouni, Ibitihale Benjouad, Fatima Ezzahra Rhouni, Ibitihale Benjouad, Rachida Dafiri, Latifa Chat ...

  3. Assembling Bare Au Nanoparticles at Positively Charged Templates

    Science.gov (United States)

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

    2016-05-01

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the charged-interfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits short-range in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), display less in-plane regular packing compared to bare AuNPs.

  4. Assembling Bare Au Nanoparticles at Positively Charged Templates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

    2016-05-26

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the chargedinterfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits shortrange in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), display less in-plane regular packing compared to bare AuNPs.

  5. Café-au-lait spots in schoolchildren.

    Science.gov (United States)

    Burwell, R G; James, N J; Johnston, D I

    1982-01-01

    This paper reports a study of café-au-lait spots of a minimum diameter of 1 cm in 732 white schoolchildren. Three groups were identified, according to the number of café-au-lait spots on each child: (1) those with none (74%), (2) those with fewer than 5 (25%), and (3) those with at least 5 (5 children, 2 considered to be normal, and 3 siblings each presumed to have neurofibromatosis, one having died from leukaemia). Excluding the last group, the number of café-au-lait spots in the sample was not significantly related to age or sex. Some support is given for using the number of café-au-lait spots as an empirical threshold to diagnose neurofibromatosis. PMID:6810767

  6. Prolonged reorganization of thiol-capped Au nanoparticles layered structures

    Directory of Open Access Journals (Sweden)

    Sarathi Kundu

    2013-09-01

    Full Text Available Prolonged reorganization behaviour of mono-, di-, tri- and multi-layer films of Au nanoparticles prepared by Langmuir-Blodgett method on hydrophobic Si(001 substrates have been studied by using X-ray scattering techniques. Out-of-plane study shows that although at the initial stage the reorganization occurs through the compaction of the films keeping the layered structure unchanged but finally all layered structures modify to monolayer structure. Due to this reorganization the Au density increases within the nanometer thick films. In-plane study shows that inside the reorganized films Au nanoparticles are distributed randomly and the particle size modifies as the metallic core of Au nanoparticles coalesces.

  7. Ordered Au Nanodisk and Nanohole Arrays: Fabrication and Applications

    KAUST Repository

    Zheng, Yue Bing

    2010-01-01

    We have utilized nanosphere lithography (NSL) to fabricate ordered Au nanodisk and nanohole arrays on substrates and have studied the localized surface plasmon resonance (LSPR) of the arrays. Through these investigations, we demonstrate that the angle- dependent behavior of the LSPR in the Au nanodisk arrays enables real-time observation of exciton-plasmon couplings. In addition, we show that the NSL-fabricated Au nanohole arrays can be applied as templates for patterning micro-/nanoparticles under capillary force. The unique structural and plasmonic characteristics of the Au nanodisk and nano- hole arrays, as well as the low-cost and high-throughput NSL-based nanofabrication technique, render these arrays excellent platforms for numerous engineering applications. © 2010 by ASME.

  8. Programmes de nutrition au sein des centres de sante ...

    African Journals Online (AJOL)

    Au Mali, l'incidence de l'anémie ferriprive au cours de la grossesse est élevée. Pour contribuer à la réduction de cette anémie, un projet visant à renforcer les connaissances des professionnels de la santé en nutrition périnatale et sensibiliser les femmes enceintes pour une bonne supplémentation en fer/folate a été initié ...

  9. Chirurgie endoscopique de l'appareil urinaire au CHU Sylvanus ...

    African Journals Online (AJOL)

    Après un bilan assez limite, des cinq (05) dernières années des activités de chirurgie endoscopique sur l'appareil urinaire, au CHU SO, cette étude analyse les résultats, fait l'état des lieux du matériel endoscopique disponible, des ressources biomédicales au Togo puis situe la place de la maintenance biomédicale dans ...

  10. Relance de l'aquaculture au Sri Lanka | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    29 avr. 2016 ... Au Sri Lanka, le gouvernement a pour objectif de doubler la consommation de poisson par personne, de 11 kilos à 22 kilos par année, d'ici à la fin de 2014, afin d'augmenter la teneur en protéines du régime alimentaire. Aussi des chercheurs de la Wayamba University, au Sri Lanka, de l'Université de ...

  11. Opportunistes du VIH/SIDA en milieu hospitalier neurologique au ...

    African Journals Online (AJOL)

    Introduction La morbi-mortalité au cours du VIH/sida est souvent liée à des infections opportunistes (IO) neurologiques. L'objectif de cette étude est de déterminer en milieu hospitalier neurologique au Togo, les principales IO et celles qui sont liées à un fort taux de létalité. Méthodes Il s'agissait d'une étude descriptive ...

  12. L'entrepreneuriat au Canada dans le contexte mondial | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    24 nov. 2014 ... Également selon le rapport, au Canada, les immigrants de première génération se lancent en affaires dans une proportion plus élevée que le reste de la population, et les femmes participent davantage à l'activité entrepreneuriale que dans les autres pays du G7. En outre, au Canada, contrairement à ce ...

  13. Gouvernance et gestion des ressources communes au Vietnam ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Gouvernance et gestion des ressources communes au Vietnam. La subvention permettra au Collège d'agriculture et de foresterie de l'Université de Huê de se pencher sur des questions reliées à la gestion des ressources communes et à la pauvreté dans un contexte de décentralisation dans le centre du Vietnam. Le projet ...

  14. Soutien institutionnel au Centre for Population and Environmental ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le Centre for Population and Environmental Development (CPED), établi au Nigeria, est un organisme indépendant à but non lucratif qui a été constitué officiellement en 1998. Il se consacre à la recherche-action sur la réduction de la pauvreté et le développement durable au Nigeria en général et dans la région du delta ...

  15. Tabac et pauvreté au Niger | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Tabac et pauvreté au Niger. La majorité des pays africains sud du Sahara sont au premier stade de l'épidémie du tabac mais la consommation du tabac augmente rapidement. Consciente de la menace mondiale, l'Organisation mondiale de santé (OMS) a initié la Convention-cadre pour la lutte anti-tabac et la majorité des ...

  16. Intrinsic spin Seebeck effect in Au/YIG.

    Science.gov (United States)

    Qu, D; Huang, S Y; Hu, Jun; Wu, Ruqian; Chien, C L

    2013-02-08

    The acute magnetic proximity effects in Pt/YIG compromise the suitability of Pt as a spin current detector. We show that Au/YIG, with no anomalous Hall effect and a negligible magnetoresistance, allows the measurements of the intrinsic spin Seebeck effect with a magnitude much smaller than that in Pt/YIG. The experiment results are consistent with the spin polarized density functional calculations for Pt with a sizable and Au with a negligible magnetic moment near the interface with YIG.

  17. Programmation religieuse au Moyen-Orient : analyse du contenu de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Depuis dix ans, la télévision contribue beaucoup au façonnement des attitudes au Moyen-Orient. Dans un contexte de gouvernements autoritaires, d'instabilité politique, de guerre et d'interventions militaires étrangères récurrentes, la télévision a permis la diffusion d'opinions et de points de vue qui, autrement, auraient ...

  18. EST Table: AU311143 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available AU311143 TT1-27 11/12/09 GO hit GO:0000785(chromatin)|GO:0003682(chromatin binding)...|GO:0005634(nucleus)|GO:0006333(chromatin assembly or disassembly) 10/09/28 n.h 10/08/28 n.h 10/08/27 n.h 10/09/10 n.h 10/09/10 n.h 10/09/10 n.h AU311143 L7 ...

  19. L'entrepreneuriat au Canada dans le contexte mondial | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Également selon le rapport, au Canada, les immigrants de première génération se lancent en affaires dans une proportion plus élevée que le reste de la population, et les femmes participent davantage à l'activité entrepreneuriale que dans les autres pays du G7. En outre, au Canada, contrairement à ce que l'on observe ...

  20. Alloying Au surface with Pd reduces the intrinsic activity in catalyzing CO oxidation

    KAUST Repository

    Qian, Kun

    2016-03-30

    © 2016. Various Au-Pd/SiO2 catalysts with a fixed Au loading but different Au:Pd molar ratios were prepared via deposition-precipitation method followed by H2 reduction. The structures were characterized and the catalytic activities in CO oxidation were evaluated. The formation of Au-Pd alloy particles was identified. The Au-Pd alloy particles exhibit enhanced dispersions on SiO2 than Au particles. Charge transfer from Pd to Au within Au-Pd alloy particles. Isolated Pd atoms dominate the surface of Au-Pd alloy particles with large Au:Pd molar ratios while contiguous Pd atoms dominate the surface of Au-Pd alloy particles with small Au:Pd molar ratios. Few synergetic effect of Au-Pd alloy occurs on catalyzing CO oxidation under employed reaction conditions. Alloying Au with Pd reduces the intrinsic activity in catalyzing CO oxidation, and contiguous Pd atoms on the Au-Pd alloy particles are capable of catalyzing CO oxidation while isolated Pd atoms are not. These results advance the fundamental understandings of Au-Pd alloy surfaces in catalyzing CO oxidation.

  1. Study on antibacterial activity of chemically synthesized PANI-Ag-Au nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Boomi, Pandi [Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi 630 003, Tamil Nadu (India); Prabu, Halliah Gurumallesh, E-mail: hgprabu2010@gmail.com [Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi 630 003, Tamil Nadu (India); Manisankar, Paramasivam [Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi 630 003, Tamil Nadu (India); Ravikumar, Sundaram [Department of Oceanography and Coastal Area Studies, School of Marine Sciences, Alagappa University, Thondi Campus 623 409, Tamil Nadu (India)

    2014-05-01

    Graphical abstract: - Highlights: • New method of synthesizing PANI-Ag-Au nanocomposite. • Surface Plasmon resonance and formation of composite at nano level were analyzed. • HR-TEM study revealed uniform distribution of nanoparticles. • PANI-Ag-Au nanocomposite exhibited good antibacterial activity. - Abstract: Pristine polyaniline (PANI), PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites have been successfully synthesized by chemical oxidative polymerization method using aniline as monomer, ammonium persulphate as oxidant and metal (Ag, Au and Ag-Au) colloids. UV-Vis analysis exhibited surface Plasmon resonances of Ag, Au, Ag-Au nanoparticles. FT-IR spectra revealed the shift in peak position of N-H stretching. X-ray diffraction (XRD) results confirm the presence of Ag, Au and Au-Ag nanoparticles. HR-TEM images show nanosizes of Ag, Au, Ag-Au and the incorporation of such nanoparticles into the PANI matrix. Pristine PANI, PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites were tested for antibacterial activity by agar well diffusion method. PANI-Ag-Au nanocomposite exhibited higher antibacterial activity against both gram-positive [Streptococcus sp. (MTCC 890), Staphylococcus sp. (MTCC 96)] and gram-negative bacteria [Escherichia coli (MTCC 1671) and Klebsiella sp. (MTCC 7407)] when compared with PANI-Ag nanocomposite, PANI-Au nanocomposite and pristine PANI. The novelty of this study is the polymer-bimetal synthesis and its antibacterial potential.

  2. Au nanoparticles decorated graphene/nickel foam nanocomposite for sensitive detection of hydrogen peroxide

    National Research Council Canada - National Science Library

    Xiaojuan Wang Xinli Guo Jian Chen Chuang Ge Hongyi Zhang Yuanyuan Liu Li Zhao Yao Zhang Zengmei Wang Litao Sun

    The Au nanoparticles decorated graphene(AuNPs@Gr)/nickel foam(Gr/NiF) nanocomposite(AuNPs@Gr/NiF) was prepared by chemical vapor deposition followed by electrophoretic deposition of AuNPs on Gr/NiF...

  3. Reconstruction and study of the multi-strange baryons in ultra-relativistic heavy ion collisions at a center-of-mass energy of 200 GeV, with the Star experiment at RHIC; Reconstruction et etude des baryons multi-etranges dans les collisions d'ions lourds ultra-relativistes a {radical}S{sub NN} = 200 GeV avec l'experience STAR au RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Faivre, J

    2004-10-15

    The study of strangeness production is essential for the understanding of processes occurring in ultra-relativistic heavy ion collisions. Strangeness production is directly linked to the phase of deconfined partons that followed these collisions: the quark and gluon plasma. STAR, one of the 4 experiments at RHIC collider, is a perfect tool for studying the multi-strange {xi} and {omega} particles. We have devised a {xi} and {omega} reconstruction program using signals from the STAR time projection chamber. We have worked out a multi-variable selection method for extracting the signals from the combinative background: the linear discriminant analysis. We have applied it to Au-Au collisions at 200 GeV (in the center of mass frame) to improve the accuracy of previous results. The {omega} and anti-{omega} production rates have been obtained for 3 ranges of centrality as well as their radial flow and their kinetic uncoupling temperatures. The gain on the relative uncertainty is between 15 and 30% according to the variable. The average speed of the radial flow is 0.50 {+-} 0.02 and the kinetic uncoupling temperature is 132 {+-} 20 MeV which indicates that multi-strange baryons uncouple in hadronic medium earlier that lighter particles like pions, kaons and protons. However, uncertainty intervals remain too broad to draw strong conclusions. (A.C.)

  4. Controlled electrodeposition of Au monolayer film on ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qiang; Pang, Liuqing; Li, Man; Zhang, Yunxia; Ren, Xianpei [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Liu, Shengzhong Frank, E-mail: szliu@dicp.ac.cn [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023 (China)

    2016-05-15

    Highlights: • We fabricate Au monolayer film on Ionic liquid substrate using an electrochemical deposition technique. • Au monolayer film was deposited on a “soft substrate” for the first time. • Au monolayer film can contribute extra Raman enhancement. - Abstract: Gold (Au) nanoparticles have been attractive for centuries for their vibrant appearance enhanced by their interaction with sunlight. Nowadays, there have been tremendous research efforts to develop them for high-tech applications including therapeutic agents, sensors, organic photovoltaics, medical applications, electronics and catalysis. However, there remains to be a challenge to fabricate a monolayer Au coating with complete coverage in controlled fashion. Here we present a facile method to deposit a uniform Au monolayer (ML) film on the [BMIM][PF{sub 6}] ionic liquid substrate using an electrochemical deposition process. It demonstrates that it is feasible to prepare a solid phase coating on the liquid-based substrate. Moreover, the thickness of the monolayer coating can be controlled to a layer-by-layer accuracy.

  5. Transient FTIR spectroscopy for probing reaction pathways on Au catalysts

    Science.gov (United States)

    Overbury, Steven H.

    2008-03-01

    Au is now well known to be an active catalyst if the Au particles are sufficiently small, less than about 5 nm. The causes for this structure sensitivity are now beginning to be better understood. Computational modeling and measurements of size dependence on a single catalyst are consistent with activity at sites with low coordination numbers, due in part to flexibility of adsorbate geometry in these sites. Although small size and low coordinate sites are important in catalyzing, e.g. the CO oxidation reaction, there appear to be other factors which control the observed activity as demonstrated by catalyst deactivation and unusual temperature dependence. We have performed studies of CO oxidation over Au/TiO2, Au/SiO2, Au/ZnO/TiO2 and Au/FePO4 catalysts to explore reaction pathways and the causes for activation and deactivation. Three different reactor systems, a fast gas transient FTIR spectrometer, a slower transient DRIFTS cell and a steady state plug flow reactor have been used to correlate activity with surface species. Using this operando approach the elementary steps in the CO oxidation reaction have been explored. Striking differences between the supports are found. The effect of various pre-treatments, the evolution of the surface species during ``steady state'' reaction and the role of carbonate, oxygen storage, water, hydroxyl upon catalyst activation and deactivation have been explored and will be described. Reaction pathways and mechanisms will be proposed and compared for the different catalysts.

  6. Biosupported Bimetallic Pd Au Nanocatalysts for Dechlorination of Environmental Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    De Corte, S.; Fitts, J.; Hennebel, T.; Sabbe, T.; Bliznuk, V.; Verschuere, S.; van der Lelie, D.; Verstraete, W.; Boon, N.

    2011-08-30

    Biologically produced monometallic palladium nanoparticles (bio-Pd) have been shown to catalyze the dehalogenation of environmental contaminants, but fail to efficiently catalyze the degradation of other important recalcitrant halogenated compounds. This study represents the first report of biologically produced bimetallic Pd/Au nanoparticle catalysts. The obtained catalysts were tested for the dechlorination of diclofenac and trichloroethylene. When aqueous bivalent Pd(II) and trivalent Au(III) ions were both added to concentrations of 50 mg L{sup -1} and reduced simultaneously by Shewanella oneidensis in the presence of H{sub 2}, the resulting cell-associated bimetallic nanoparticles (bio-Pd/Au) were able to dehalogenate 78% of the initially added diclofenac after 24 h; in comparison, no dehalogenation was observed using monometallic bio-Pd or bio-Au. Other catalyst-synthesis strategies did not show improved dehalogenation of TCE and diclofenac compared with bio-Pd. Synchrotron-based X-ray diffraction, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the simultaneous reduction of Pd and Au supported on cells of S. oneidensis resulted in the formation of a unique bimetallic crystalline structure. This study demonstrates that the catalytic activity and functionality of possibly environmentally more benign biosupported Pd-catalysts can be improved by coprecipitation with Au.

  7. Spin Polarization and Quantum Spins in Au Nanoparticles

    Directory of Open Access Journals (Sweden)

    Wen-Hsien Li

    2013-08-01

    Full Text Available The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter.

  8. Au/Fe/Au multilayer transducers for magneto-optic surface plasmon resonance sensing

    Science.gov (United States)

    Regatos, D.; Fariña, D.; Calle, A.; Cebollada, A.; Sepúlveda, B.; Armelles, G.; Lechuga, L. M.

    2010-09-01

    In this paper, we analyze the magnetoplasmonic (MP) features and sensing capabilities of Au/Fe/Au trilayer structures, as transducers of the magneto-optic surface plasmon resonance (MOSPR) biosensor. This biosensor, which can surpass the sensitivity of the standard SPR sensor, is based on a MP modulation technique generated by the simultaneous stimulation of the surface plasmon polaritons (SPP) and the transversal magneto-optical Kerr effect (TMOKE). We study the magneto-optical activity of the trilayers as a function of the thickness and position of the Fe layer. We first demonstrate that this kind of structure allows modulating the SPP through an external magnetic field and moreover, induce a strong enhancement of the TMOKE effect. The modulation of the SPP is linearly proportional to the thickness of Fe layer and inversely proportional to the distance between the Fe layer and the external dielectric medium. Finally, we experimentally confirm a twofold increase in the MOSPR sensitivity with respect to the intensity-interrogated SPR biosensor in bulk refractive-index changes, keeping a similar chemical resistance and stability, unprecedented in other MP transducers, and biofunctionalization protocols.

  9. Multi-spacecraft observations of ICMEs propagating from 1 AU to 1.5 AU

    Science.gov (United States)

    Guo, J.; von Forstner, J.; Wimmer-Schweingruber, R. F.; Hassler, D.; Zeitlin, C. J.; Ehresmann, B.; Lohf, H.; Appel, J. K.; Heber, B.; Steigies, C. T.; Jian, L.

    2016-12-01

    The Radiation Assessment Detector (RAD) instrument on the Curiosity rover (Mars Science Laboratory mission) has been measuring galactic cosmic rays on the surface of Mars since its landing 4 years ago. Using this data, we can detect Forbush decreases caused by ICMEs passing Mars. To gain a better understanding of the propagation of individual ICMEs from 1 AU (Earth orbit) to 1.5 AU (Mars orbit), we investigate events that took place close to the oppositions of Earth (as well as STEREO A and B) and Mars, i.e., when they were nearly in a straight line on the same side of the Sun in the ecliptic plane. Such lineups allow us to estimate the ICMEs' transit time by estimating the delay time of the corresponding Forbush decreases between data from Earth's orbit (such as neutron monitors on Earth and HEP on both STEREOs) and Mars (RAD). Based on the radial distance between the two measurement locations, the ambient solar wind speeds and the properties of these ICMEs determined in previous studies, we investigate the evolution of the ICME's speed and/or shape during its propagation in the interplanetary medium beyond Earth orbit.

  10. Electrochemical Investigations of 4-Methoxypyridine Adsorption on Au(111) Predict Its Suitability for Stabilizing Au Nanoparticles.

    Science.gov (United States)

    Unni, Bipinlal; Simon, Sajna; Burgess, Ian J

    2015-09-15

    A thermodynamic analysis of the adsorption of 4-methoxypyridine (MOP) on Au(111) surfaces is presented in an effort to determine its propensity to stabilize metal nanoparticles. The adsorption of MOP is compared and contrasted to the adsorption of 4-dimethylaminopyridine (DMAP), the latter of which is well-known to form stable Au nanoparticles. Electrochemical studies show that MOP, like most pyridine derivatives, can exhibit two different adsorption states. The electrical state of the metal, the pH of the solution, and the surface crystallography determine whether MOP adopts a low-coverage, π-bonded orientation or a high-coverage, σ-type orientation. A modified Langmuir adsorption isotherm is used to extract free energies of adsorption which are roughly 10% stronger for DMAP compared to MOP at equivalent conditions when expressed on a rational basis. The higher adsorption strength is attributed to DMAP's greater Lewis basicity. Qualitatively, MOP and DMAP adsorption are found to be completely analogous, implying that MOP-protected gold particles should be stable under conditions that favor the high-coverage adsorption state. Using a previously reported, single-phase synthesis, this is shown to be the case.

  11. Synthesis of Au/C and Au/Pani for anode electrodes in glucose microfluidic fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Balcazar, M.; Morales-Acosta, D.; Castaneda, F.; Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, 76703 Queretaro (Mexico); Ledesma-Garcia, J. [Division de Investigacion y Posgrado, Facultad de Ingenieria, Universidad Autonoma de Queretaro, 76010 Queretaro (Mexico)

    2010-06-15

    Gold nanoparticles have been prepared by two methods: chemical (ex-situ, Au/C) by two phase protocol, and electrochemical (in-situ, Au/Pani) by electroreduction of gold ions on a polyaniline film and compared as anode catalysts in a glucose microfluidic fuel cell. In this paper the structural characteristics and electrocatalytic properties were investigated by X-ray diffraction and electrochemical measurements. The catalytic behavior of both anodes was tested in a microfluidic fuel cell with a reference electrode incorporated, by means of linear sweep voltammetry (LSV), showing a cathodic shift in the glucose oxidation peak for Au/Pani. Results show a higher power density (0.5 mW cm{sup -} {sup 2}) for Au/C anode compared with an already reported value, where a glucose microfluidic fuel cell was used in similar conditions. (author)

  12. Wetting - Dewetting Transitions of Au/Ni Bilayer Films

    Science.gov (United States)

    Cen, Xi

    Thin films deposited at low temperatures are often kinetically constrained and will dewet the underlying substrate when annealed. Solid state dewetting is driven by the minimization of the total free energy of thin film-substrate interface and free surface, and mostly occurs through surface diffusion. Dewetting is a serious concern in microelectronics reliability. However, it can also be utilized for the self-assembly of nanostructures with potentials in storage, catalysis, or transistors. Therefore, a fundamental understanding of the dewetting behavior of thin metal films is critical for improving the thermal stability of microelectronics and controlling the order of self-assembled nanostructures. Mechanisms for dewetting of single layer films have been studied extensively. However little work has been reported on multilayer or alloyed thin films. In the thesis, the solid state dewetting of Au/Ni bilayer films deposited on SiO2/Si substrates was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and aberration corrected scanning TEM (STEM). Ex-situ SEM and TEM studies were performed with in-situ TEM heating characterization to identify the mechanisms during the dewetting process of Au/Ni bilayer films. The solid state dewetting of Au/Ni bilayer films from SiO2/Si substrates exhibits both homogeneous and localized dewetting of Ni and long-edge retraction for Au under isothermal annealing condition. The top Au layer retracts up to 1 mm from the edge of the substrate wafer to reduce the energetically unfavored Au/Ni interface. In contrast, Ni dewets and agglomerates locally due to its limited diffusivity compared to Au. Film morphology and local chemical composition varies significantly across hundreds of microns along the direction normal to the retracting edge. Besides long range edge receding, localized dewetting shows significant changes in film morphology and chemical distribution. Both Au and Ni shows texturing. Despite

  13. Unique Properties of Core Shell Ag@Au Nanoparticles for the Aptasensing of Bacterial Cells

    OpenAIRE

    Ezat Hamidi-Asl; Freddy Dardenne; Sanaz Pilehvar; Ronny Blust; Karolien De Wael

    2016-01-01

    In this article, it is shown that the efficiency of an electrochemical aptasensing device is influenced by the use of different nanoparticles (NPs) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silver–gold core shell (Ag@Au), gold–silver core shell (Au@Ag), and silver–gold alloy nanoparticles (Ag/Au). Among these nanomaterials, Ag@Au core shell NPs are advantageous for aptasensing applications because the core impro...

  14. Amperometric Immunosensor for Carbofuran Detection Based on MWCNTs/GS-PEI-Au and AuNPs-Antibody Conjugate

    Directory of Open Access Journals (Sweden)

    Xiangyou Wang

    2013-04-01

    Full Text Available In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au nanocomposites were modified onto the surface of a glass carbon electrode (GCE via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD, ultraviolet and visible absorption spectroscopy (UV-vis and scanning electron microscopy (SEM, respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3. The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication.

  15. Au crystal growth on natural occurring Au-Ag aggregate elucidated by means of precession electron diffraction (PED)

    Science.gov (United States)

    Roqué Rosell, Josep; Portillo Serra, Joaquim; Aiglsperger, Thomas; Plana-Ruiz, Sergi; Trifonov, Trifon; Proenza, Joaquín A.

    2018-02-01

    In the present work, a lamella from an Au-Ag aggregate found in Ni-laterites has been examined using Transmission Electron Microscope to produce a series of Precision Electron Diffraction (PED) patterns. The analysis of the structural data obtained, coupled with Energy Dispersive X-ray microanalysis, made it possible to determine the orientation of twinned native gold growing on the Au-Ag aggregate. The native Au crystal domains are found to have grown at the outermost part of the aggregate whereas the inner core of the aggregate is an Au-Ag alloy (∼4 wt% Ag). The submicron structural study of the natural occurring Au aggregate points to the mobilization and precipitation of gold in laterites and provides insights on Au aggregates development at supergene conditions. This manuscript demonstrates the great potential of electron crystallographic analysis, and in particular, PED to study submicron structural features of micron sized mineral aggregates by using the example of a gold grain found in a Ni-laterite deposits.

  16. Effect of Au nano-particle aggregation on the deactivation of the AuCl3/AC catalyst for acetylene hydrochlorination

    Science.gov (United States)

    Dai, Bin; Wang, Qinqin; Yu, Feng; Zhu, Mingyuan

    2015-05-01

    A detailed study of the valence state and distribution of the AuCl3/AC catalyst during the acetylene hydrochlorination deactivation process is described and discussed. Temperature-programmed reduction and X-ray photoelectron spectral analysis indicate that the active Au3+ reduction to metallic Au0 is one reason for the deactivation of AuCl3/AC catalyst. Transmission electron microscopy characterization demonstrated that the particle size of Au nano-particles increases with increasing reaction time. The results indicated that metallic Au0 exhibits considerable catalytic activity and that Au nano-particle aggregation may be another reason for the AuCl3/AC catalytic activity in acetylene hydrochlorination.

  17. First-principles study of the binary intermetallics in the Au-Rb system

    Science.gov (United States)

    Benmechri, Achraf; Djaballah, Yassine; Amer, Ahmed Said; Belgacem-Bouzida, Aissa; Bouderba, Hichem

    2014-06-01

    First-principles calculations within density functional theory (DFT) with the projector augmented wave (PAW) technique were used to investigate the stabilities of intermetallics in the Au-Rb system at 0 K. Four intermetallics: Au7Rb3, Au3Rb2, Au5Rb and AuRb were investigated in their observed experimental structures. The Au2Rb compound, reported in the Au-Rb phase diagrams without specifying explicitly its structure, was also investigated by inspecting several hypothetical structures. A suspect compound (AuRb2) was also investigated. Results show that: (i) The Au3Rb2 and Au7Rb3 compounds, which were never reported in any Au-Rb phase diagram, are stable at 0 K. (ii) The Au2Rb compound is not a ground state for all the tested structures. (iii) Stability of the Au5Rb and AuRb compounds was confirmed. (iv) The new compound AuRb2, not yet reported experimentally, is found mechanically stable at 0 K.

  18. Thiol ligand-induced transformation of Au38(SC2H4Ph)24 to Au36(SPh-t-Bu)24.

    Science.gov (United States)

    Zeng, Chenjie; Liu, Chunyan; Pei, Yong; Jin, Rongchao

    2013-07-23

    We report a disproportionation mechanism identified in the transformation of rod-like biicosahedral Au38(SCH2CH2Ph)24 to tetrahedral Au36(TBBT)24 nanoclusters. Time-dependent mass spectrometry and optical spectroscopy analyses unambiguously map out the detailed size-conversion pathway. The ligand exchange of Au38(SCH2CH2Ph)24 with bulkier 4-tert-butylbenzenethiol (TBBT) until a certain extent starts to trigger structural distortion of the initial biicosahedral Au38(SCH2CH2Ph)24 structure, leading to the release of two Au atoms and eventually the Au36(TBBT)24 nanocluster with a tetrahedral structure, in which process the number of ligands is interestingly preserved. The other product of the disproportionation process, i.e., Au40(TBBT)m+2(SCH2CH2Ph)24-m, was concurrently observed as an intermediate, which was the result of addition of two Au atoms and two TBBT ligands to Au38(TBBT)m(SCH2CH2Ph)24-m. The reaction kinetics on the Au38(SCH2CH2Ph)24 to Au36(TBBT)24 conversion process was also performed, and the activation energies of the structural distortion and disproportionation steps were estimated to be 76 and 94 kJ/mol, respectively. The optical absorption features of Au36(TBBT)24 are interpreted on the basis of density functional theory simulations.

  19. Au3+/Au0 Supported on Chromium(III Terephthalate Metal Organic Framework (MIL-101 as an Efficient Heterogeneous Catalystfor Three-Component Coupling Synthesis of Propargylamines

    Directory of Open Access Journals (Sweden)

    Lili Liu

    2017-01-01

    Full Text Available Post-synthesis modification is a useful method for the functionalization of metal–organic frameworks (MOFs. A novel catalyst Au@MIL-101-ED-SA (ED = ethylenediamine, SA = salicylaldehyde, containing coexisting Au3+ ions and Au0 nanoparticles, was prepared successfully by post-synthesis modification with ethylenediamine, salicylaldehyde and gold. Gold nanoparticles supported on MIL-101 (Au@MIL-101 were prepared successfully by the impregnation method. Au@MIL-101-ED-SA and Au@MIL-101 were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Au@MIL-101-ED-SA and Au@MIL-101 were applied as environmentally friendly catalysts in the three-component coupling reaction of aldehydes, amines, and alkynes for the preparation of diverse propargylamines. Au@MIL-101-ED-SA contained a fraction of cationic gold (Au3+/Au0 = 0.9 and showed higher catalytic activity than Au@MIL-101, which was prepared by the impregnation method. Furthermore, the reactions were performed under heterogeneous conditions and the novel catalyst was successfully recycled for four consecutive runs.

  20. Au rendez-vous allemand (2

    Directory of Open Access Journals (Sweden)

    Agnès Bouvier

    2010-12-01

    Full Text Available La parution en 1857 des Études d’histoire religieuse d’Ernest Renan marque l’entrée en France des conceptions allemandes du mythe appliquées à l’histoire des textes sacrés. Or, cette date est aussi celle de la rencontre intellectuelle entre Renan et Flaubert, rencontre qui se matérialisera deux ans plus tard : au moment où Flaubert entreprend Salammbô, il accède aux travaux philologiques de la « nouvelle école » représentée en France par Renan. La supériorité de l’école allemande tient essentiellement selon Renan à sa capacité de penser le mythe comme un tout « indivis » irréductible à toute interprétation univoque : en dépit de certaines outrances des « rationalistes » et des « mythologues », dont il distingue nettement les deux types d’approche, Renan envisage l’exégèse allemande comme un progrès dont il montre les étapes et qu’il se propose d’achever en développant ce qu’il appelle une critique « sympathique ». Davantage qu’une méthode, il définit une posture critique d’adhésion à l’objet que Flaubert pourra mettre en oeuvre dans son roman.The publication in 1857 of Ernest Renan’s Études d’histoire religieuse signals the introduction in France of German ideas about myths applied to the history of religious texts. Now this date is also that of the intellectual encounter between Renan and Flaubert. Their actual meeting came about two years later. Indeed, while Flaubert was starting Salammbô, he discovered the philological studies of the “New School” represented in France by Renan. According to Renan the superiority of the German School was due to its capacity to comprehend the myth as an undivided whole irreducible to a univocal interpretation. Thus, despite the excesses of the “rationalists” and “mythologs”, whose methods he clearly distinguished, Renan considered the German exegesis a progress. He outlined its stages which he sought to complete by

  1. Structure investigation of organic molecules on Au(111) surfaces; Strukturuntersuchung organischer Molekuele auf Au(111)-Oberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Kazempoor, Michel

    2009-02-02

    The present work covers two topics namely the coadsorption of formic acid and water on Au(111) and the structure of biphenylalkanthiole SAMs on Au(111) surfaces. The coadsorption of formic acid and water on Au(111) surfaces has been investigated by means of vibrational and photoelectron spectroscopy (HREELS, XPS). Formic acid adsorbs at 90 K molecularly with vibrational modes characteristic for flat lying zig-zag chains in the mono- and multilayer regime, like in solid formic acid. The structure of the flat lying formic acid chains was determined by low energy electron diffraction (LEED) as a (2r3 x r19) unit cell. Annealing results in a complete desorption at 190 K. Sequential adsorption of formic acid and water at 90 K shows no significant chemical interaction. Upon annealing the coadsorbed layer to 140 K a hydrogenbonded cyclic complex of formic acid with one water molecule could be identified using isotopically labelled adsorbates. Upon further annealing this complex decomposes leaving molecularly adsorbed formic acid on the surface at 160 K, accompanied by a proton exchange between formic acid and water. The influence of the alkane spacer chain length on the structure of biphenylalkanethiols on Au(111) surfaces was investigated as well. A systematic study was done on BPn-SAMs deposited from the gas phase. For every chain length a structure was found by LEED. Furthermore the influence of temperature on the structure was investigated in the range from room temperature up to about 400 K. To obviate influences from different preparation methods BP3 and BP4 was deposited from gas phase and from solution. No LEED spots were observed on BP4 SAMs deposited from solution. For BP3 an influence of the preparation could be excluded. For all BPn-SAMs a good agreement between LEED and STM data's was found. Nevertheless different unit cells were determined by LEED and STM consistent structures could be suggested considering the unit cell size given by LEED and the

  2. Gestion des ressources minérales et conflits au Mali et au Niger

    OpenAIRE

    Deltenre, Damien

    2012-01-01

    Les ressources minérales représentent des secteurs importants des économies du Mali (or) et du Niger (uranium et pétrole). Dans le contexte incertain qui suit la crise libyenne de 2011 et l’effondrement du Mali début 2012, il convient d’étudier dans quelle mesure les richesses naturelles de ces deux pays possèdent un potentiel de prévention ou d’aggravation des conflits. La gestion malienne et nigérienne des ressources naturelles est examinée au départ d’un cadre analytique centré sur les not...

  3. Drowned reefs and antecedent karst topography, Au'au channel, S.E. Hawaiian Islands

    Science.gov (United States)

    Grigg, R.W.; Grossman, E.E.; Earle, S.A.; Gittings, S.R.; Lott, D.; McDonough, J.

    2002-01-01

    During the last glacial maximum (LGM), about 21,000 years ago, the Hawaiian Islands of Maui, Lanai, and Molokai were interconnected by limestone bridges, creating a super-island known as Maui-Nui. Approximately 120 m of sea-level rise during the Holocene Transgression flooded, and then drowned, these bridges separating the islands by inter-island channels. A new multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles. The concentric basins contain flat lagoon-like bottoms that are rimmed by steep-sided limestone walls. Undercut notches rim the basins at several depths, marking either sea-level still stands or paleo-lake levels. All of the solution basins shallower than 120 m were subaerial at the LGM, and at one stage or another may have been shallow shoreline lakes. Today, about 70 drowned reef pinnacles are scattered across the Maui-Lanai underwater bridge and all are situated in wave-sheltered positions. Most drowned during the interval between 14,000 and 10,000 years ago when sea-level rise averaged 15 mm/year. Virtually all of the surficial topography in the Au'au Channel today is a product of karst processes accentuated by marginal reef growth during the Holocene. Both the submerged basins and the drowned reefs represent an archive of sea-level and climate history in Hawaii during the late Quaternary.

  4. Relégation au village

    Directory of Open Access Journals (Sweden)

    Nicolas Renahy

    2010-12-01

    Full Text Available Les thèses de l’individualisation des sociétés occidentales, ou de l’exclusion de ceux qui resteraient en marge d’une vaste classe moyenne aux modes de vie homogénéisés, ont sans doute permis de sortir d’une grille de lecture rigide héritée du marxisme. Mais elles résistent aujourd’hui mal aux faits et sont vivement contredites par le renouvellement des études sur les inégalités sociales pensées en termes de stratification. Enquêtant la population ouvrière d’un village industriel de Bourgogne au cours des années 1990, l’auteur a pu mesurer tout autant la force socialisatrice continue du groupe ouvrier sur sa jeunesse que le lent processus de délitement de ses cadres de références, longtemps stabilisés autour d’une mono-industrie métallurgique, provoquant une crise dans la reproduction de ce monde ouvrier. C’est cette crise de reproduction qui est évoquée ici. Dans un premier temps sont explicitées les formes passées de la présence industrielle au village, qui n’a jamais été celle d’un bastion de la grande industrie – la population locale n’est pas structurellement différenciée de celle de son environnement rural immédiat. L’exemple d’une lignée familiale d’artisans montre pour finir l’étroit maillage entre usine et structures sociales plus classiquement rurales, favorisant la constitution d’un capital d’autochtonie, déclinaison populaire du capital social.Relegation to the villageArguments demonstrating the individualisation of western societies, or the exclusion of those who stay on the margins of a vast middle class homogeneous life style, have no doubt allowed the move away from the rigid interpretations inherited from Marxism. However, these arguments resist today in spite of the facts and they are even keenly contradicted by the renewal of stratification studies on social inequalities. Analyzing the working population of an industrial village in Bourgogne during the

  5. Synthesis of Au38(SCH2CH2Ph)24, Au36(SPh-tBu)24, and Au30(S-tBu)18 Nanomolecules from a Common Precursor Mixture.

    Science.gov (United States)

    Rambukwella, Milan; Dass, Amala

    2017-10-17

    Phenylethanethiol protected nanomolecules such as Au25, Au38, and Au144 are widely studied by a broad range of scientists in the community, owing primarily to the availability of simple synthetic protocols. However, synthetic methods are not available for other ligands, such as aromatic thiol and bulky ligands, impeding progress. Here we report the facile synthesis of three distinct nanomolecules, Au38(SCH2CH2Ph)24, Au36(SPh-tBu)24, and Au30(S-tBu)18, exclusively, starting from a common Aun(glutathione)m (where n and m are number of gold atoms and glutathiolate ligands) starting material upon reaction with HSCH2CH2Ph, HSPh-tBu, and HStBu, respectively. The systematic synthetic approach involves two steps: (i) synthesis of kinetically controlled Aun(glutathione)m crude nanocluster mixture with 1:4 gold to thiol molar ratio and (ii) thermochemical treatment of the purified nanocluster mixture with excess thiols to obtain thermodynamically stable nanomolecules. Thermochemical reactions with physicochemically different ligands formed highly monodispersed, exclusively three different core-size nanomolecules, suggesting a ligand induced core-size conversion and structural transformation. The purpose of this work is to make available a facile and simple synthetic method for the preparation of Au38(SCH2CH2Ph)24, Au36(SPh-tBu)24, and Au30(S-tBu)18, to nonspecialists and the broader scientific community. The central idea of simple synthetic method was demonstrated with other ligand systems such as cyclopentanethiol (HSC5H9), cyclohexanethiol(HSC6H11), para-methylbenzenethiol(pMBT), 1-pentanethiol(HSC5H11), 1-hexanethiol(HSC6H13), where Au36(SC5H9)24, Au36(SC6H11)24, Au36(pMBT)24, Au38(SC5H11)24, and Au38(SC6H13)24 were obtained, respectively.

  6. New systematic features in the neutron-deficient Au isotopes

    Science.gov (United States)

    Venhart, M.; Wood, J. L.; Sedlák, M.; Balogh, M.; Bírová, M.; Boston, A. J.; Cocolios, T. E.; Harkness-Brennan, L. J.; Herzberg, R.-D.; Holub, L.; Joss, D. T.; Judson, D. S.; Kliman, J.; Klimo, J.; Krupa, L.; Lušnák, J.; Makhathini, L.; Matoušek, V.; Motyčák, Š.; Page, R. D.; Patel, A.; Petrík, K.; Podshibyakin, A. V.; Prajapati, P. M.; Rodin, A. M.; Špaček, A.; Urban, R.; Unsworth, C.; Veselský, M.

    2017-07-01

    A recently developed portable, on-line capability for γ-ray and conversion-electron spectroscopy, HIGH-TATRA is demonstrated with its application to the study of 183Hg \\to 183Au at ISOLDE. Key details of the low-energy level scheme of the neutron-deficient nuclide 183Au populated in this decay are presented. A broad energy germanium detector is employed to achieve this (the first-ever use of such a device in decay-scheme spectroscopy), by way of a combination of high-gain γ-ray singles spectroscopy and γ-γ coincidence spectroscopy. Further, by combining the γ-r