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Sample records for bnl relativistic heavy

  1. Strangelet Search at the BNL Relativistic Heavy Ion Collider

    OpenAIRE

    Abelev, B. I.

    2008-01-01

    We have searched for strangelets in a triggered sample of 61 million central (top 4percent) Au+Au collisions at sqrt sNN = 200 GeV near beam rapidities at the STAR solenoidal tracker detector at the BNL Relativistic Heavy Ion Collider. We have sensitivity to metastable strangelets with lifetimes of order >_0.1 ns, in contrast to limits over ten times longer in BNL Alternating Gradient Synchrotron (AGS) studies and longer still at the CERN Super Proton Synchrotron (SPS). Upper limits of a few ...

  2. The BNL relativistic heavy ion collider (A new frontier in nuclear physics)

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider at Brookhaven is in its second year of construction with a target date for completion in late 1997. In this report, I will describe the status of the project, the designated milestones and the capabilities of this collider that set it apart as the premier facility to probe the new frontier of nuclear matter under extreme temperatures and densities

  3. The BNL Relativistic Heavy Ion Collider (A new frontier in nuclear physics)

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider at Brookhaven is in its second year of construction with a target date for completion in late 1997. In this report, I will describe the status of the project, the designated milestones and the capabilities of this collider that set it apart as the premier facility to probe the new frontier of nuclear matter under extreme temperatures and densities. Two large detectors and a pair of smaller detectors, which are in various stages of approval, form the experimental program at this point. They provide a complementary set of probes to study quark gluon plasma formation through different signatures. The two ring design of this collider allows for collisions between different ion species ranging from protons to gold

  4. Energy Dependence of Directed Flow over a Wide Range of Pseudorapidity in Au+Au Collisions at the BNL Relativistic Heavy Ion Collider

    Science.gov (United States)

    Back, B. 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.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, 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.; 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.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2006-07-01

    We report on measurements of directed flow as a function of pseudorapidity in Au+Au collisions at energies of sNN=19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the BNL Relativistic Heavy Ion Collider. These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.

  5. Relativistic heavy-ion physics: Experimental overview

    Indian Academy of Sciences (India)

    Itzhak Tserruya

    2003-04-01

    The field of relativistic heavy-ion physics is reviewed with emphasis on new results and highlights from the first run of the relativistic heavy-ion collider at BNL and the 15 year research programme at the super proton synchrotron (SPS) at CERN and the AGS at BNL.

  6. BNL heavy ion fusion program

    International Nuclear Information System (INIS)

    A principal attraction of heavy ion fusion is that existing accelerator technology and theory are sufficiently advanced to allow one to commence the design of a machine capable of igniting thermonuclear explosions. There are, however, a number of features which are not found in existing accelerators built for other purposes. The main thrust of the BNL Heavy Ion Fusion program has been to explore these features. Longitudinal beam bunching, very low velocity acceleration, and space charge neutralization are briefly discussed

  7. Chiral electric field in relativistic heavy-ion collisions at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

    Science.gov (United States)

    Zhong, Yang; Yang, Chun-Bin; Cai, Xu; Feng, Sheng-Qin

    2016-08-01

    It has been proposed that electric fields may lead to chiral separation in quark-gluon plasma (QGP). This is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both be completely produced in off-central nuclear-nuclear collision. We use the Woods-Saxon nucleon distribution to calculate the electric field distributions of off-central collisions. The chiral electric field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. The dependence of the electric field produced by the thermal quark in the central position with different impact parameters on the proper time with different collision energies in the RHIC and LHC energy regions are studied in this paper. Supported by National Natural Science Foundation of China (11375069, 11435054, 11075061, 11221504) and Key Laboratory Foundation of Quark and Lepton Physics (Hua-Zhong Normal University)(QLPL2014P01)

  8. Uniform description of bulk observables in the hydrokinetic model of A+A collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

    Science.gov (United States)

    Karpenko, Iu. A.; Sinyukov, Yu. M.; Werner, K.

    2013-02-01

    A simultaneous description of hadronic yields; pion, kaon, and proton spectra; elliptic flows; and femtoscopy scales in the hydrokinetic model of A+A collisions is presented at different centralities for the top BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) 2.76-TeV energies. The initial conditions are based on the Monte Carlo Glauber simulations. When going from RHIC to LHC energy in the model, the only parameters changed are the normalization of the initial entropy defined by the number of all charged particles in most central collisions, contribution to entropy from binary collisions, and barionic chemical potential. The hydrokinetic model is used in its hybrid version, which provides the correct match (at the isochronic hypersurface) of the decaying hadron matter evolution with hadronic ultrarelativistic quantum molecular dynamics cascade. The results are compared with the standard hybrid models where hydrodynamics and hadronic cascade are matching just at the non-space-like hypersurface of chemical freeze-out or on the isochronic hypersurface. The modification of the particle-number ratios at LHC caused, in particular, by the particle annihilations at the afterburn stage is also analyzed.

  9. Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

    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, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; 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.; 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, Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; 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, X.; 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.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; 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, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; 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.; 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.; 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.; Sandacz, A.; 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.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; 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.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; 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, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-08-01

    Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.

  10. Detectors for relativistic heavy-ion experiments

    International Nuclear Information System (INIS)

    We present in some detail an overview of the detectors currently used in relativistic heavy-ion research at the BNL AGS and the CERN SPS. Following that, a detailed list of RandD projects is given, including specific areas of work which need to be addressed in preparation for further experiments at the AGS and SPS for the upcoming experiments at RHIC

  11. Energy Dependence of Elliptic Flow over a Large Pseudorapidity Range in Au+Au Collisions at the BNL Relativistic Heavy Ion Collider

    Science.gov (United States)

    Back, B. 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.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, 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.; 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.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2005-04-01

    This Letter describes the measurement of the energy dependence of elliptic flow for charged particles in Au+Au collisions using the PHOBOS detector at the Relativistic Heavy Ion Collider. Data taken at collision energies of √(sNN)=19.6, 62.4, 130, and 200 GeV are shown over a wide range in pseudorapidity. These results, when plotted as a function of η'=|η|-ybeam, scale with approximate linearity throughout η', implying no sharp changes in the dynamics of particle production as a function of pseudorapidity or increasing beam energy.

  12. Magnetic-field-induced squeezing effect at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

    Science.gov (United States)

    Pang, Long-Gang; Endrődi, Gergely; Petersen, Hannah

    2016-04-01

    In off-central heavy-ion collisions, quark-gluon plasma (QGP) is exposed to the strongest magnetic fields ever created in the universe. Because of the paramagnetic nature of the QGP at high temperatures, the spatially inhomogeneous magnetic field configuration exerts an anisotropic force density that competes with the pressure gradients resulting from purely geometric effects. In this paper, we simulate (3+1)-dimensional ideal hydrodynamics with external magnetic fields to estimate the effect of this force density on the anisotropic expansion of the QGP in collisions at the Relativistic Heavy Ion Collider and at the Large Hadron Collider (LHC). While negligible for quickly decaying magnetic fields, we find that long-lived fields generate a substantial force density that suppresses the momentum anisotropy of the plasma by up to 20 % at the LHC energy and also leaves its imprint on the elliptic flow v2 of charged pions.

  13. Heavy Ion results from RHIC-BNL

    Directory of Open Access Journals (Sweden)

    Esumi Shinlchi

    2013-05-01

    Full Text Available Recent results from heavy ion collision experiments from RHIC at BNL are presented and discussed in terms of Quark Gluon Plasm properties, such as partonic collectivity and partonic energy loss. The experimental results with direct photons and heavy quarks have given important additional insights of the plasma on top of what has been known with light hadrons. Higher order event anisotropies and the related results have provided the geometrical, temporal and dynamical information of the plasma. The beam energy dependence of the various measurements could reveal the structure of QCD phase diagram and possibly the critical point in the diagram, where the properties of phase transition are expected to change drastically.

  14. [Relativistic heavy ion research

    International Nuclear Information System (INIS)

    This progress report describes the participation of members of the Nevis group in different experiments during the FY93 period. There was major involvement in: BNL/AGS experiment E802/859/866; BNL RHIC experiment PHENIX; and CERN/SPS experiment NA44. The group was also involved in the small scale experiment E858/878 at BNL/AGS. For the BNL/AGS experiment data collection is now complete, and the group is involved in data analysis. Contributions to systematic procedures for measuring and maintaining the high calibration of the time-of-flight system, along with the previously developed trigger system have been significant contributions to the physics which is beginning to emerge from this heavy ion experiment. The CERN experiment has published first results on S-Pb collisions, with emphasis on two particle correlations. The group has been actively involved in data collection this year. Emphasis is being placed on proton-proton interactions in S-Pb and proton-Pb collisions. The PHENIX experiment is aimed at measuring signatures of quark-gluon plasma. The Nevis group has been actively involved in this experiment from design of the time-of-flight and trigger system, to acting as experiment spokesman

  15. Production of light (anti)nuclei, (anti)hypertriton and di-$\\Lambda$ in central Au+Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

    CERN Document Server

    Xue, L; Chen, J H; Zhang, S; 10.1103/PhysRevC.85.064912

    2012-01-01

    A simple coalescence model is employed to investigate the production of light (anti)nuclei and (anti)hypertriton as well as di-$\\rm\\Lambda$ in the most central Au+Au collisions. The invariant yields of \\He(\\Hebar), \\hypert(\\hypertbar), and \\Hee(\\Heebar) obtained within current framework are found to be consistent with the measurements of the solenoidal tracker at the BNL Relativistic Heavy Ion Collider (STAR) detector. We also investigate the coalescence parameters $B_{A}$ (A = 2, 3, 4) as a function of transverse momentum for $d$(\\dbar), \\He(\\Hebar), \\hypert(\\hypertbar), and \\Hee(\\Heebar), respectively. $B_{2}$ for $d$(\\dbar) and $B_{3}$ for \\He(\\Hebar) are comparable with the STAR measurement within statistical uncertainties. The transverse momentum ($p_{T}$) integrated yields for di-$\\rm\\Lambda$ $dN_{\\Lambda\\Lambda}/dy \\sim 2.23\\times10^{-5}$, and is not strongly dependent on the parameter employed for the coalescence process. Combining the data points extracted by the PHENIX Collaboration, the coalescence...

  16. Relativistic heavy ion research

    International Nuclear Information System (INIS)

    Experimental work is reported on the following topics: transverse energy production in 10.7-GeV/c/u Au on Au collisions; first results on delta ray production and charged particle multiplicities with the Au beam at 10.7 GeV/c/A; preliminary studies on the feasibility of flow measurement with the E814 participant calorimeter; preliminary results from the E877 telescope; and low-pt baryon distribution in Si+Al, Pb collisions at the AGS. Then the status of the Hadronic Calorimeter project of AGS Experiment E864 (ECOS--Exotic Composite Object Spectrometer) is reviewed. Next, the same is done for work of the STAR RHIC collaboration (Silicon Vertex Tracker (SVT) project evolution and development in FY92, SVT software results from 1992, SVT instrumentation, FY93 SVT pion test beam). The instrumentation section deals with the design and installation of a target rapidity telescope for BNL experiment 814/877 and a repair scheme for the E814/E877 participant calorimeter. Finally, the theory part addresses bosonic kinetics: thermalization of mesons and the pion pperpendicular spectrum in ultrarelativistic heavy-ion collisions and non-equilibrium properties of hadronic mixtures

  17. QUARKONIUM PRODUCTION IN RELATIVISTIC NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 12

    Energy Technology Data Exchange (ETDEWEB)

    KHARZEEV,D.

    1999-04-20

    The RIKEN-BNL Workshop on Quarkonium Production in Relativistic Nuclear Collisions was held September 28--October 2, 1998, at Brookhaven National Laboratory. The Workshop brought together about 50 invited participants from around the world and a number of Brookhaven physicists from both particle and nuclear physics communities.

  18. Relativistic heavy ion research

    International Nuclear Information System (INIS)

    This report discusses the following topics: antiproton production; Bose-Einstein correlations; high-transverse momentum spectra; strangeness enhancement in heavy ion collisions; search for rare negative secondaries of antiprotons and antinuclei produced in heavy ion collisions; quark matter; and time-of-flight systems test at Brookhaven AGS. (LSP)

  19. Studies of relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    This report presents the progress in our program of Relativistic Heavy Ion studies. The first phase of experiments on lepton pairs is almost complete and the results from the initial part of this program are presented in copies of three publications. It appears that the origin of lepton pairs is the annihilation of pions. The evidence for this seems to be the shape of the dilepton mass spectrum, the cross-section as a function of energy which seems to scale with pion production, and the general kinematic behavior of the lepton pairs themselves. We present progress on the development of Ring Imaging Cerenkov counters for dilepton observations in general, and a short report on a high resolution method counter proposal that could be adapted to RHIC counters in general. Publication of results on hyperon polarization with incident polarized proton beams is also presented. These results use the phenomenological approach that could be useful in understanding hyperon production in heavy ion collisions. In this connection, a proposal for studying high density nuclear matter with incident antiprotons is presented. Progress on the TPC detectors developed by the BNL group for heavy ion research is reported, along with recent analysis of polarization with incident silicon beams. Finally, the most recent results on subthreshold antiproton production is presented. These latter results are several orders of magnitude more than expected and they point to some kind of coherent hadronic phenomena even at extremely low energies

  20. Relativistic Hydrodynamics for Heavy-Ion Collisions

    Science.gov (United States)

    Ollitrault, Jean-Yves

    2008-01-01

    Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…

  1. The Relativistic Heavy Ion Collider

    Science.gov (United States)

    Fischer, Wolfram

    The Relativistic Heavy Ion Collider (RHIC), shown in Fig. 1, was build to study the interactions of quarks and gluons at high energies [Harrison, Ludlam and Ozaki (2003)]. The theory of Quantum Chromodynamics (QCD) describes these interactions. One of the main goals for the RHIC experiments was the creation and study of the Quark-Gluon Plasma (QGP), which was expected to be formed after the collision of heavy ions at a temperature of approximately 2 trillion kelvin (or equivalently an energy of 150 MeV). The QGP is the substance which existed only a few microseconds after the Big Bang. The QGP was anticipated to be weakly interacting like a gas but turned out to be strongly interacting and more like a liquid. Among its unusual properties is its extremely low viscosity [Auerbach and Schlomo (2009)], which makes the QGP the substance closest to a perfect liquid known to date. The QGP is opaque to moderate energy quarks and gluons leading to a phenomenon called jet quenching, where of a jet and its recoil jet only one is observable and the other suppressed after traversing and interacting with the QGP [Jacak and Müller (2012)]...

  2. RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Friedlander, Erwin M.; Heckman, Harry H.

    1982-04-01

    Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.

  3. Viscous photons in relativistic heavy ion collisions

    CERN Document Server

    Dion, Maxime; Schenke, Bjoern; Young, Clint; Jeon, Sangyong; Gale, Charles

    2011-01-01

    Theoretical studies of the production of real photons in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are performed. The space-time evolution of the colliding system is modelled using MUSIC, a 3+1D relativistic hydrodynamic simulation. The inclusive spectrum and its azimuthal angular anisotropy are studied separately, and the relative contributions of the different photon sources are highlighted. It is shown that the photon v_2 coefficient is especially sensitive to the details of the microscopic dynamics like the equation of state, the ratio of shear viscosity over entropy density, eta/s, and to the morphology of the initial state.

  4. Viscous photons in relativistic heavy ion collisions

    Science.gov (United States)

    Dion, Maxime; Paquet, Jean-François; Schenke, Björn; Young, Clint; Jeon, Sangyong; Gale, Charles

    2011-12-01

    Theoretical studies of the production of real thermal photons in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are performed. The space-time evolution of the colliding system is modelled using music, a 3+1D relativistic hydrodynamic simulation, using both its ideal and viscous versions. The inclusive spectrum and its azimuthal angular anisotropy are studied separately, and the relative contributions of the different photon sources are highlighted. It is shown that the photon v2 coefficient is especially sensitive to the details of the microscopic dynamics like the equation of state, the ratio of shear viscosity over entropy density, η/s, and to the morphology of the initial state.

  5. Color screening in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    We calculate the color screening length in a non-equilibrated gluon gas formed by interacting minijets in relativistic heavy-ion collisions. We show that the screening length is too short at CERN LHC collider energy to permit the formation of independent flux-tubes or strings. The prediction for RHIC energies is somewhat ambiguous. (orig.)

  6. Diffraction radiation from relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Potylitsyna, N.A. E-mail: nata@interact.phtd.tpu.edu.ru

    2001-01-01

    In recent years, the relativistic heavy ion beams at new accelerator facilities are allowed to obtain some new interesting results (see, for instance, Datz et al., Phys. Rev. Lett. 79 (18) (1997) 3355; Ladyrin et al., Nucl. Instr. and Meth. A 404 (1998) 129). The problem of non-destructive heavy ion beam diagnostics at these accelerators is highly pressing. The authors of the papers (Rule et al., Proceedings of the Seventh Beam Instrumentation Workshop, Argonne IL, AIP Conference Proceedings, Vol. 390, NY, 1997; Castellano, Nucl. Instr. and Meth. A 394 (1997) 275) suggested to use diffraction radiation (DR) appearing when a charge moves close to a conducting surface (Bolotovskii and Voskresenskii, Sov. Phys. Usp. 9 (1966) 73) for non-destructive electron beam diagnostics. The DR characteristics are defined by both Lorentz-factor and the particle charge, and do not depend on its mass. The estimation of feasibility of using DR for relativistic ion beam diagnostics is undoubtedly interesting.

  7. Recent results on relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Munhoz, Marcelo [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Inst. de Fisica

    2013-07-01

    Full text: The study of relativistic heavy ion collisions is a very important tool in order to understand the strong interaction described by QCD. The formation of the Quark-Gluon Plasma and the study of its properties is a very challenging quest. The Large Hadron Collider (LHC) from CERN (European Organization for Nuclear Research) generates ultra-relativistic Pb + Pb collisions at the TeV scale inaugurating a new era for such studies. Three experiments, ATLAS, CMS and ALICE are able to measure the products of such collisions. In special, the ALICE experiment was designed specifically for the study of heavy ion collisions. In this presentation, I'll discuss the latest results that shed light in the QGP understanding. (author)

  8. Hydrodynamic approaches in relativistic heavy ion reactions

    Science.gov (United States)

    Derradi de Souza, R.; Koide, T.; Kodama, T.

    2016-01-01

    We review several facets of the hydrodynamic description of the relativistic heavy ion collisions, starting from the historical motivation to the present understandings of the observed collective aspects of experimental data, especially those of the most recent RHIC and LHC results. In this report, we particularly focus on the conceptual questions and the physical foundations of the validity of the hydrodynamic approach itself. We also discuss recent efforts to clarify some of the points in this direction, such as the various forms of derivations of relativistic hydrodynamics together with the limitations intrinsic to the traditional approaches, variational approaches, known analytic solutions for special cases, and several new theoretical developments. Throughout this review, we stress the role of course-graining procedure in the hydrodynamic description and discuss its relation to the physical observables through the analysis of a hydrodynamic mapping of a microscopic transport model. Several questions to be answered to clarify the physics of collective phenomena in the relativistic heavy ion collisions are pointed out.

  9. Relativistic Heavy Quark Spectrum On Anisotropic Lattices

    CERN Document Server

    Liao, X

    2003-01-01

    We report a fully relativistic quenched calculation of the heavy quark spectrum, including both charmonium and bottomonium, using anisotropic lattice QCD. We demonstrate that a fully relativistic treatment of a heavy quark system is well-suited to address the large systematic errors in non-relativistic calculations. In addition, the anisotropic lattice formulation is a very efficient framework for calculations requiring high temporal resolutions. A detailed excited charmonium spectrum is obtained, including both the exotic hybrids (with JPC = 1−+ , 0+−, 2+−) and orbitally excited mesons (with orbital angular momentum up to 3). Using three different lattice spacings (0.197, 0.131, and 0.092 fm), we perform a continuum extrapolation of the spectrum. The lowest lying exotic hybrid 1−+ lies at 4.428(41) GeV, slightly above the D**D (S + P wave) threshold of 4.287 GeV. Another two exotic hybrids 0+− and 2 +− are determined to be 4.70(17) GeV and 4.895(88)...

  10. Hydrodynamic Approaches in Relativistic Heavy Ion Reactions

    CERN Document Server

    de Souza, Rafael Derradi; Kodama, Takeshi

    2016-01-01

    We review several facets of the hydrodynamic description of the relativistic heavy ion collisions, starting from the historical motivation to the present understandings of the observed collective aspects of experimental data, especially those of the most recent RHIC and LHC results. In this report, we particularly focus on the conceptual questions and the physical foundations of the validity of the hydrodynamic approach itself. We also discuss recent efforts to clarify some of the points in this direction, such as the various forms of derivations of relativistic hydrodynamics together with the limitations intrinsic to the traditional approaches, variational approaches, known analytic solutions for special cases, and several new theoretical developments. Throughout this review, we stress the role of course-graining procedure in the hydrodynamic description and discuss its relation with the physical observables through the analysis of a hydrodynamic mapping of a microscopic transport model. Several questions to...

  11. RHIC and quark matter: proposal for a relativistic heavy ion collider at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    This document describes the Brookhaven National Laboratory Proposal for the construction of a Relativistic Heavy Ion Collider (RHIC). The construction of this facility represents the natural continuation of the laboratory's role as a center for nuclear and high-energy physics research and extends and uses the existing AGS, Tandem Van de Graaff and CBA facilities at BNL in a very cost effective manner. The Administration and Congress have approved a project which will provide a link between the Tandem Van de Graaf and the AGS. Completion of this project in 1986 will provide fixed target capabilities at the AGS for heavy ions of about 14 GeV/amu with masses up to approx. 30 (sulfur). The addition of an AGS booster would extend the mass range to the heaviest ions (A approx. 200, e.g., gold); its construction could start in 1986 and be completed in three years. These two new AGS experimental facilities can be combined with the proposed Relativistic Heavy Ion Collider to extend the energy range to 100 x 100 GeV/amu for the heaviest ions. BNL proposes to start construction of RHIC in FY 86 with completion in FY 90 at a total cost of 134 M$

  12. RHIC and quark matter: proposal for a relativistic heavy ion collider at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1984-08-01

    This document describes the Brookhaven National Laboratory Proposal for the construction of a Relativistic Heavy Ion Collider (RHIC). The construction of this facility represents the natural continuation of the laboratory's role as a center for nuclear and high-energy physics research and extends and uses the existing AGS, Tandem Van de Graaff and CBA facilities at BNL in a very cost effective manner. The Administration and Congress have approved a project which will provide a link between the Tandem Van de Graaf and the AGS. Completion of this project in 1986 will provide fixed target capabilities at the AGS for heavy ions of about 14 GeV/amu with masses up to approx. 30 (sulfur). The addition of an AGS booster would extend the mass range to the heaviest ions (A approx. 200, e.g., gold); its construction could start in 1986 and be completed in three years. These two new AGS experimental facilities can be combined with the proposed Relativistic Heavy Ion Collider to extend the energy range to 100 x 100 GeV/amu for the heaviest ions. BNL proposes to start construction of RHIC in FY 86 with completion in FY 90 at a total cost of 134 M$.

  13. Heavy ions: Report from Relativistic Heavy Ion Collider

    Indian Academy of Sciences (India)

    Sonia Kabana

    2012-10-01

    We review selected highlights from the experiments at the Relativistic Heavy Ion Collider (RHIC) exploring the QCD phase diagram. A wealth of new results appeared recently from RHIC due to major recent upgrades, like for example the $\\Upsilon$ suppression in central nucleus-nucleus collisions which has been discovered recently in both RHIC and LHC. Furthermore, we discuss RHIC results from the beam energy scan (BES) program aiming to search for a possible critical point and to map out the QCD phase diagram.

  14. Diomega production in relativistic heavy ion collisions

    OpenAIRE

    Pal, Subrata; Ko, C. M.; Zhang, Z. Y.

    2001-01-01

    Using a multiphase transport model, we study the production of a new strange dibaryon (\\Omega\\Omega)_{0+} in dense hadronic matter formed in relativistic heavy ion collisions. The (multi-)strange baryons (\\Xi and \\Omega) are produced by strangeness-exchange reactions between antikaons and hyperons in the pure hadronic phase. The rescattering between the omegas at midrapidity leads to a production probability of \\simeq 3x10^{-7} (\\Omega\\Omega)_{0+} per event at the RHIC energy of \\sqrt s=130A ...

  15. Proceedings of the Budapest workshop on relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    This volume is the Proceedings of the Budapest workshop on relativistic heavy ion collisions held in Budapest, 10-13 Aug, 1992. The topics include experimental heavy ion physics, Bose-Einstein correlations, intermittency, relativistic transport theory, Quark-Gluon Plasma rehadronization, astronuclear physics and cosmology. All contributions were indexed and abstracted. (author)

  16. Theoretical Concepts for Ultra-Relativistic Heavy Ion Collisions

    CERN Document Server

    McLerran, Larry

    2009-01-01

    Various forms of matter may be produced in ultra-relativistic heavy ion collisions. These are the Quark Gluon Plasma, the Color Glass Condensate, the Glasma and Quarkyonic Matter. A novel effect that may be associated with topological charge fluctuations is the Chiral Magnetic Effect. I explain these concepts and explain how they may be seen in ultra-relativistic heavy ion collisions.

  17. System size in relativistic heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    WANG Yang-Yang; ZHAO Lin-Jie; YUAN Zhong-Sheng; ZHANG Dan-Dan; FANG Wei; XU Ming-Mei

    2011-01-01

    System size is more than a geometrical quantity in relativistic heavy ion collisions; it is closely related to evolution process,i.e.a different system size corresponds to a different evolution process,and whether QGP is produced depends on the system size.We propose that the system size should be under the same level when comparing the measurements from different colliding nuclei.The equivalence of the peripheral collisions of Au-Au and the central collisions of smaller nuclei is studied using the Monte Carlo method.Comparing the transverse overlapping area of the colliding nuclei,the number of participant nucleons and the number of nucleon-nucleon binary collisions in various colliding nuclei,we give an estimate of the correspondence in system size.This is helpful in the experimental comparison of the measurements from different colliding nuclei.

  18. Conference on the Intersections of Particle and Nuclear Physics 2003 Relativistic Heavy Ion Parallel Session Summary

    CERN Document Server

    Nagle, J L

    2003-01-01

    The Relativistic Heavy Ion Collider (RHIC) came online in 2000, and the last three years have provided a wealth of new experimental data and theoretical work in this new energy frontier for nuclear physics. The transition from quarks and gluons bound into hadrons to a deconfined quark-gluon plasma is expected to occur at these energies, and the effort to understand the time evolution of these complex systems has been significantly advanced. The heavy ion parallel session talks from the Conference on the Intersections of Particle and Nuclear Physics (CIPANP) 2003 are posted at: http://www.phenix.bnl.gov/WWW/publish/nagle/CIPANP/. We provide a brief summary of these sessions here.

  19. Relativistic NJL Model with Light and Heavy Quarks

    OpenAIRE

    Mota, A. L.; Arriola, E. Ruiz

    2006-01-01

    We study the Nambu-Jona-Lasinio model with light and heavy quarks in a relativistic approach. We emphasize relevant regularization issues as well as the transition from light to heavy quarks. The approach of the electromagnetic meson form factor to the Isgur-Wise function in the heavy quark limit is also discussed.

  20. Gamma-ray spectroscopy with relativistic exotic heavy-ions

    Indian Academy of Sciences (India)

    Samit Mandal; J Gerl; H Geissel; K Hauschild; M Hellström; Z Janas; I Kojouharov; Y Kopatch; R C Lemmon; P Mayet; Z Podolyak; P H Regan; H Schaffner; C Schlegel; J Simpson; H J Wollersheim

    2001-07-01

    Feasibility of gamma-ray spectroscopy at relativistic energies with exotic heavy-ions and new generation of germanium detectors (segmented Clover) is discussed. An experiment with such detector array and radioactive is discussed.

  1. Study of relativistic heavy ion central collisions

    International Nuclear Information System (INIS)

    This thesis is devoted to the study of nuclear collisions between a target nucleus and a projectile nucleus, the latter having been accelerated at energies ranging from 100 to 2000 MeV (Mega-Electronvolts) per nucleon. The main goal of this field is the determination of nuclear matter equation of state at high densities and temperatures. This determination requires the study of central collisions only, that is collisions at small impact parameters. The detector ''Diogene'' used at the ''Saturne'' (Saclay, France) accelerator can measure simultaneously the momenta, masses and emission angles of all particles (pions, protons, deuterons ...) emitted in each collision. The pressure effects pre-dicted by the ''intra-nuclear cascade'' model are discussed. The pion (pi meson) production in relativistic heavy ion collisions is reviewed. Finally, we present the results of pion production measurements, using ''Diogene'', in collisions between alpha particles and carbon, copper, or lead target nuclei at 200, 400, 600 and 800 MeV per nucleon. The number of pions per collision is studied in relationship with the proton number. This can be explained in terms of compressional energy. The pion multiplicity distributions and the differential cross-sections are also presented

  2. String theory and relativistic heavy ion collisions

    Science.gov (United States)

    Friess, Joshua J.

    It has long been known that string theory describes not only quantum gravity, but also gauge theories with a high degree of supersymmetry. Said gauge theories also have a large number of colors in a regime with a large effective coupling constant that does not depend on energy scale. Supersymmetry is broken in nature, if it is present at all, however the gauge theory described by string theory shares many common features with QCD at temperatures above the quark deconfinement transition. It is generally though not entirely accepted that collisions of gold nuclei at the Relativistic Heavy Ion Collider (RHIC) produce a thermalized Quark-Gluon Plasma (QGP) at temperatures distinctly above the transition temperature as determined from lattice simulations. Hence, we might hope that a string theoretic description of gauge dynamics can elucidate some otherwise intractable physics of the strongly coupled plasma. Here we use string theory to calculate the outgoing energy flux from a RHIC process called "jet quenching", in which a high-momentum quark or gluon traverses a large distance in the QGP. Our setup is in the context of the highly supersymmetric string dual gauge theory, but we nevertheless find that the gross features of the resulting stress-energy tensor match reasonably well with experimental data. We will furthermore discuss the technology behind computations of the leading-order corrections to gauge theory observables that are uniquely string-induced, and we will describe a potential solution to string theory that could resolve a number of discrepancies between the traditional highly supersymmetric setup and QCD---in particular, a significant reduction in the amount of supersymmetry, and a finite effective coupling that is still greater than unity but does depend on energy scale.

  3. The Relativistic Heavy Ion Collider control system

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, T.S.; Barton, D.S.; Oerter, B.R.

    1997-12-01

    The Relativistic Heavy Ion Collider control system has been used in the commissioning of the AGS to RHIC transfer line and in the first RHIC sextant test. Much of the controls infrastructure for networks and links has been installed throughout the collider. All of the controls hardware modules needed to be built for early RHIC operations have been designed and tested. Many of these VME modules are already being used in normal AGS operations. Over 150 VME based front end computers and device controllers will be installed by the Summer of 1998 in order to be ready for Fall of 1998. A few features are being added to the front end computer core software. The bulk of the Accelerator Device Objects (ADOs) which are instantiated in the FECs, have been written and tested in the early commissioning. A configuration database has been designed. Generic control and display of ADO parameters via a spreadsheet like program on the console level computers was provided early on in the control system development. User interface tools that were developed for the AGS control system have been used in RHIC applications. Some of the basic operations programs, like alarm display and save/restore, that are used in the AGS operations have been or will be expanded to support RHIC operations. A model for application programs which involves a console level manager servicing ADOs have been verified with a few RHIC applications. More applications need to be written for the Fall of 1998 commissioning effort. A sequencer for automatic control of the fill is being written with the expectation that it will be useful in early commissioning.

  4. Bremsstrahlung Pair Production In Relativistic Heavy Ion Collision

    OpenAIRE

    Meier, H; Hencken, K.; Trautmann, D.; Baur, G.

    1997-01-01

    We calculate production of electron- and muon-pairs by the bremsstrahlung process in hadron collisions and compare it with the dominant two-photon process. Results for the total cross section are given for proton-proton and heavy-ion collisions at energies of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC).

  5. Collective Flow and Viscosity in Relativistic Heavy-Ion Collisions

    NARCIS (Netherlands)

    Heinz, U.; Snellings, R.J.M.

    2013-01-01

    We review collective flow, its anisotropies, and its event-to-event fluctuations in relativistic heavy-ion collisions, as well as the extraction of the specific shear viscosity of quark–gluon plasma from collective flow data collected in heavy-ion collision experiments at RHIC and the LHC. We emphas

  6. Quarkonia at finite temperature in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    Saumen Datta

    2015-05-01

    The behaviour of quarkonia in relativistic heavy-ion collisions is reviewed. After a detailed discussion of the current theoretical understanding of quarkonia in a static equilibriated plasma, we discuss quarkonia yield from the fireball created in ultrarelativistic heavy-ion collision experiments. We end with a brief discussion of the experimental results and outlook.

  7. Charged particle multiplicity in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    What follows is a brief overview of the E814 silicon multiplicity detector and some of the data taken with it during a June 89 heavy ion physics run at the BNL AGS. The beam was 14.6 GeV/c/u 28Si on targets of Pb, Cu, and Al. For the data presented below all of the target thicknesses were 1.2% of a Si interaction length. All of the data shown below are still in analysis and none are final

  8. Electromagnetic processes in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    A study of the processes generated by the electromagnetic interaction in relativistic nuclear, and atomic collisions is presented. Very strong electromagnetic fields for a very short time are present in distant collisions with no nuclear contact. Such fields can also lead to interesting effects, which are discussed here. (orig.)

  9. Lambda-Lambda Correlation in Relativistic Heavy Ion Collisions

    OpenAIRE

    Morita Kenji; Furumoto Takenori; Ohnishi Akira

    2015-01-01

    We investigate Λ − Λ correlation function in relativistic heavy ion collisions to extract their interaction. Using an expanding source model for heavy ion collisions, we disentangle effects of collective expansion and those of the interaction at low relative momenta. Then, we discuss the influence of the feed-down correction for Σ0 decay and indicate the possible existence of a residual correlation at high relative momenta. Consequently, the present STAR data suggest a weakly attractive inter...

  10. Soft electromagnetic radiations from relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Photons and dileptons have long been considered as excellent probes of quark-gluon plasma (QGP) expected to be formed in relativistic heavy ion collisions. To evaluate soft photons and dileptons from quark matter as well as soft photon approximation (SPA) is applied. The estimations of soft electromagnetic radiations that exists in the literature have certain discrepancies and efforts were made to correct them

  11. Collective flow in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    R S Bhalerao

    2003-11-01

    A brief introduction is given to the field of collective flow, currently being investigated experimentally at the Relativistic Heavy-Ion Collider, Brookhaven National Laboratory. It is followed by an outline of the work that I have been doing in this field, in collaboration with Nicolas Borghini and Jean-Yves Ollitrault.

  12. Relativistic corrections to the electromagnetic decays of heavy quarkonium states

    International Nuclear Information System (INIS)

    Expressions are presented which go beyond the usual non-relativistic approximation for the electromagnetic decay widths of vector and pseudoscalar mesons in the quark model. Numerical calculations within typical potential models for heavy quark-antiqurak systems show the corrections thus obtained to be substantial. Possible experimental implications for the psi and UPSILON families are discussed. (Auth.)

  13. Reconstruction of the Proton Source in Relativistic Heavy Ion Collisions

    OpenAIRE

    Polleri, Alberto; Mattiello, Raffaele; Mishustin, Igor; Bondorf, Jakob

    1999-01-01

    We describe a direct method to reconstruct the transverse proton source formed in a relativistic heavy ion collision, making use of experimentally measured proton and deuteron spectra and assuming that deuterons are formed via two-nucleon coalescence. We show that an ambiguity with respect to the source temperature still persists and we indicate a possible solution to the problem.

  14. Electromagnetic excitation of 136Xe in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    In the framework of the experimental program at the accelerator facilities SIS/ESR at the Society for Heavy Ion Research in Darmstadt a detector system for relativistic neutrons was developed, constructed, and applied in first experiments. An essential research aim is the study of collective states after electromagnetic excitation in relativistic heavy ion collisions. In peripheral collisions high-energy virtual photons are exchanged. This leads to the excitation of giant resonances, especially of the giant dipole and quadrupole resonance. An essential decay channel of giant resonances in heavy nuclei is the emission of neutrons, followed by the emission of γ radiation below the particle threshold. These decay channels were studied with the detector system developed by the LAND collaboration. A first experiment on the electromagnetic excitation was performed with a 136Xe beam at an energy of 700 MeV/u and Pb respectively C targets. (orig./HSI)

  15. FUTURE SCIENCE AT THE RELATIVISTIC HEAVY ION COLLIDER.

    Energy Technology Data Exchange (ETDEWEB)

    LUDLAM, T.

    2006-12-21

    QCD was developed in the 1970's as a theory of the strong interaction describing the confinement of quarks in hadrons. An early consequence of this picture was the realization that at sufficiently high temperature, or energy density, the confining forces are overcome by color screening effects, resulting in a transition from hadronic matter to a new state--later named the Quark Gluon Plasma--whose bulk dynamical properties are determined by the quark and gluon degrees of freedom, rather than those of confined hadrons. The suggestion that this phase transition in a fundamental theory of nature might occur in the hot, dense nuclear matter created in heavy ion collisions triggered a series of experimental searches during the past two decades at CERN and at BNL, with successively higher-energy nuclear collisions. This has culminated in the present RHIC program. In their first five years of operation, the RHIC experiments have identified a new form of thermalized matter formed in Au+Au collisions at energy densities more than 100 times that of a cold atomic nucleus. Measurements and comparison with relativistic hydrodynamic models indicate that the matter thermalizes in an unexpectedly short time ( < 1 fm/c) , has an energy density at least 15 times larger than needed for color deconfinement, has a temperature about 2 times the critical temperature of {approx}170 MeV predicted by lattice QCD, and appears to exhibit collective motion with ideal hydrodynamic properties--a ''perfect liquid'' that appears to flow with a near-zero viscosity to entropy ratio - lower than any previously observed fluid and perhaps close to a universal lower bound. There are also indications that the new form of matter directly involves quarks. Comparison of measured relative hadron abundances with very successful statistical models indicates that hadrons chemically decouple at a temperature of 160-170 MeV. There is evidence suggesting that this happens very close to the

  16. Hadron production in relativistic heavy ion interactions and the search for the quark-gluon plasma

    Energy Technology Data Exchange (ETDEWEB)

    Tannenbaum, M.J.

    1989-12-01

    The course starts with an introduction, from the experimentalist's point of view, of the challenge of measuring Relativistic Heavy Ion interactions. A review of some theoretical predictions for the expected signatures of the quark gluon plasma will be made, with a purpose to understand how they relate to quantities which may be experimentally measured. A short exposition of experimental techniques and details is given including charged particles in matter, momentum resolution, kinematics and Lorentz Transformations, calorimetry. Principles of particle identification including magnetic spectrometers, time of flight measurement. Illustrations using the E802 spectrometer and other measured results. Resolution smearing of spectra, and binning effects. Parent to daughter effects in decay, with {pi}{sup 0} {yields} {gamma} {gamma} as an example. The experimental situation from the known data in p -- p collisions and proton-nucleus reactions is reviewed and used as a basis for further discussions. The Cronin Effect'' and the Seagull Effect'' being two arcana worth noting. Then, selected experiments from the BNL and CERN heavy ion programs are discussed in detail. 118 refs., 45 figs.

  17. CMBE v05-Implementation of a toy-model for chaos analysis of relativistic nuclear collisions at the present BNL energies

    Science.gov (United States)

    Grossu, I. V.; Felea, D.; Jipa, Al.; Besliu, C.; Stan, E.; Ristea, O.; Ristea, C.; Calin, M.; Esanu, T.; Bordeianu, C.; Tuturas, N.

    2014-11-01

    In this paper we present a new version of Chaos Many-Body Engine (CMBE) Grossu et al. (2014) [1]. Inspired by the Mean Free Path concept, we implemented a new parameter, namely the “Mean Free Time”, which is defined as the mean time between one particle’s creation and its stimulated decay. This new parameter should be understood as an effect of the nuclear environment and, as opposed to the particle lifetime, it has the advantage of not being affected by the relativistic dilation. In [2] we presented a toy-model for chaos analysis of relativistic nuclear collisions at 4.5 A GeV/c (the SKM 200 collaboration). In this work, we extended our model to 200 A GeV (the maximum BNL energy). Catalogue identifier: AEGH_v5_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGH_v5_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Microsoft Public License (Ms-PL) No. of lines in distributed program, including test data, etc.: 638984 No. of bytes in distributed program, including test data, etc.: 15918340 Distribution format: tar.gz Programming language: Visual C# .Net 2010 Computer: PC Operating system: .Net Framework 4.0 running on MS Windows RAM: 128 MB Classification: 24.60.Lz, 05.45.a Catalogue identifier of previous version: AEGH_v4_0 Journal reference of previous version: Computer Physics Communications 185 (2014) 1339 Does the new version supersede the previous version?: Yes Nature of problem: Toy-model for relativistic nuclear collisions at present BNL energies. Solution method: Relativistic many-body OOP engine, including a reactions module. Implementation of the “Mean Free Time” parameter; Implementation of a new example of use for relativistic nuclear collisions at present BNL energies. Implementation of a new parameter, namely the “Mean Free Time”, defined as the mean time between one particle’s creation and its stimulated decay. The Mean Free Time should be understood as an

  18. Particle-production mechanism in relativistic heavy-ion collisions

    CERN Document Server

    Bush, B W; Brian W Bush

    1994-01-01

    We discuss the production of particles in relativistic heavy-ion collisions through the mechanism of massive bremsstrahlung, in which massive mesons are emitted during rapid nucleon acceleration. This mechanism is described within the framework of classical hadrodynamics for extended nucleons, corresponding to nucleons of finite size interacting with massive meson fields. This new theory provides a natural covariant microscopic approach to relativistic heavy-ion collisions that includes automatically spacetime nonlocality and retardation, nonequilibrium phenomena, interactions among all nucleons, and particle production. Inclusion of the finite nucleon size cures the difficulties with preacceleration and runaway solutions that have plagued the classical theory of self-interacting point particles. For the soft reactions that dominate nucleon-nucleon collisions, a significant fraction of the incident center-of-mass energy is radiated through massive bremsstrahlung. In the present version of the theory, this rad...

  19. Relativistic fluid dynamics in heavy ion collisions

    CERN Document Server

    Pu, Shi

    2011-01-01

    This dissertation is about the study of three important issues in the theory of relativistic fluid dynamics: the stability of dissipative fluid dynamics, the shear viscosity, and fluid dynamics with triangle anomaly.(1)The second order theory of fluid dynamics is necessary for causality. However the causality cannot be guaranteed for all parameters. The constraints for parameters are then given. We also point out that the causality and the stability are inter-correlated. It is found that a causal system must be stable, but an acausal system in the boost frame at high speed must be unstable. (2)The transport coefficients can be determined in kinetic theory. We will firstly discuss about derivation of the shear viscosity via variational method in the Boltzmann equation. Secondly, we will compute the shear viscosity via AdS/CFT duality in a Bjorken boost invariant fluid with radial flow. It is found that the ratio of the shear viscosity to entropy density is consistent with the work of Policastro, Son and Starin...

  20. BRAHMS collaboration results for relativistic heavy ion collisions

    Science.gov (United States)

    Arsene, I.

    2008-12-01

    In this work we review very briefly a few of the most important results obtained by the BRAHMS Collaboration on the properties of the collisions of heavy ions at relativistic energies. The discussion is general and aims to illustrate the most important achievements of our collaboration during the RHIC run period with short discussions and references to articles that treat the subjects in more detail.

  1. Azimuthal Correlation of Collective Motion in Relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    HUO Lei; ZHANG Wei-Ning; CHEN Xiang-Jun; TANG Gui-Xin; ZHANG Jing-Bo

    2001-01-01

    The out-of-plane squeeze-out effect in relativistic heavy ion collisions is used to estimate the reaction plane by performing a modified transverse momentum analysis. A technique for investigating the azimuthal correlation between the out-of-plane squeeze-out and directed in-plane flow is described. A clear signature of the azimuthal correlation is evidenced in the 600 A MeV Au + Au reaction from the quantum molecular dynamic model calculations.

  2. Rotating quark-gluon plasma in relativistic heavy ion collisions

    CERN Document Server

    Jiang, Yin; Liao, Jinfeng

    2016-01-01

    We study the rotational collective motion of the quark-gluon plasma in relativistic heavy ion collisions using the widely-adopted AMPT (A Multi-Phase Transport) model. The global angular momentum, the average vorticity carried by the quark-gluon plasma, and the locally defined vorticity fields are computed for Au+Au collisions, with detailed information of their time evolution, spatial distribution, as well as the dependence on beam energy and collision centrality.

  3. Lambda-proton correlations in relativistic heavy ion collisions

    OpenAIRE

    Wang, Fuqiang; Pratt, Scott

    1999-01-01

    The prospect of using lambda-proton correlations to extract source sizes in relativistic heavy ion collisions is investigated. It is found that the strong interaction induces a large peak in the correlation function that provides more sensitive source size measurements than two-proton correlations under some circumstances. The prospect of using lambda-proton correlations to measure the time lag between lambda and proton emissions is also studied.

  4. Lepton interferometry in relativistic heavy ion collisions - a case study

    OpenAIRE

    Alam, Jan-e; Mohanty, Bedangadas; Rahaman, A .; Sarkar, Sourav; Sinha, Bikash

    2004-01-01

    We propose intensity interferometry with identical lepton pairs as an efficient tool for the estimation of the source size of the expanding hot zone produced in relativistic heavy ion collisions. This can act as a complementary method to two photon interferometry. The correlation function of two electrons with the same helicity has been evaluated for RHIC energies. The thermal shift of the rho meson mass has negligible effects on the HBT radii.

  5. Deciphering Azimuthal Correlations in Relativistic Heavy-Ion Collisions

    OpenAIRE

    Cetner, Tomasz; Grebieszkow, Katarzyna; Mrowczynski, Stanislaw

    2010-01-01

    We discuss various sources of azimuthal correlations in relativistic heavy-ion collisions. The integral measure Phi is applied to quantify the correlations. We first consider separately the correlations caused by the elliptic flow, resonance decays, jets and transverse momentum conservation. An effect of randomly lost particles is also discussed. Using the PYTHIA and HIJING event generators we produce a sample of events which mimic experimental data. By means of kinematic cuts and particle's ...

  6. Heavy-light mesons in a relativistic model

    Science.gov (United States)

    Liu, Jing-Bin; Yang, Mao-Zhi

    2016-07-01

    We study the heavy-light mesons in a relativistic model, which is derived from the Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation to the heavy quark. The kernel we choose is based on scalar confinement and vector Coulomb potentials. The transverse interaction of the gluon exchange is also taken into account in this model. The spectra and wave functions of D, Ds, B, Bs meson states are obtained. The spectra are calculated up to the order of 1/m Q, and wave functions are treated to leading order. Supported by National Natural Science Foundation of China (11375088, 10975077, 10735080, 11125525)

  7. The relativistic heavy ion collider project at Brookhaven

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) facility will provide collision energies of 100 GeV/nucleon per beam for heavy ions as massive as gold. RHIC will use the existing Brookhaven AGS and Tandem Van de Graaff as injector. The new accelerator facility, which is a nuclear physics initiative, will utilize the existing facilities of the partially completed CBA project. This report discusses the physics motivation for such a facility, the status of the machine design, R and D work and preparations for experiments at RHIC

  8. Lambda-Lambda Correlation in Relativistic Heavy Ion Collisions

    Directory of Open Access Journals (Sweden)

    Morita Kenji

    2015-01-01

    Full Text Available We investigate Λ − Λ correlation function in relativistic heavy ion collisions to extract their interaction. Using an expanding source model for heavy ion collisions, we disentangle effects of collective expansion and those of the interaction at low relative momenta. Then, we discuss the influence of the feed-down correction for Σ0 decay and indicate the possible existence of a residual correlation at high relative momenta. Consequently, the present STAR data suggest a weakly attractive interaction for the ΛΛ pairs which is represented by the scattering length, 1/a0 < −0.8 fm−1.

  9. Beam loss mechanisms in relativistic heavy-ion colliders

    CERN Document Server

    Bruce, Roderik; Gilardoni, S; Wallén, E

    2009-01-01

    The Large Hadron Collider (LHC), the largest particle accelerator ever built, is presently under commissioning at the European Organization for Nuclear Research (CERN). It will collide beams of protons, and later Pb82+ ions, at ultrarelativistic energies. Because of its unprecedented energy, the operation of the LHC with heavy ions will present beam physics challenges not encountered in previous colliders. Beam loss processes that are harmless in the presently largest operational heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, risk to cause quenches of superconducting magnets in the LHC. Interactions between colliding beams of ultrarelativistic heavy ions, or between beam ions and collimators, give rise to nuclear fragmentation. The resulting isotopes could have a charge-to-mass ratio different from the main beam and therefore follow dispersive orbits until they are lost. Depending on the machine conditions and the ion species, these losses could occur in loca...

  10. Transport models for relativistic heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider

    Indian Academy of Sciences (India)

    Subrata Pal

    2015-05-01

    We review the transport models that are widely used to study the properties of the quark-gluon plasma formed in relativistic heavy-ion collisions at RHIC and LHC. We show that transport model analysis of two important and complementary observables, the anisotropic flow of bulk hadrons and suppression of hadron yields at high transverse momentum, provide exciting new information on the properties of the plasma formed.

  11. The Mesozoic Era of relativistic heavy ion physics and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Harris, J.W.

    1994-03-01

    In order to understand how matter 15 billion years ago in the form of quarks, gluons and leptons at a temperature of 2 {times} 10{sup 12} {degrees}K evolved to become today`s Universe, the goal of relativistic and ultra-relativistic heavy ion physics is to understand the equation of state of nuclear, hadronic and partonic matter. This quest is of cross-disciplinary interest. The phase transition from partonic matter to hadronic matter tens of micro-seconds after the beginning of the universe is of interest to cosmology. Fluctuations during this phase transition would influence nucleosynthesis and the understanding of baryonic inhomogeneities in the universe. The nuclear matter equation of state, which describes the incompressibility of nuclear matter, governs neutron star stability. It determines the possible existence of strange quark matter stars and the dynamics of supernova expansion in astrophysics. The existence of collective nuclear phenomena in nuclear physics is also determined by the nuclear equation of state. In relativistic heavy ion collisions collective nuclear flow has been observed and is being studied extensively to obtain a better understanding of the incompressibility of nuclear matter. In high energy nuclear and particle physics, production and excitations of hadronic final states have been studied in detail and are important to an overall understanding of the equation of state of nuclear matter at finite temperature. The possibility in ultra-relativistic heavy ion collisions to create and study highly excited hadronic and partonic degrees of freedom provides a unique opportunity for understanding the behavior of nuclear, hadronic and partonic matter. Study of the QCD vacuum, of particular interest in particle physics, would provide a better understanding of symmetry-breaking mechanisms and the origins of the masses of the various quarks and particles.

  12. CERN achievements in relativistic heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Bruno Giuseppe Eugenio

    2015-01-01

    Full Text Available Twenty years after a Letter of Intent by the GSI and LBL groups for the “Study of particle production and target fragmentation in central 20Ne on Pb reactions, at 12 GeV per nucleon energy of the CERN PS external beam" [1], based on the results found by the NA45/CERES, NA49, NA50, and WA97/NA57 experiments at the SPS, CERN announced compelling evidence for the formation of a new state of matter in heavyion collisions at CERN-SPS energies [2]. Some of the experiments were indeed the 2nd or 3rd generation successors of the apparatuses originally proposed by the GSI-LBL collaboration. Actually, the CERN ion program initiated at the SPS with the acceleration of oxygen ions at 60 and 200 GeV/nucleon only in 1986, and continued with sulphur ions at 200 GeV/nucleon up to 1993. The rest is history: lead-ion beams at 160 GeV/nucleon became available at the SPS in 1994; the LHC accelerated and collided lead beams at a center of mass energy per nucleon pair √sNN = 2.76 TeV in 2010. Heavy ion physics is definitely in the future program of CERN: ALICE will operate a major upgrade of its detectors during the second long shutdown of the LHC, in 2018-2019, and the associated physics program will span the third and fourth LHC runs, till late 2020s.

  13. An Experimental Review on Elliptic Flow of Strange and Multistrange Hadrons in Relativistic Heavy Ion Collisions

    Directory of Open Access Journals (Sweden)

    Shusu Shi

    2016-01-01

    Full Text Available Strange hadrons, especially multistrange hadrons, are good probes for the early partonic stage of heavy ion collisions due to their small hadronic cross sections. In this paper, I give a brief review on the elliptic flow measurements of strange and multistrange hadrons in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC and Large Hadron Collider (LHC.

  14. Ultra-relativistic heavy ions and the CBA

    International Nuclear Information System (INIS)

    The study of ultra-relativistic heavy ions at an accelerator such as the CBA provides a unique glimpse of matter as it may have appeared in the early universe. This hot dense matter very probably appears as a quark-gluon plasma which expands and cools into hadronic matter. The CBA would provide data at the very highest energies, and produce matter at the highest energy densities. The possibility of using a cyclotron to inject very heavy ions into the AGS and then into the CBA would also allow the production of quark-gluon matter at higher energy densities than would light ions, and would make the matter in a larger volume where surface effects are minimized. At the highest energies with very heavy ions, there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. Some of the possibilities are discussed

  15. Ultra-relativistic heavy ions and cosmic rays

    International Nuclear Information System (INIS)

    The collisions of ultra-relativistic heavy ions, E/sub /N/ greater than or equal to 1 TeV/nucleon are most interesting, since, at these energies, matter is produced at sufficiently high energy density that a quark-gluon plasma has a good chance to form. Very heavy ions are also most interesting since the matter forms in a larger volume than for light ions, and the matter is at a somewhat higher energy density. At very high energies with very heavy ions there is great flexibility in the experimental signals which might be studied, as well as the nature of the matter which is produced. The fragmentation region and central region provide different environments where a plasma might form. The former is baryon rich while the central region is high temperature with low baryon number density and is not accessible except at very high energies

  16. Proceedings of RIKEN BNL Research Center Workshop: Brookhaven Summer Program on Quarkonium Production in Elementary and Heavy Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Dumitru, A.; Lourenco, C.; Petreczky, P.; Qiu, J., Ruan, L.

    2011-08-03

    Understanding the structure of the hadron is of fundamental importance in subatomic physics. Production of heavy quarkonia is arguably one of the most fascinating subjects in strong interaction physics. It offers unique perspectives into the formation of QCD bound states. Heavy quarkonia are among the most studied particles both theoretically and experimentally. They have been, and continue to be, the focus of measurements in all high energy colliders around the world. Because of their distinct multiple mass scales, heavy quarkonia were suggested as a probe of the hot quark-gluon matter produced in heavy-ion collisions; and their production has been one of the main subjects of the experimental heavy-ion programs at the SPS and RHIC. However, since the discovery of J/psi at Brookhaven National Laboratory and SLAC National Accelerator Laboratory over 36 years ago, theorists still have not been able to fully understand the production mechanism of heavy quarkonia, although major progresses have been made in recent years. With this in mind, a two-week program on quarkonium production was organized at BNL on June 6-17, 2011. Many new experimental data from LHC and from RHIC were presented during the program, including results from the LHC heavy ion run. To analyze and correctly interpret these measurements, and in order to quantify properties of the hot matter produced in heavy-ion collisions, it is necessary to improve our theoretical understanding of quarkonium production. Therefore, a wide range of theoretical aspects on the production mechanism in the vacuum as well as in cold nuclear and hot quark-gluon medium were discussed during the program from the controlled calculations in QCD and its effective theories such as NRQCD to various models, and to the first principle lattice calculation. The scientific program was divided into three major scientific parts: basic production mechanism for heavy quarkonium in vacuum or in high energy elementary collisions; the

  17. Electromagnetic Heavy Lepton Pair Production in Relativistic Heavy-Ion Collisions

    OpenAIRE

    Sengul, M. Y.; Guclu, M. C.; Mercan, O.; Karakus, N. G.

    2015-01-01

    We calculate the cross sections of electromagnetic productions of muon and tauon pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement [1] indicates that the neutrons are differently distributed from the protons therefore this affects the cross section of the heavy lepton pair productio...

  18. Transport properties of the fluid produced at Relativistic Heavy-Ion Collider

    Indian Academy of Sciences (India)

    Rajeev S Bhalerao

    2010-08-01

    It is by now well known that the relativistic heavy-ion collisions at RHIC, BNL have produced a strongly interacting fluid with remarkable properties, among them the lowest ever observed ratio of the coefficient of shear viscosity to entropy density. Arguments based on ideas from the string theory, in particular the AdS/CFT correspondence, led to the conjecture – now known to be violated – that there is an absolute lower limit 1/4 on the value of this ratio. Causal viscous hydrodynamics calculations together with the RHIC data have put an upper limit on this ratio, a small multiple of 1/4, in the relevant temperature regime. Less well-determined is the ratio of the coefficient of bulk viscosity to entropy density. These transport coefficients have also been studied non-perturbatively in the lattice QCD framework, and perturbatively in the limit of high-temperature QCD. Another interesting transport coefficient is the coefficient of diffusion which is also being studied in this context. In this paper some of these recent developments are reviewed and then the opportunities presented by the anticipated LHC data are discussed, for the general nuclear physics audience.

  19. Fractal clusters and intermittency in relativistic heavy ion collisions

    CERN Document Server

    Antoniou, Nikos G; Diakonos, F K

    2000-01-01

    We investigate the formation of particle clusters (pions) associated with the chiral QCD phase transition in thermodynamic equilibrium. The geometry of these clusters at the critical point (T=T/sub c/) turns out to be fractal reflecting the self similar structure of the density fluctuations of the produced pions. The fractal dimension of the "critical" clusters is related to the critical exponents characterizing the phase transition. We examine the possibility to observe such pion clusters in relativistic heavy ion collisions. A Monte Carlo simulation of the critical system in 3D is performed leading to a typical set of "critical" events. Factorial moment analysis of the rapidity and transverse momentum distribution for these events shows a characteristic intermittency pattern. Mini-jet like structures arise in a azimuth angle rapidity lego plot. These features allow for a unique identification of the class of "critical events" in an event by event analysis in current and future experiments with relativistic ...

  20. Modelling early stages of relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Ruggieri M.

    2016-01-01

    Full Text Available In this study we model early time dynamics of relativistic heavy ion collisions by an initial color-electric field which then decays to a plasma by the Schwinger mechanism. The dynamics of the many particles system produced by the decay is described by relativistic kinetic theory, taking into account the backreaction on the color field by solving self-consistently the kinetic and the field equations. Our main results concern isotropization and thermalization for a 1+1D expanding geometry. In case of small η/s (η/s ≲ 0.3 we find τisotropization ≈ 0.8 fm/c and τthermalization ≈ 1 fm/c in agreement with the common lore of hydrodynamics.

  1. Production of spectator hypermatter in relativistic heavy-ion collisions

    CERN Document Server

    Botvina, A S; Steinheimer, J; Bleicher, M; Mishustin, I N

    2011-01-01

    We study the formation of large hyper-fragments in relativistic heavy-ion collisions within two transport models, DCM and UrQMD. Our goal is to explore a new mechanism for the formation of strange nuclear systems via capture of hyperons by relatively cold spectator matter produced in semi-peripheral collisions. We investigate basic characteristics of the produced hyper-spectators and evaluate the production probabilities of multi-strange systems. Advantages of the proposed mechanisms over an alternative coalescence mechanism are analysed. We also discuss how such systems can be detected taking into account the background of free hyperons. This investigation is important for the development of new experimental methods for producing hyper-nuclei in peripheral relativistic nucleus-nucleus collisions, which are now underway at GSI and are planned for the future FAIR and NICA facilities.

  2. Spectra of heavy-light mesons in a relativistic model

    CERN Document Server

    Liu, Jing-Bin

    2016-01-01

    The spectra and wave functions of heavy-light mesons are calculated within a relativistic quark model, which is derived from the instantaneous Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation on the heavy quark. The kernel we choose is based on scalar confining and vector Coulomb potentials. The Hamiltonian for heavy-light quark-antiquark system is calculated up to order $1/m_Q^2$. The results are in good agreement with available experimental data except for the masses of the anomalous $D_{s0}^*(2317)$ and $D_{s1}(2460)$ states. The newly observed charmed meson states can be accommodated successfully in the relativistic model and their assignments are presented, the $D_{sJ}^*(2860)$ can be interpreted as the $|1^{3/2}D_1\\rangle$ and $|1^{5/2}D_3\\rangle$ states being the $J^P=1^-$ and $3^-$ members of the 1D family in our model.

  3. Workshop on Quark-Gluon Plasma and Relativistic Heavy Ions

    CERN Document Server

    Lombardo, Maria Paola; Nardi, Marzia; GISELDA 2002; QGP 2002

    2002-01-01

    This book offers the unique possibility of tackling the problem of hadronic deconfinement from different perspectives. After general introductions to the physical issues, from both the theoretical and the experimental point of view, the book presents the most recent expertise on field theory approaches to the QCD phase diagram, many-body techniques and applications, the dynamics of phase transitions, and phenomenological analysis of relativistic heavy ion collisions. One of the major goals of this book is to promote interchange among those fields of research, which have traditionally been cult

  4. Beyond the thermal model in relativistic heavy-ion collisions

    Science.gov (United States)

    Wolschin, Georg

    2016-08-01

    Deviations from thermal distribution functions of produced particles in relativistic heavy-ion collisions are discussed as indicators for nonequilibrium processes. The focus is on rapidity distributions of produced charged hadrons as functions of collision energy and centrality, which are used to infer the fraction of particles produced from a central fireball as compared with that from the fragmentation sources that are out of equilibrium with the rest of the system. Overall thermal equilibrium would only be reached for large times t →∞ .

  5. Searching for $\\Xi_{cc}^+$ in Relativistic Heavy Ion Collisions

    CERN Document Server

    Zhao, Jiaxin; Zhuang, Pengfei

    2016-01-01

    We study the doubly charmed baryon $\\Xi_{cc}^+$ in high energy nuclear collisions. We solve the three-body Schroedinger equation with relativistic correction and calculate the $\\Xi_{cc}^+$ yield and transverse momentum distribution via coalescence mechanism. For $\\Xi_{cc}^+$ production in central Pb+Pb collisions at LHC energy, the yield is extremely enhanced, and the production cross section per binary collision is one order of magnitude larger than that in p+p collisions. This indicates that, it is most probable to discover $\\Xi_{cc}^+$ in heavy ion collisions and its discovery can be considered as a probe of the quark-luon plasma formation.

  6. Beyond the thermal model in relativistic heavy-ion collisions

    CERN Document Server

    Wolschin, Georg

    2016-01-01

    Deviations from thermal distribution functions of produced particles in relativistic heavy-ion collisions are discussed as indicators for nonequilibrium processes. The focus is on rapidity distributions of produced charged hadrons as functions of collision energy and centrality which are used to infer the fraction of produced particles from a central fireball as compared to the one from the fragmentation sources that are out of equilibrium with the rest of the system. Overall thermal equilibrium would only be reached for large times t -> infinity.

  7. Bremsstrahlung from relativistic bare heavy ions: Nuclear and electronic contributions in amorphous and crystalline materials

    DEFF Research Database (Denmark)

    Jensen, Tue Vissing; Sørensen, Allan Hvidkjær

    2013-01-01

    A charged particle emits bremsstrahlung while traversing matter. We calculate the radiation cross section for bare heavy ions penetrating amorphous materials and single crystals at highly relativistic energies. The main component originates in scattering of the virtual photons of screened target...... in a pronounced directional dependence of the energy loss of bare heavy ions at extreme relativistic energies....

  8. Proceedings of the Workshop on relativistic heavy ion physics at present and future accelerators

    International Nuclear Information System (INIS)

    This volume contains the Proceedings of the Budapest Workshop on relativistic heavy ion physics at present and future accelerators. The topics includes experimental heavy ion physics, particle phenomenology, Bose-Einstein correlations, relativistic transport theory, quark-gluon plasma rehadronization, astronuclear physics, leptonpair production and intermittency. All contributions were indexed separately for the INIS database. (G.P.)

  9. Formulation of relativistic dissipative fluid dynamics and its applications in heavy-ion collisions

    OpenAIRE

    Jaiswal, Amaresh

    2014-01-01

    Relativistic fluid dynamics finds application in astrophysics, cosmology and the physics of high-energy heavy-ion collisions. In this thesis, we present our work on the formulation of relativistic dissipative fluid dynamics within the framework of relativistic kinetic theory. We employ the second law of thermodynamics as well as the relativistic Boltzmann equation to obtain the dissipative evolution equations. We present a new derivation of the dissipative hydrodynamic equations using the sec...

  10. Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)

    Energy Technology Data Exchange (ETDEWEB)

    Karsch,F.; Kharzeev, D.; Molnar, K.; Petreczky, P.; Teaney, D.

    2008-04-21

    The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also transport coefficients from RHIC data. There has been a lot of progress with solving relativistic viscous hydrodynamics. There are already large uncertainties in ideal hydrodynamics calculations, e.g., uncertainties associated with initial conditions, freezeout, and the simplified equations of state typically utilized. One of the most sensitive observables to the equation of state is the baryon momentum anisotropy, which is also affected by freezeout assumptions. Up-to-date results from lattice quantum chromodynamics on the transition temperature and equation of state with realistic quark masses are currently available. However, these have not yet been incorporated into the hydrodynamic calculations. Therefore, the RBRC workshop 'Hydrodynamics in Heavy Ion Collisions and QCD Equation of State' aimed at getting a better understanding of the theoretical frameworks for dissipation and near-equilibrium dynamics in heavy-ion collisions. The topics discussed during the workshop included techniques to solve the dynamical equations and examine the role of initial conditions and decoupling, as well as the role of the equation of state and transport coefficients in current simulations.

  11. Heavy Quarkonium Dissociation Cross Sections in Relativistic Heavy-Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    C.-Y. Wong; Eric Swanson; Ted Barnes

    2001-12-01

    Many of the hadron-hadron cross sections required for the study of the dynamics of matter produced in relativistic heavy-ion collisions can be calculated using the quark-interchange model. Here we evaluate the low-energy dissociation cross sections of J/{psi}, {psi}', {chi}, {Upsilon}, and {Upsilon}' in collision with {pi}, {rho}, and K, which are important for the interpretation of heavy-quarkonium suppression as a signature for the quark gluon plasma. These comover dissociation processes also contribute to heavy-quarkonium suppression, and must be understood and incorporated in simulations of heavy-ion collisions before QGP formation can be established through this signature.

  12. Stopping of relativistic heavy ions in various media

    Science.gov (United States)

    Waddington, C. J.; Fixsen, D. J.; Crawford, H. J.; Lindstrom, P. J.; Heckman, H. H.

    1986-01-01

    The residual ranges of (900 + or - 3)-MeV/amu gold nuclei accelerated at the Lawrence Berkeley Laboratory Bevalac have been measured in several different media. The energy of the beam of nuclei was measured directly using a new time-of-flight system. The ranges were measured by absorption in linear wedges of polyethylene, carbon, aluminum, copper, tin, and lead and in circular wedges of polystyrene, aluminum, and gold, and by total absorption in nuclear emulsion. The measured ranges were significantly different from those calculated from the best available theoretical estimates of the energy loss of highly charged nuclei. It is concluded that at present energy losses and residual ranges of relativistic heavy ions in an arbitrary medium cannot be predicted with better than an approximately 2 percent accuracy.

  13. Conceptual design of the Relativistic Heavy Ion Collider [RHIC

    International Nuclear Information System (INIS)

    In August 1984 Brookhaven National Laboratory submitted a proposal for the construction of a Relativistic Heavy Ion Collider (RHIC) to the US Department of Energy. A Conceptual Design Report for the RHIC facility was completed in May 1986 after detailed reviews of the machine design, and of the requirements of the physics research program. Since that time an extensive R ampersand D program has been initiated and considerable work has been carried out to refine the design and specification of the major accelerator components, as well as the needs for research detectors, and to prepare the project for construction. This document is an update of the Conceptual Design Report, incorporating the results of work carried out since the beginning of Fiscal Year 1987 when a formal R ampersand D program for the RHIC project funded by DOE was initiated

  14. Causal Viscous Hydrodynamics for Relativistic Heavy Ion Collisions

    CERN Document Server

    Song, Huichao

    2009-01-01

    The viscosity of the QGP is a presently hotly debated subject. Since its computation from first principles is difficult, it is desirable to try to extract it from experimental data. Viscous hydrodynamics provides a tool that can attack this problem and which may work in regions where ideal hydrodynamics begins to fail. This thesis focuses on viscous hydrodynamics for relativistic heavy ion collisions. We first review the 2nd order viscous equations obtained from different approaches, and then report on the work of the Ohio State University group on setting up the equations for causal viscous hydrodynamics in 2+1 dimensions and solving them numerically for central and noncentral Cu+Cu and Au+Au collisions at RHIC energies and above. We discuss shear and bulk viscous effects on the hydrodynamic evolution of entropy density, temperature, collective flow, and flow anisotropies, and on the hadron multiplicity, single particle spectra and elliptic flow. Viscous entropy production and its influence on the centrality...

  15. Monitoring relativistic heavy ion beams at the Bevalac

    International Nuclear Information System (INIS)

    Beam fluence in high intensity proton and electron accelerators is usually measured with Secondary Emission Monitors (SEM) calibrated by an activation method. These were no such activation measurements available for relativistic heavy ion beams. Secondary electron production and energy loss of a charged particle in passing through material are a result of Coulomb interaction between the projectile field and electrons in the material. Therefore range measurements and secondary emission yield should follow the same functional relationship of velocity and charge as given by the Bethe-Bloch equation. A substantial amount of data on range in water for various ions has been collected at the Bevalac Biomedical facility. Using the same calculations that convert measured proton ranges to ion ranges and comparing the calculated values to measured values, provides an indirect way to verify the validity of the SEM calibration. The results of these measurements are discussed in this paper

  16. Beam-beam observations in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  17. Lambda-Lambda interaction from relativistic heavy-ion collisions

    CERN Document Server

    Morita, Kenji; Ohnishi, Akira

    2014-01-01

    We investigate the two-particle intensity correlation function of $\\Lambda$ in relativistic heavy-ion collisions. We find that the behavior of the $\\Lambda\\Lambda$ correlation function at small relative momenta is fairly sensitive to the interaction potential and collective flows. By comparing the results of different source functions and potentials, we explore the effect of intrinsic collective motions on the correlation function. We find that the recent STAR data gives a strong constraint on the scattering length and effective range of $\\Lambda\\Lambda$ interaction as, $-1.8~\\mathrm{fm}^{-1} < 1/a_0 < -0.8~\\mathrm{fm}^{-1}$ and $3.5~\\mathrm{fm} < r_\\mathrm{eff} < 7~\\mathrm{fm}$, respectively. Implication for the signal of existence of $H$-dibaryon is discussed. Comparison with the scattering parameters obtained from the double $\\Lambda$ hypernucleus may reveal in-medium effects in the $\\Lambda\\Lambda$ interaction.

  18. Mass spectra of doubly heavy baryons in the relativistic quark model

    OpenAIRE

    Ebert, D; Faustov, R. N.; Galkin, V. O.; Martynenko, A. P.

    2002-01-01

    Mass spectra of baryons consisting of two heavy (b or c) and one light quarks are calculated in the framework of the relativistic quark model. The light quark-heavy diquark structure of the baryon is assumed. Under this assumption the ground and excited states of both the diquark and quark-diquark bound system are considered. The quark-diquark potential is constructed. The light quark is treated completely relativistically, while the expansion in the inverse heavy quark mass is used revealing...

  19. Phenomenology of Heavy Flavors in Ultrarelativistic Heavy-Ion Collisions

    CERN Document Server

    Isayev, A A

    2010-01-01

    Some recent experimental results obtained in collisions of heavy nuclei ($\\sqrt{s}=200$ GeV) at BNL Relativistic Heavy-Ion Collider (RHIC) are discussed. The probes of dense matter created in heavy-ion collision by quarkonia, $D$ and $B$ mesons containing heavy charm and beauty quarks are considered. The centrality, rapidity and transverse momentum dependences of the nuclear modification factor and elliptic flow coefficient are presented and their possible theoretical interpretation is provided.

  20. Heavy flavours in ultra-relativistic heavy ions collisions; Les saveurs lourdes dans les collisions d'ions lourds ultra-relativistes

    Energy Technology Data Exchange (ETDEWEB)

    Rosnet, Ph

    2008-01-15

    The ultra-relativistic collisions of heavy ions are the today's only means to tackle in laboratory conditions the phase diagram in quantum chromodynamics and the strong interaction. The most recent theoretical studies predict a phase transition between the cold nuclear matter (a hadronic gas) and a plasma of quarks and gluons. Heavy flavour can characterize the nuclear matter produced in a heavy ion collision as well as its spatial-temporal evolution. Their study can be made through their decay into muons. The first part of this work presents the issue of ultra-relativistic heavy ion collisions and the role of heavy flavours. In the second part the author reviews the results of experiments performed at RHIC and particularly presents the analysis of the mass spectrum of dimuons in the Phenix experiment. The third part describes the muon trigger system of the Alice experiment at CERN and the expected performances for the study of di-muons.

  1. Two views on the Bjorken scenario for ultra-relativistic heavy-ion collisions

    CERN Multimedia

    Maire, Antonin

    2011-01-01

    The sketch describes the Bjorken scenario foreseen for the collision of ultra-relativistic heavy-ions, leading to the creation of strongly-interacting hot and dense deconfined matter, the so-called Quark-Gluon Plasma (QGP).

  2. Ultra-relativistic heavy-ion physics with AFTER@LHC

    CERN Document Server

    Rakotozafindrabe, A; Brodsky, S J; Chambert, V; Didelez, J P; Genolini, B; Ferreiro, E G; Fleuret, F; Hadjidakis, C; Lansberg, J P; Rosier, P; Schienbein, I; Scomparin, E; Uggerhoj, U I

    2012-01-01

    We outline the opportunities for ultra-relativistic heavy-ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal.

  3. An inversion-asymmetric source function for HBT analysis in relativistic heavy ion collisions

    OpenAIRE

    Lianshou, Liu; Shusu, Shi; Jiaxin, Du

    2006-01-01

    The inversion-asymmetry of the emission source in relativistic heavy ion collision under the Bertsch-Pratt convention is discussed and explicitly exhibited by a Monte Carlo model. The Gaussian source function popularly used in the HBT analysis of relativistic heavy ion collisions is invalid in this case. An inversion-asymmetric source function is suggested. A method for extracting the inversion-asymmetry degree of the source together with the source size from experimental data is proposed.

  4. Electromagnetic heavy-lepton pair production in relativistic heavy-ion collisions

    Science.gov (United States)

    Şengül, M. Y.; Güçlü, M. C.; Mercan, Ö.; Karakuş, N. G.

    2016-08-01

    We calculate the cross sections of electromagnetic productions of muon- and tauon-pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement (Abrahamyan et al., Phys Rev Lett 108:112502, 2012) indicates that the neutrons are differently distributed from the protons; therefore this affects the cross section of the heavy-lepton pair production. In order to see the effects of the neutron distributions in the nucleus, we used analytical expression of the Fourier transforms of the Wood-Saxon distribution. Cross section calculations show that the Wood-Saxon distribution function is more sensitive to the parameter R compared to the parameter a.

  5. Electromagnetic Heavy Lepton Pair Production in Relativistic Heavy-Ion Collisions

    CERN Document Server

    Sengul, M Y; Mercan, O; Karakus, N G

    2015-01-01

    We calculate the cross sections of electromagnetic productions of muon and tauon pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement [1] indicates that the neutrons are differently distributed from the protons therefore this affects the cross section of the heavy lepton pair production. In order to see the effects of the neutron distributions in the nucleus, we used analytical expression of the Fourier transforms of the Wood-Saxon distribution. Cross section calculations show that Wood-Saxon distribution function is more sensitive to the parameter R compare to the parameter a.

  6. Conceptual design of the Relativistic Heavy Ion Collider: RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Samios, Nicholas P.

    1986-05-01

    The complete Relativistic Heavy Ion Collider (RHIC) facility will be a complex set of accelerators and beam transfer equipment connecting them. A significant portion of the total facility either exists or is under construction. Two existing Tandem Van de Graaff accelerators will serve for the initial ion acceleration. Ions with a charge of -1 would be accelerated from ground to +15 MV potential, pass through a stripping foil, and accelerate back to ground potential, where they would pass through a second stripping foil. From there the ions will traverse a long transfer line to the AGS tunnel and be injected into the Booster accelerator. The Booster accelerates the ion bunch, and then the ions pass through one more stripper and then enter the Alternating Gradient Synchrotron (AGS), where they are accelerated to the top AGS energy and transferred to the collider. Bending and focusing of ion beams is to be achieved by superconducting magnets. The physics goals behind the RHIC are enumerated, particularly as regards the study of quark matter and the characteristics of high energy nucleus-nucleus collisions. The design of the collider and all its components is described, including the injector, the lattice, magnet system, cryogenic and vacuum systems, beam transfer, injection, and dump, rf system, and beam instrumentation and control system. Also given are cost estimates, construction schedules, and a management plan. (LEW)

  7. The study of hadron dynamics in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    In this thesis, pion emission patterns were studied in two reaction systems Ar + Ca and Au + Au at 1 GeV/u, with the aim to improve the understanding of the pion production in relativistic heavy ion collisions. The study of the high energy tail of the π0-momentum spectrum was regarded as promising because of its sensitivity to compression since it did not appear in small reaction systems. Experiments were performed with TAPS together with the Forward Wall of the FoPi-collaboration at GSI. The combined measurement of charged particle multiplicities in the Forward Wall and the particles entering TAPS enabled an exclusive study of the pion production. TAPS was tested in separate experiments and its capabilities were demonstrated by measuring different reaction products, like photons, charged particles and neutrons. The data analysis involved new methods to treat the background contamination below the invariant mass peak of the π0-meson due to the geometry of the detector and to perform particle identification in a high particle multiplicity environment. (orig.)

  8. Conceptual design of the Relativistic Heavy Ion Collider: RHIC

    International Nuclear Information System (INIS)

    The complete Relativistic Heavy Ion Collider (RHIC) facility will be a complex set of accelerators and beam transfer equipment connecting them. A significant portion of the total facility either exists or is under construction. Two existing Tandem Van de Graaff accelerators will serve for the initial ion acceleration. Ions with a charge of -1 would be accelerated from ground to +15 MV potential, pass through a stripping foil, and accelerate back to ground potential, where they would pass through a second stripping foil. From there the ions will traverse a long transfer line to the AGS tunnel and be injected into the Booster accelerator. The Booster accelerates the ion bunch, and then the ions pass through one more stripper and then enter the Alternating Gradient Synchrotron (AGS), where they are accelerated to the top AGS energy and transferred to the collider. Bending and focusing of ion beams is to be achieved by superconducting magnets. The physics goals behind the RHIC are enumerated, particularly as regards the study of quark matter and the characteristics of high energy nucleus-nucleus collisions. The design of the collider and all its components is described, including the injector, the lattice, magnet system, cryogenic and vacuum systems, beam transfer, injection, and dump, rf system, and beam instrumentation and control system. Also given are cost estimates, construction schedules, and a management plan

  9. The Crystal Collimation System Of The Relativistic Heavy Ion Collider

    CERN Document Server

    Fliller, R P

    2004-01-01

    Crystal Channeling occurs when an ion enters a crystal with a small angle with respect to the crystal planes. The electrostatic interaction between the incoming ion and the lattice causes the ion to follow the crystal planes. By mechanically bending a crystal, it is possible to use a crystal to deflect ions. One novel use of a bent crystal is to use it to channel beam halo particles into a downstream collimator. By deflecting the halo particles into a collimator with a crystal it may be possible to improve the collimation efficiency as compared to a conventional two stage collimation system. A bent crystal was installed in the counterclockwise ring of the Relativistic Heavy Ion Collider (RHIC) prior to the FY2001 run to be used as the first stage of a two stage collimation system. We present a model and simulations to the predict crystal channeling efficiency. The simulations and model predict a channeling efficiency between 59% and 74% depending on the choice of optics. Attempts to reduce backgrounds in RHIC...

  10. INFN what next ultra-relativistic heavy-ion collisions

    CERN Document Server

    Dainese, A.; Usai, G.; Antonioli, P.; Arnaldi, R.; Beraudo, A.; Bruna, E.; Bruno, G.E.; Bufalino, S.; Di Nezza, P.; Lombardo, M.P.; Nania, R.; Noferini, F.; Oppedisano, C.; Piano, S.; Prino, F.; Rossi, A.; Agnello, M.; Alberico, W.M.; Alessandro, B.; Alici, A.; Andronico, G.; Antinori, F.; Arcelli, S.; Badala, A.; Barbano, A.M.; Barbera, R.; Barile, F.; Basile, M.; Becattini, F.; Bedda, C.; Bellini, F.; Beole, S.; Bianchi, L.; Bianchin, C.; Bonati, C.; Bossu, F.; Botta, E.; Caffarri, D.; Camerini, P.; Carnesecchi, F.; Casula, E.; Cerello, P.; Cicalo, C.; Cifarelli, M.L.; Cindolo, F.; Colamaria, F.; Colella, D.; Colocci, M.; Corrales Morales, Y.; Cortese, P.; De Caro, A.; De Cataldo, G.; De Falco, A.; De Gruttola, D.; D'Elia, M.; De Marco, N.; De Pasquale, S.; Di Bari, D.; Elia, D.; Fantoni, A.; Feliciello, A.; Ferretti, A.; Festanti, A.; Fionda, F.; Fiorenza, G.; Fragiacomo, E.; Fronze, G.G.; Girard, M. Fusco; Gagliardi, M.; Gallio, M.; Garg, K.; Giubellino, P.; Greco, V.; Grossi, E.; Guerzoni, B.; Hatzifotiadou, D.; Incani, E.; Innocenti, G.M.; Jacazio, N.; Das, S. Kumar; La Rocca, P.; Lea, R.; Leardini, L.; Leoncino, M.; Lunardon, M.; Luparello, G.; Mantovani Sarti, V.; Manzari, V.; Marchisone, M.; Margagliotti, G.V.; Masera, M.; Masoni, A.; Mastroserio, A.; Mazzilli, M.; Mazzoni, M.A.; Meninno, E.; Mesiti, M.; Milano, L.; Moretto, S.; Muccifora, V.; Nappi, E.; Nardi, M.; Nicassio, M.; Pagano, P.; Pappalardo, G.S.; Pastore, C.; Paul, B.; Petta, C.; Pinazza, O.; Plumari, S.; Preghenella, R.; Puccio, M.; Puddu, G.; Ramello, L.; Ratti, C.; Ravasenga, I.; Riggi, F.; Ronchetti, F.; Rucci, A.; Ruggieri, M.; Rui, R.; Sakai, S.; Scapparone, E.; Scardina, F.; Scarlassara, F.; Scioli, G.; Siddhanta, S.; Sitta, M.; Soramel, F.; Suljic, M.; Terrevoli, C.; Trogolo, S.; Trombetta, G.; Turrisi, R.; Vercellin, E.; Vino, G.; Virgili, T.; Volpe, G.; Williams, M.C.S.; Zampolli, C.

    2016-01-01

    This document was prepared by the community that is active in Italy, within INFN (Istituto Nazionale di Fisica Nucleare), in the field of ultra-relativistic heavy-ion collisions. The experimental study of the phase diagram of strongly-interacting matter and of the Quark-Gluon Plasma (QGP) deconfined state will proceed, in the next 10-15 years, along two directions: the high-energy regime at RHIC and at the LHC, and the low-energy regime at FAIR, NICA, SPS and RHIC. The Italian community is strongly involved in the present and future programme of the ALICE experiment, the upgrade of which will open, in the 2020s, a new phase of high-precision characterisation of the QGP properties at the LHC. As a complement of this main activity, there is a growing interest in a possible future experiment at the SPS, which would target the search for the onset of deconfinement using dimuon measurements. On a longer timescale, the community looks with interest at the ongoing studies and discussions on a possible fixed-target p...

  11. Pion correlations in relativistic heavy ion collisions at Heavy Ion Spectrometer Systems (HISS)

    International Nuclear Information System (INIS)

    This thesis contains the setup, analysis and results of experiment E684H ''Multi-Pion Correlations in Relativistic Heavy Ion Collisions''. The goals of the original proposal were: (1) To initiate the use of the HISS facility in the study of central Relativistic Heavy Ion Collisions (RHIC). (2) To perform a second generation experiment for the detailed study of the pion source in RHIC. The first generation experiments, implied by the second goal above, refer to pion correlation studies which the Riverside group had performed at the LBL streamer chamber. The major advantage offered by moving the pion correlation studies to HISS is that, being an electronic detector system, as opposed to the Streamer Chamber which is a visual detector, one can greatly increase the statistics for a study of this sort. An additional advantage is that once one has written the necessary detector and physics analysis code to do a particular type of study, the study may be extended to investigate the systematics, with much less effort and in a relatively short time. This paper discusses the Physics motivation for this experiment, the experimental setup and detectors used, the pion correlation analysis, the results, and the conclusions possible future directions for pion studies at HISS. If one is not interested in all the details of the experiment, I believe that by reading the sections on intensity interferometry, the section the fitting of the correlation function and the systematic corrections applied, and the results section, one will get a fairly complete synopsis of the experiment

  12. Open heavy flavor and other hard probes in ultra-relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    In this thesis hard probes are studied in the partonic transport model BAMPS (Boltzmann Approach to MultiParton Scatterings). Employing Monte Carlo techniques, this model describes the 3+1 dimensional evolution of the quark gluon plasma phase in ultra-relativistic heavy-ion collisions by propagating all particles in space and time and carrying out their collisions according to the Boltzmann equation. Since hard probes are produced in hard processes with a large momentum transfer, the value of the running coupling is small and their interactions should be describable within perturbative QCD (pQCD). This work focuses on open heavy flavor, but also addresses the suppression of light parton jets, in particular to highlight differences due to the mass. For light partons, radiative processes are the dominant contribution to their energy loss. For heavy quarks, we show that also binary interactions with a running coupling and an improved Debye screening matched to hard-thermal-loop calculations play an important role. Furthermore, the impact of the mass in radiative interactions, prominently named the dead cone effect, and the interplay with the Landau-Pomeranchuk-Migdal (LPM) effect are studied in great detail. Since the transport model BAMPS has access to all medium properties and the space time information of heavy quarks, it is the ideal tool to study the dissociation and regeneration of J/ψ mesons, which is also investigated in this thesis.

  13. An experimental review on elliptic flow of strange and multi-strange hadrons in relativistic heavy ion collisions

    CERN Document Server

    Shi, Shusu

    2016-01-01

    Strange hadrons, especially multi-strange hadrons are good probes for the early partonic stage of heavy ion collisions due to their small hadronic cross sections. In this paper, I give a brief review on the elliptic flow measurements of strange and multi-strange hadrons in relativistic heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC).

  14. Bremsstrahlung from Electrons and Positrons in Peripheral Relativistic Heavy Ion Collisions

    OpenAIRE

    Hencken, Kai; Trautmann, Dirk; Baur, Gerhard

    1999-01-01

    We study the spectrum of the bremsstrahlung photons coming from the electrons and positrons, which are produced in the strong electromagnetic fields present in peripheral relativistic heavy ion collisions. We compare different approaches, making use of the exact pair production cross section in heavy ion collisions as well as the double equivalent photon approximation.

  15. Deuteron Photodissociation in Ultraperipheral Relativistic Heavy-Ion on Deuteron Collisions

    OpenAIRE

    Klein, Spencer; Vogt, Ramona

    2003-01-01

    In ultraperipheral relativistic deuteron on heavy-ion collisions, a photon emitted from the heavy nucleus may dissociate the deuterium ion. We find deuterium breakup cross sections of 1.38 barns for deuterium-gold collisions at a center of mass energy of 200 GeV per nucleon, as studied at the Relativistic Heavy Ion Collider, and 2.49 barns for deuterium-lead collisions at a center of mass energy of 6.2 TeV, as proposed for the Large Hadron Collider. This cross section includes an energy-indep...

  16. Measurements of phi meson production in relativistic heavy-ion collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    STAR Coll

    2009-06-16

    We present results for the measurement of {phi} meson production via its charged kaon decay channel {phi} {yields} K{sup +}K{sup -} in Au + Au collisions at {radical}s{sub NN} = 62.4, 130, and 200 GeV, and in p + p and d + Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y| < 0.5) {phi} meson transverse momentum (p{sub T}) spectra in central Au + Au collisions are found to be well described by a single exponential distribution. On the other hand, the p{sub T} spectra from p + p, d + Au and peripheral Au + Au collisions show power-law tails at intermediate and high p{sub T} and are described better by Levy distributions. The constant {phi}/K{sup -} yield ratio vs beam species, collision centrality and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for {phi} production at RHIC. The {Omega}/{phi} yield ratio as a function of p{sub T} is consistent with a model based on the recombination of thermal s quarks up to p{sub T} {approx} 4 GeV/c, but disagrees at higher transverse momenta. The measured nuclear modification factor, R{sub dAu}, for the {phi} meson increases above unity at intermediate p{sub T}, similar to that for pions and protons, while R{sub AA} is suppressed due to the energy loss effect in central Au + Au collisions. Number of constituent quark scaling of both R{sub cp} and v{sub 2} for the {phi} meson with respect to other hadrons in Au + Au collisions at {radical}s{sub NN} = 200 GeV at intermediate p{sub T} is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate p{sub T} region at RHIC.

  17. BNL 56 MHz HOM damper prototype fabrication at JLAB

    Energy Technology Data Exchange (ETDEWEB)

    Huque, N.; McIntyre, G.; Daly, E. F.; Clemens, W.; Wu, Q.; Seberg, S.; Bellavia, S.

    2015-05-03

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider’s (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  18. BNL 56 MHz HOM Damper Prototype Fabrication at JLab

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Naeem A. [Jefferson Lab., Newport News, VA (United States); Daly, Edward F. [Jefferson Lab., Newport News, VA (United States); Clemens, William A. [Jefferson Lab., Newport News, VA (United States); McIntyre, Gary T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Qiong [Brookhaven National Lab. (BNL), Upton, NY (United States); Seberg, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Bellavia, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-01

    A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

  19. K-Vacancy Production in the Collision of Highly Charged Relativistic Ions With Heavy Atoms

    OpenAIRE

    Khabibullaev, P. K.

    2000-01-01

    A general expression for the cross section of the inelastic collision of relativistic highly charged ion with heavy (relativistic) atoms is obtained using the generalized eikonal approximation. In the ultrarelativistic limit, the obtained formula coincides with a known exact one. As an application of the obtained result, probability and cross section of the K-vacany production in the U92+ - U91+ collision are calculated.

  20. Elliptic Flow and Jet Quenching of a Parton System after Relativistic Heavy Ion Collision

    CERN Document Server

    Shin, Ghi R

    2007-01-01

    We obtain the initial phase space distribution after relativistic heavy ion collision by the CGC shattering method incorporating the uncertainty principle and solve the semi-classical Boltzmann equation which includes the gluon radiation processes. We present as a function of time the attenuation rate of high $p_T$ partons, which have transverse momenta over 6 $GeV/c$, in the medium which is formed after relativistic heavy ion collision. We calculate the elliptic flow as a function of an impact parameter, time and transverse momentum and also present the polar anisotropy, which gives the initial condition for color filamentation.

  1. Proceedings of the third workshop on experiments and detectors for a relativistic heavy ion collider (RHIC)

    International Nuclear Information System (INIS)

    This report contains papers on the following topics: the RHIC Project; summary of the working group on calorimetry; J//Psi/ measurements in heavy ion collisions at CERN; QCD jets at RHIC; tracking and particle identification; a 4π tracking spectrometer for RHIC; Bose-Einstein measurements at RHIC in light of new data; summary of working group on read-out electronics; data acquisition for RHIC; summary of the working group on detector simulation; B-physics at RHIC; and CP violation revisited at BNL, B-physics at RHIC

  2. Highlights from BNL and RHIC 2015

    CERN Document Server

    Tannenbaum, M J

    2016-01-01

    Highlights of news from Brookhaven National Laboratory (BNL) and results from the Relativistic Heavy Ion Collider (RHIC) in the period July 2014-June 2015 are presented. The news this year was mostly very positive. The major event at BNL was the startup and dedication of the new NSLS II, "the World's brightest Synchrotron Light Source". The operation of RHIC was outstanding with a polarized p+p run at $\\sqrt{s}=200$ GeV with integrated luminosity that exceeded the sum of all previous p+p integrated luminosity at this $\\sqrt{s}$. For the first time at RHIC asymmetric p+Au and p+Al runs were made but the p+Al run caused damage in the PHENIX forward detectors from quenches that were inadequately shielded for this first p+A run. This was also the 10th anniversary of the 2005 announcement of the Perfect Liquid Quark Gluon Plasma at RHIC and a review is presented of the discoveries leading to this claim. A new result on net-charge fluctuations (with no particle identification) from PHENIX based on previous scans ov...

  3. Charge state and energy loss of relativistic heavy ions in matter

    International Nuclear Information System (INIS)

    Relativistic heavy-ion collisions of few-electron projectiles ranging from argon up to uranium have been investigated in solid and gaseous media. Electron-loss and electron-capture cross sections, charge-state distributions, as well as energy loss and energy deposition have been measured and are compared with theoretical predictions. Especially fully-ionized heavy projectiles represent a unique possibility to test atomic-collision theories. (orig.)

  4. Formulation of relativistic dissipative fluid dynamics and its applications in heavy-ion collisions

    CERN Document Server

    Jaiswal, Amaresh

    2014-01-01

    Relativistic fluid dynamics finds application in astrophysics, cosmology and the physics of high-energy heavy-ion collisions. In this thesis, we present our work on the formulation of relativistic dissipative fluid dynamics within the framework of relativistic kinetic theory. We employ the second law of thermodynamics as well as the relativistic Boltzmann equation to obtain the dissipative evolution equations. We present a new derivation of the dissipative hydrodynamic equations using the second law of thermodynamics wherein all the second-order transport coefficients get determined uniquely within a single theoretical framework. An alternate derivation of the dissipative equations which does not make use of the two major approximations/assumptions namely, Grad's 14-moment approximation and second moment of Boltzmann equation, inherent in the Israel-Stewart theory, is also presented. Moreover, by solving the Boltzmann equation iteratively in a Chapman-Enskog like expansion, we have derived the form of second-...

  5. Low Energy Nuclear Structure from Ultra-relativistic Heavy-Light Ion collisions

    CERN Document Server

    Arriola, Enrique Ruiz

    2014-01-01

    The search for specific signals in ultra-relativistic heavy-light ion collisions addressing intrinsic geometric features of nuclei may open a new window to low energy nuclear structure. We discuss specifically the phenomenon of {\\alpha}-clustering in $^{12}$C when colliding with $^{208}$Pb at almost the speed of light.

  6. Towards relativistic heavy ion collisions by small steps towards the stars

    International Nuclear Information System (INIS)

    A review lecture is given on current attempts to search for the exotic processes occurring in relativistic heavy ion collisions. From peripheral collisions the discussion proceeds to central collisions and lastly the search for the exotic, in which the tools developed for the study of peripheral and central collisions are used. 200 references

  7. Towards relativistic heavy ion collisions by small steps towards the stars. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D.K.

    1979-03-01

    A review lecture is given on current attempts to search for the exotic processes occurring in relativistic heavy ion collisions. From peripheral collisions the discussion proceeds to central collisions and lastly the search for the exotic, in which the tools developed for the study of peripheral and central collisions are used. 200 references. (JFP)

  8. Remark on statistical model fits to particle ratios in relativistic heavy ion collisions

    OpenAIRE

    Becattini, F.

    2007-01-01

    In order to determine the chemical freeze-out parameters of the hadron-emitting source in relativistic heavy ion collisions some studies in literature perform fits by using as data input a subsample of ratios calculated out of experimentally measured hadron yields instead of yields themselves. We show that this is a statistically incorrect method fit, implying a bias in the extracted parameters.

  9. Heavy ion beam lifetimes at relativistic and ultrarelativistic colliders

    CERN Document Server

    Norbury, J W; Norbury, John W.; Waldsmith, Marsha L.

    1998-01-01

    The effects of higher order corrections in ultra-relativistic nuclear collisions are considered. It is found that higher order contributions are small at low energy, large at intermediate energy and small again at very high energy. An explanation for this effect is given. This means that the Weizsacker-Williams formula is a good approximation to use in calculating cross sections and beam lifetimes at energies relevant to RHIC and LHC.

  10. Hydrodynamic Evolution of Spherical Fireball in Relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    MIAO Hong; MA Zhong-Biao; GAO Chong-Shou

    2002-01-01

    Evolution process can be calculated from the relativistic hydrodynamic equation with certain estimatedinitial conditions about a single spherical fireball here. So one can estimate a kind of initial condition qualitatively witha possible energy density about ε0 ≈ 1.9 GeV/fm3, and to fit the experimental data at thermal freeze-out based on thisprocess. The evolution from a cylindrical fireball is discussed simply.

  11. Hydrodynamic Evolution of Spherical Fireball in Relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    MIAOHong; GAOChong-Shou; 等

    2002-01-01

    Evolution process can be calculated from the relativistic hydrodynamic equation with certain estimated initial conditions about a single spherical fireball here.So one can estimate a kind of initial condition qualitatively with a possible energy density about ε0≈1.9 GeV/fm3,and to fit the experimental data at thermal freeze-out based on this process.The evolution from a cylindrical fireball is discussed simply.

  12. Status of chemical equilibrium in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    J Cleymans

    2003-04-01

    Recent work on chemical equilibrium in heavy-ion collisions is reviewed. The energy dependence of thermal parameters is discussed. The centrality dependence of thermal parameters at SPS energies is presented.

  13. Coulex-multipolarimetry with relativistic heavy-ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, C., E-mail: stahl@ikp.tu-darmstadt.de [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Pietralla, N. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Rainovski, G. [Faculty of Physics, St. Kliment Ohridski University of Sofia, 1164 Sofia (Bulgaria); Reese, M. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2015-01-11

    We present a method suitable to measure E2/M1 multipole mixing ratios of nuclear ground-state transitions by comparison of relativistic Coulomb-excitation cross-sections at different ion velocities. The observation of the Coulomb-excitation at different ion velocities can be performed with high-resolution γ-ray detectors in one single experiment by using two targets mounted at a few centimeters distance along the beam axis. Excitation in either of the targets is distinguished by different observed Doppler-shifts.

  14. Proceedings of RIKEN BNL Research Center Workshop: Thermal Photons and Dileptons in Heavy-Ion Collisions. Volume 119

    Energy Technology Data Exchange (ETDEWEB)

    David, G. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Rapp, R. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Ruan, L. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Yee, H-U. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2014-09-11

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan and the U. S. Department of Energy’s Office of Science. The RBRC is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has theory, lattice gauge computing and experimental components. It is presently exploring the possibility of an astrophysics component being added to the program. The primary theme for this workshop related to sharing the latest experimental and theoretical developments in area of low transverse momentum (pT) dielectron and photons. All the presentations given at the workshop are included in this proceedings, primarily as PowerPoint presentations.

  15. The Unified Hydrodynamics and the Pseudorapidity Distributions in Heavy Ion Collisions at BNL-RHIC and CERN-LHC Energies

    Directory of Open Access Journals (Sweden)

    Z. J. Jiang

    2015-01-01

    Full Text Available The charged particles produced in nucleus-nucleus collisions are divided into two parts. One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand according to unified hydrodynamics and freezes out into charged particles from a space-like hypersurface with a fixed proper time of τFO. The leading particles are conventionally taken as the particles which inherit the quantum numbers of colliding nucleons and carry off most of incident energy. The rapidity distributions of the charged particles from these two parts are formulated analytically, and a comparison is made between the theoretical results and the experimental measurements performed in Au-Au and Pb-Pb collisions at the respective BNL-RHIC and CERN-LHC energies. The theoretical results are well consistent with experimental data.

  16. Production of parapositronium and orthpositronium at relativistic heavy ion colliders

    CERN Document Server

    Kotkin, G L; Schiller, A; Serbo, V G

    1999-01-01

    We consider the ortho-- and parapositronium production in the process $AA \\to AA+$ Ps where A is a nucleus with the charge number Z. The inclusive cross section and the energy distribution of the relativistic Ps are calculated which are of primary interest from the experimental point of view. The accuracy of the corresponding cross sections is given by omitting terms $\\sim (Z\\alpha )^2/L^2$ for the para--Ps and $\\sim (Z\\alpha)^2/L$ for the ortho--Ps production where $L=\\ln{\\gamma^2} \\approx 9$ and 16 for the RHIC and the LHC. Within this accuracy the multiphoton (Coulomb) corrections are taken into account. We show that the RHIC and the LHC will be Ps factories with a productions rate of about $10^5 \\div 10^8$ relativistic Ps per day. The fraction of the ortho--Ps is expected to be of the same order as that of the para--Ps for Au--Au and Pb--Pb collisions.

  17. Intranuclear cascade description of relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    A microscopic theory of heavy ion reactions based on the intranuclear cascade model is briefly discussed in an attempt to study the compression of nuclear matter. Double differential cross sections of 20Ne + 238U are shown as functions of impact parameter and bombarding energy for energies between 100 and 900 MeV/nucleon

  18. Experimental status of the AGS Relativistic Heavy Ion Program

    International Nuclear Information System (INIS)

    The universal motivation for colliding large nuclei at relativistic energies is the expectation that a small volume of the primordial quark soup, generally referred to as the Quark-Gluon Plasma (QGP), can be created and studied. The QGP is formed via a phase transition caused by either the extreme baryon densities and/or the extreme temperatures achieved in the overlap zone of the two colliding nuclei. Experiments at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS) using a beam of Si nuclei at 14.6 GeV per nucleon on various nuclear targets have been completed. These same experiments are now actively searching for signatures of QGP formation using a beam of Au nuclei at 11.7 GeV per nucleon. This paper briefly summarizes some of the key results from the Si beam program and the current status of the experimental Au beam program at the AGS

  19. Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

    Directory of Open Access Journals (Sweden)

    Ashwini Kumar

    2013-01-01

    Full Text Available The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.

  20. Hidden beauty and charm of relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    The goal of the SPS, RHIC, and LHC heavy-ion programs is to validate the existence and study the properties of the quark-gluon plasma (QGP), a phase of strongly - interacting matter at high energy density where quarks and gluons are no longer bound within hadrons. The quarkonia states (J/ψ and γ) have been among the most popular tools since their suppression was proposed as a signal of QGP formation. This is thought to be a direct effect of deconfinement, when the binding potential between the constituents of a quarkonium state, a heavy quark and its antiquark, is screened by the colour charges of the surrounding light quarks and gluons. This feebly bound quarkonia state then can be broken up by the gluon collisions

  1. What have we learned from relativistic heavy-ion collider?

    Indian Academy of Sciences (India)

    Larry McLerran

    2003-04-01

    In this talk, I present what I believe we have learned from the recent RHIC heavy ion experiments. The goal of these experiments is to make and study matter at very high energy densities, greater than an order of magnitude larger than that of nuclear matter. Have we made such matter? What have we learned about the properties of this matter? What do we hope and expect to learn in the future?

  2. Ionization of helium in relativistic heavy-ion collisions

    OpenAIRE

    Barna, Imre Ferenc

    2002-01-01

    The coupled-channel method is used to calculate single-, and double-ionisation cross sections for helium collisions with heavy ions. For highly charged and slow projectiles where the ratio of the projectile charge divided by the projectile velocity is in the magnitude of unity, non-perturbative methods must be used for proper description of the physical process. As basis functions Slater-like orbitals and regular Coulomb wave packages were taken. The Coulomb wave packages give a satisfacto...

  3. Free energy droplet formation in ultra-relativistic heavy-ion collision

    International Nuclear Information System (INIS)

    In ultra-relativistic heavy-ion collisions, quantum chromodynamics (QCD) predicts the phase transition from hadronic phase to the quark-gluon plasma phase. The lattice QCD calculations suggest the phase transition is of first order at a critical temperature around T ≈ 170 MeV. Such phase transition form a new state of matter, called the quark-gluon plasma (QGP). The fact is that the order of phase transitions are still unknown. In ultra-relativistic heavy-ion collisions, free energy droplet formation provide a unique opportunity as one of the promising experimental signature of the quark-gluon plasma. Thus, if transition is a first order then it may proceed with a supercooling quark gluon plasma followed by a nucleation and growth of droplet with the release of latent heat as the transition progress

  4. Initial Temperature and Extent of Chemical Equilibration of Partons in Relativistic Collision of Heavy Nuclei

    CERN Document Server

    Srivastava, Dinesh K; Mustafa, Munshi G

    2016-01-01

    We emphasize that a knowledge of energy and entropy densities of quark gluon plasma - a thermalized de-confined matter, formed in relativistic heavy ion collisions fixes the formation temperature and the product of gluon fugacity and formation time uniquely, {\\em provided} we know the relative fugacities of quarks and gluons. This also provides that a smaller formation time would imply larger fugacities for partons. Next we explore the limits of chemical equilibration of partons during the initial stages in relativistic collision of heavy nuclei. The experimentally measured rapidity densities of transverse energy and charged particle multiplicity at RHIC and LHC energies are used to estimate the energy and number densities with the assumption of formation of a thermally equilibrated quark gluon plasma which may be chemically equilibrated to the same or differing extents for quarks and gluons. The estimates are found to be very sensitive to the correction factor used for the Bj\\"{o}rken energy density for iden...

  5. Energy dependence of resonance production in relativistic heavy ion collisions

    CERN Document Server

    Shao, Feng-lan; Wang, Rui-qin; Zhang, Mao-sheng

    2016-01-01

    The production of hadronic resonances $K^{*}(892)$, $\\phi(1020)$, $\\Sigma^{*}(1385)$, and $\\Xi^{*}(1530)$ in central AA collisions at $\\sqrt{s_{NN}}=$ 17.3, 200, and 2760 GeV are systematically studied. The direct production of these resonances at system hadronization are described by the quark combination model and the effects of hadron multiple-scattering stage are dealt with by a ultra-relativistic quantum molecular dynamics model (UrQMD). We study the contribution of these two production sources to final observation and compare the final spectra with the available experimental data. The $p_T$ spectra of $K^{*}(892)$ calculated directly by quark combination model are explicitly higher than the data at low $p_T \\lesssim 1.5$ GeV and taking into account the modification of rescattering effects the resulting final spectra well agree with the data at all three collision energies. The rescattering effect on $\\phi(1020)$ production is weak and including it can slightly improve our description at low $p_T$ on the...

  6. Charge separation with fluctuating domains in relativistic heavy-ion collisions

    OpenAIRE

    Shou, Qi-Ye; Ma, Guo-Liang; Ma, Yu-Gang

    2014-01-01

    Charge separation induced by the chiral magnetic effect suggested that some ${\\cal P}$- or ${\\cal CP}$-odd metastable domains could be produced in a QCD vacuum in the early stage of relativistic heavy-ion collisions. Based on a multi-phase transport model, our results suggest that a domain-based scenario with final state interactions can describe the solenoidal tracker at RHIC detector (STAR) measurements of both same- and opposite-charge azimuthal angle correlations, $$, in Au+Au collisions ...

  7. Calculation of Higher Order Effects in Electron-Positron Pair Production in Relativistic Heavy Ion Collisions

    OpenAIRE

    Hencken, Kai; Trautmann, Dirk; Baur, Gerhard

    1998-01-01

    We present a calculation of higher order effects for the impact parameter dependent probability for single and multiple electron-positron pairs in (peripheral) relativistic heavy ion collisions. Also total cross sections are given for SPS and RHIC energies. We make use of the expression derived recently by several groups where the summation of all higher orders can be done analytically in the high energy limit. An astonishing result is that the cross section, that is, integrating over all imp...

  8. Anisotropy of low energy direct photons in relativistic heavy ion collisions

    Science.gov (United States)

    Koide, T.; Kodama, T.

    2016-09-01

    Using the Wigner function approach for electromagnetic radiation fields, we investigate the behavior of low energy photons radiated by the deceleration processes of two colliding nuclei in relativistic heavy ion collisions. The angular distribution reveals information of the initial geometric configurations, which is reflected in the anisotropic parameter v 2, with an increasing v 2 as energy decreases. This behavior is qualitatively different to the v 2 from the hadrons produced in the collisions.

  9. Two-Photon Interactions with Nuclear Breakup in Relativistic Heavy Ion Collisions

    OpenAIRE

    Baltz, Anthony J.; Gorbunov, Yuri; Klein, Spencer R.; Nystrand, Joakim

    2009-01-01

    Highly charged relativistic heavy ions have high cross-sections for two-photon interactions. The photon flux is high enough that two-photon interactions may be accompanied by additional photonuclear interactions. Except for the shared impact parameter, these interactions are independent. Additional interactions like mutual Coulomb excitation are of experimental interest, since the neutrons from the nuclear dissociation provide a simple, relatively unbiased trigger. We calculate the cross sect...

  10. The canonical effect in statistical models for relativistic heavy ion collisions

    OpenAIRE

    Keranen, A.; Becattini, F.

    2001-01-01

    Enforcing exact conservation laws instead of average ones in statistical thermal models for relativistic heavy ion reactions gives raise to so called canonical effect, which can be used to explain some enhancement effects when going from elementary (e.g. pp) or small (pA) systems towards large AA systems. We review the recently developed method for computation of canonical statistical thermodynamics, and give an insight when this is needed in analysis of experimental data.

  11. The canonical effect in statistical models for relativistic heavy ion collisions

    CERN Document Server

    Keränen, A

    2002-01-01

    Enforcing exact conservation laws instead of average ones in statistical thermal models for relativistic heavy ion reactions gives raise to so called canonical effect, which can be used to explain some enhancement effects when going from elementary (e.g. pp) or small (pA) systems towards large AA systems. We review the recently developed method for computation of canonical statistical thermodynamics, and give an insight when this is needed in analysis of experimental data.

  12. Photon-Photon Luminosities in Relativistic Heavy Ion Collisions at LHC Energies

    OpenAIRE

    Hencken, Kai; Trautmann, Dirk; Baur, Gerhard

    1995-01-01

    Effective photon-photon luminosities are calculated for various realistic hadron collider scenarios. The main characteristics of photon-photon processes at relativistic heavy-ion colliders are established and compared to the corresponding photon-photon luminosities at electron-positron and future Photon Linear Colliders (PLC). Higher order corrections as well as inelastic processes are discussed. It is concluded that feasible high luminosity Ca-Ca collisions at the Large Hadron Collider (LHC)...

  13. Photon-Photon Luminosities in Relativistic Heavy Ion Collisions at LHC Energies

    OpenAIRE

    Hencken, Kai; Trautmann, Dirk; Baur, Gerhard

    1994-01-01

    Effective photon-photon luminosities are calculated for various realistic hadron collider scenarios. The main characteristics of photon-photon processes at relativistic heavy-ion colliders are established and compared to the corresponding photon-photon luminosities at electron-positron and future Photon Linear Colliders (PLC). Higher order corrections as well as inelastic processes are discussed. It is concluded that feasible high luminosity Ca-Ca collisions at the Large Hadron Collider (LHC)...

  14. Net baryon density in Au+Au collisions at the Relativistic Heavy Ion Collider

    CERN Document Server

    Bass, S A; Srivastava, D K; Bass, Steffen A.; Müller, Berndt; Srivastava, Dinesh K.

    2003-01-01

    We calculate the net baryon rapidity distribution in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) in the framework of the Parton Cascade Model (PCM). Parton rescattering and fragmentation leads to a substantial increase in the net baryon density at mid-rapidity over the density produced by initial primary parton-parton scatterings. The PCM is able to describe the measured net baryon density at RHIC.

  15. Pair production with electron capture in peripheral collisions of relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, C.A.C.A. E-mail: bertu@if.ufrj.br; Dolci, D.D. E-mail: dolci@if.ufrj.br

    2001-02-26

    The production of electron-positron pairs with the capture of the electron in an atomic orbital is investigated for the conditions of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). Dirac wave functions for the leptons are used, taking corrections to orders of Z{alpha} into account. The dependence on the transverse momentum transfer is studied and the accuracy of the equivalent photon approximation is discussed as a function of the nuclear charge.

  16. Cluster approach to intranuclear cascade for relativistic heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, T.; Duarte, S.B.; Chung, K.C.; Nazareth, R.A.M.S.

    1982-08-23

    A new approach to the intranuclear cascade model for relativistic heavy-ion reactions is presented. The effect of nucleon concentration on the collision process is explicitly included. It is found that the contributions from the nonbinary processes are far from being negligible. Such processes are shown to broaden the angular distribution of inclusive proton spectra for /sup 20/Ne+/sup 238/U head-on collisions.

  17. Anisotropicity of Low Energy Direct Photons in Relativistic Heavy Ion Collisions

    CERN Document Server

    Koide, T

    2016-01-01

    We investigate the behavior of low energy photons radiated by deceleration processes of two colliding nuclei in relativistic heavy ion collisions, where their angular distribution reveals information of the initial geometric configurations. Such a property is reflected in the anisotropic parameter v_{2}, showing an increasing v_{2} as energy decreases, which is qualitatively different behavior from v_{2} from hadrons produced in the collisions.

  18. The Transverse Structure of the Baryon Source in Relativistic Heavy Ion Collisions

    OpenAIRE

    Polleri, A.; Mattiello, R.; Mishustin, I. N.; Bondorf, J. P.

    1999-01-01

    A direct method to reconstruct the transverse structure of the baryon source formed in a relativistic heavy ion collision is presented. The procedure makes use of experimentally measured proton and deuteron spectra and assumes that deuterons are formed via two-nucleon coalescence. The transverse density shape and flow profile are reconstructed for Pb+Pb collisions at the CERN-SPS. The ambiguity with respect to the source temperature is demonstrated and possible ways to resolve it are discussed.

  19. Baryon production and net-proton distributions in relativistic heavy ion collisions

    OpenAIRE

    Yang, C. B.; X Wang

    2011-01-01

    The higher order moments of the net-baryon distributions in relativistic heavy ion collisions are useful probes for the QCD critical point and fluctuations. We study the net-proton distributions and their moments in a simple model which considers the baryon stopping and pair production effects in the processes. It is shown that a single emission source model can explain the experimental data well. Centrality and energy dependence of the distributions and higher moments is discussed.

  20. Source chaoticity in relativistic heavy ion collisions at SPS and RHIC

    OpenAIRE

    Morita, Kenji; Muroya, Shin; NAKAMURA, Hiroki

    2006-01-01

    We investigate degree of coherence of pion sources produced in relativistic heavy ion collisions using multi-particle interferometry. In order to obtain ``true'' chaoticity, lambda^true from two-pion correlation functions measured in experiments, we make a correction for long-lived resonance decay contributions. Using this lambda^true and the weight factor which are obtained from parameter fitted to two- and three-pion correlation function, we calculate a chaotic fraction epsilon and the numb...

  1. Partonic Effects on Pion Interferometry at the Relativistic Heavy Ion Collider

    OpenAIRE

    Lin, Zi-wei; Ko, C. M.; Pal, Subrata

    2002-01-01

    Using a multiphase transport (AMPT) model that includes both initial partonic and final hadronic interactions, we study the pion interferometry at the Relativistic Heavy Ion Collider. We find that the two-pion correlation function is sensitive to the magnitude of the parton scattering cross section, which controls the parton density at which the transition from the partonic to hadronic matter occurs. Also, the emission source of pions is non-Gaussian, leading to source radii that can be more ...

  2. Boundary and expansion effects on two-pion correlation functions in relativistic heavy-ion collisions

    OpenAIRE

    Ayala, Alejandro; Sanchez, Angel

    2001-01-01

    We examine the effects that a confining boundary together with hydrodynamical expansion play on two-pion distributions in relativistic heavy-ion collisions. We show that the effects arise from the introduction of further correlations due both to collective motion and the system's finite size. As is well known, the former leads to a reduction in the apparent source radius with increasing average pair momentum K. However, for small K, the presence of the boundary leads to a decrease of the appa...

  3. Observing -violation in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    Rajarshi Ray

    2003-05-01

    Under certain situations, partons formed in heavy-ion collision experiments may expand out forming a shell-like structure. The partons in the outer shell subsequently hadronize, leaving a bubble of pure deconfined vacuum for a first-order quark–hadron phase transition. The bubble collapses and may eventually decay into particles which may thermalize to temperatures exceeding the electroweak transition temperature (∼ 100 GeV) at LHC. This will lead to the possibility of unsuppressed electroweak baryon number violating processes.

  4. Generation of high-energy neutron beam by fragmentation of relativistic heavy nuclei

    Science.gov (United States)

    Yurevich, Vladimir

    2016-09-01

    The phenomenon of multiple production of neutrons in reactions with heavy nuclei induced by high-energy protons and light nuclei is analyzed using a Moving Source Model. The Lorentz transformation of the obtained neutron distributions is used to study the neutron characteristics in the inverse kinematics where relativistic heavy nuclei bombard a light-mass target. The neutron beam generated at 0∘has a Gaussian shape with a maximum at the energy of the projectile nucleons and an energy resolution σE/E < 4% above 6 GeV.

  5. Formation and collapse of false vacuum bubbles in relativistic heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Rajarshi E-mail: rajarshi@iopb.res.in; Sanyal, Soma E-mail: sanyal@iopb.res.in; Srivastava, Ajit M. E-mail: ajit@iopb.res.in

    2002-12-30

    It is possible that under certain situations, in a relativistic heavy-ion collision, partons may expand out forming a shell like structure. We analyze the process of hadronization in such a picture for the case when the quark-hadron transition is of first order, and argue that the inside region of such a shell must correspond to a supercooled (to T=0) deconfined vacuum. Hadrons from that region escape out, leaving a bubble of pure deconfined vacuum with large vacuum energy. This bubble undergoes relativistic collapse, with highly Lorentz contracted bubble walls, and may concentrate the entire energy into extremely small regions. Eventually different portions of bubble wall collide, with the energy being released in the form of particle production. Thermalization of this system can lead to very high temperatures. With a reasonably conservative set of parameters, at LHC, the temperature of the hot spot can reach as high as 3 GeV, and well above it with more optimistic parameters. Such a hot spot can leave signals like large P{sub T} partons, dileptons, and enhanced production of heavy quarks. We also briefly discuss a speculative possibility where the electroweak symmetry may get restored in the highly dense region resulting from the decay of the bubble wall via the phenomenon of non-thermal symmetry restoration (which is usually employed in models of pre-heating after inflation). If that could happen then the possibility may arise of observing sphaleron induced baryon number violation in relativistic heavy-ion collisions.

  6. Angular distribution of Cherenkov radiation from relativistic heavy ions taking into account deceleration in the radiator

    Science.gov (United States)

    Bogdanov, O. V.; Fiks, E. I.; Pivovarov, Yu. L.

    2012-09-01

    Numerical methods are used to study the dependence of the structure and the width of the angular distribution of Vavilov-Cherenkov radiation with a fixed wavelength in the vicinity of the Cherenkov cone on the radiator parameters (thickness and refractive index), as well as on the parameters of the relativistic heavy ion beam (charge and initial energy). The deceleration of relativistic heavy ions in the radiator, which decreases the velocity of ions, modifies the condition of structural interference of the waves emitted from various segments of the trajectory; as a result, a complex distribution of Vavilov-Cherenkov radiation appears. The main quantity is the stopping power of a thin layer of the radiator (average loss of the ion energy), which is calculated by the Bethe-Bloch formula and using the SRIM code package. A simple formula is obtained to estimate the angular distribution width of Cherenkov radiation (with a fixed wavelength) from relativistic heavy ions taking into account the deceleration in the radiator. The measurement of this width can provide direct information on the charge of the ion that passes through the radiator, which extends the potentialities of Cherenkov detectors. The isotopic effect (dependence of the angular distribution of Vavilov-Cherenkov radiation on the ion mass) is also considered.

  7. Investigation of scintillation detectors for relativistic heavy ion calorimetry

    CERN Document Server

    Lozeva, R; Balabanski, D L; Gerl, J; Górska, M; Kojouharov, I; Kopatch, Y; Mandal, S; Schaffner, H; Wollersheim, H J

    2003-01-01

    The new DELTA E/E detection system, calorimeter telescope (CATE), for charge and mass determination of heavy ions at high energies (>=100 MeV/n) has been designed. CATE, a calorimeter telescope will consist of position sensitive Si detectors for DELTA E determination and scintillators, readout by either PIN diode or PMT, for total-E determination. Different scintillation detectors were tested with sup 1 sup 3 sup 0 Sn, sup 1 sup 8 sup 6 Pb, sup 1 sup 9 sup 7 Au and sup 2 sup 3 sup 8 U beams of (100-300) MeV/n ion energy. By properly selecting the beam species from the FRS and applying position corrections, an energy resolution of approx =0.5% FWHM was observed. The corresponding mass resolution of 1/200 is adequate for employment of CATE in the Fast Beam RISING campaign at GSI.

  8. Multi Module Modeling of Ultra-Relativistic Heavy Ion Collisions.

    Energy Technology Data Exchange (ETDEWEB)

    Magas, V. K.; Csernai, L. P. (László P.); Keranen, A.; Manninen, J.; Strottman, D. D. (Daniel D.)

    2002-01-01

    Multi Module Model is required for the realistic and detailed description of an ultrarelativistic heavy ion reaction. We are working in the framework of such a model: initial stages are described by Effective String Rope Model with expanding final streaks; hydrodynamical approach is used for the intermediate stages. This paper is mainly devoted to Third Module - the one dealing with Freeze Out (FO). Two possibilities are discussed in details: (A) freeze out at the constant time hypersurface, where the statistical production model is used to describe post FO particle species; and (B) simultaneous hadronization and freeze out from supercooled QGP. For the last case the ALCOR-like algorithm for calculation of the post FO particle species is presented, due to the fact that these do not have time to reach chemical equilibrium.

  9. Antihyperon-Production in Relativistic Heavy Ion Collision

    CERN Document Server

    Greiner, C; Greiner, Carsten; Leupold, Stefan

    2001-01-01

    Recently it has been shown that the observed antiproton yield in heavy-ion collisions at CERN-SpS energies can be understood by multi-pionic interactions which enforce local chemical equilibrium of the antiprotons with the nucleons and pions. Here we show that antihyperons are driven towards local chemical equilibrium with pions, nucleons and kaons on a timescale of less than 3 fm/c when applying a similar argument for the antihyperons by considering the inverse channel of annihilation reactions anti-Y + p to pions + kaons. These multi-mesonic reactions easily explain the antihyperon yields at CERN-SpS energies as advertised in pure thermal, hadronic models without the need of a quark gluon plasma phase. In addition, the argument also applies for AGS energies.

  10. Equilibration of matter in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    The chemical and thermal equilibration in the central zone of heavy-ion collisions at energies from AGS to SPS is studied within the microscopic transport model. Yields and energy spectra obtained for the central cell in the reaction are compared to the predictions of the thermal statistical model. It is found that kinetic, thermal, and chemical equilibration of the expanding hadronic matter are nearly approached for the period of 10-18 fm/c. Within this time the matter in the cell expands almost isentropically. For the bombarding energies around 40 AGeV the system crosses the critical point in the T - μB plane predicted by lattice QCD calculations. The net strangeness in the central cell is negative (though small). The characteristic kink in the T - μB diagrams corresponding to beginning of the equilibrated phase is observed for all energies. The origin of this phenomenon deserves further investigation. (author)

  11. Production of photons in relativistic heavy-ion collisions

    Science.gov (United States)

    Paquet, Jean-François; Shen, Chun; Denicol, Gabriel S.; Luzum, Matthew; Schenke, Björn; Jeon, Sangyong; Gale, Charles

    2016-04-01

    In this work it is shown that the use of a hydrodynamical model of heavy-ion collisions which incorporates recent developments, together with updated photon emission rates, greatly improves agreement with both ALICE and PHENIX measurements of direct photons, supporting the idea that thermal photons are the dominant source of direct photon momentum anisotropy. The event-by-event hydrodynamical model uses the impact parameter dependent Glasma model (IP-Glasma) initial states and includes, for the first time, both shear and bulk viscosities, along with second-order couplings between the two viscosities. The effect of both shear and bulk viscosities on the photon rates is studied, and those transport coefficients are shown to have measurable consequences on the photon momentum anisotropy.

  12. The production of photons in relativistic heavy-ion collisions

    CERN Document Server

    Paquet, Jean-François; Denicol, Gabriel S; Luzum, Matthew; Schenke, Björn; Jeon, Sangyong; Gale, Charles

    2015-01-01

    In this work it is shown that the use of a hydrodynamical model of heavy ion collisions which incorporates recent developments, together with updated photon emission rates greatly improves agreement with both ALICE and PHENIX measurements of direct photons, supporting the idea that thermal photons are the dominant source of direct photon momentum anisotropy. The event-by-event hydrodynamical model uses IP-Glasma initial states and includes, for the first time, both shear and bulk viscosities, along with second order couplings between the two viscosities. The effect of both shear and bulk viscosities on the photon rates is studied, and those transport coefficients are shown to have measurable consequences on the photon momentum anisotropy.

  13. Final Report for Project ``Theory of ultra-relativistic heavy-ion collisions''

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich W. Heinz

    2012-11-09

    In the course of this project the Ohio State University group led by the PI, Professor Ulrich Heinz, developed a comprehensive theoretical picture of the dynamical evolution of ultra-relativistic heavy-ion collisions and of the numerous experimental observables that can be used to diagnose the evolving and short-lived hot and dense fireball created in such collisions. Starting from a qualitative understanding of the main features based on earlier research during the last decade of the twentieth century on collisions at lower energies, the group exploited newly developed theoretical tools and the stream of new high-quality data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory (which started operations in the summer of the year 2000) to arrive at an increasingly quantitative description of the experimentally observed phenomena. Work done at Ohio State University (OSU) was instrumental in the discovery during the years 2001-2003 that quark-gluon plasma (QGP) created in nuclear collisions at RHIC behaves like an almost perfect liquid with minimal viscosity. The tool of relativistic fluid dynamics for viscous liquids developed at OSU in the years 2005-2007 opened the possibility to quantitatively determine the value of the QGP viscosity empirically from experimental measurements of the collective flow patterns established in the collisions. A first quantitative extraction of the QGP shear viscosity, with controlled theoretical uncertainty estimates, was achieved during the last year of this project in 2010. OSU has paved the way for a transition of the field of relativistic heavy-ion physics from a qualitative discovery stage to a new stage of quantitative precision in the description of quark-gluon plasma properties. To gain confidence in the precision of our theoretical understanding of quark-gluon plasma dynamics, one must test it on a large set of experimentally measured observables. This achievement report demonstrates that we have, at

  14. Large fragment production calculations in relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    The abrasion-ablation model is briefly described and then used to calculate cross sections for production of large fragments resulting from target or projectile fragmentation in high-energy heavy-ion collisions. The number of nucleons removed from the colliding nuclei in the abrasion stage and the excitation energy of the remaining fragments (primary products) are calculated with the geometrical picture of two different models: the fireball and the firestreak models. The charge-to-mass dispersion of the primary products is calculated using either a model which assumes no correlations between proton and neutron positions inside the nucleus (hypergeometric distribution) or a model based upon the zero-point oscillations of the giant dipole resonance (NUC-GDR). Standard Weisskopf--Ewing statistical evaporation calculations are used to calculate final product distributions. Results of the pure abrasion-ablation model are compared with a variety of experimental data. The comparisons show the insufficiency of the extra-surface energy term used in the abrasion calculations. A frictional spectator interaction (FSI) is introduced which increases the average excitation energy of the primary products, and improves the results considerably in most cases. Agreements and discrepancies of the results calculated with the different theoretical assumptions and the experimental data are studied. Of particular relevance is the possibility of observing nuclear ground-state correlations.Results of the recently completed experiment of fragmentation of 213 Mev/A 40Ar projectiles are studied and shown not to be capable of answering that question unambiguously. But predictions for the upcoming 48Ca fragmentation experiment clearly show the possibility of observing correlation effects. 78 references

  15. A 3+1 dimensional viscous hydrodynamic code for relativistic heavy ion collisions

    Science.gov (United States)

    Karpenko, Iu.; Huovinen, P.; Bleicher, M.

    2014-11-01

    We describe the details of 3+1 dimensional relativistic hydrodynamic code for the simulations of quark-gluon/hadron matter expansion in ultra-relativistic heavy ion collisions. The code solves the equations of relativistic viscous hydrodynamics in the Israel-Stewart framework. With the help of ideal-viscous splitting, we keep the ability to solve the equations of ideal hydrodynamics in the limit of zero viscosities using a Godunov-type algorithm. Milne coordinates are used to treat the predominant expansion in longitudinal (beam) direction effectively. The results are successfully tested against known analytical relativistic inviscid and viscous solutions, as well as against existing 2+1D relativistic viscous code. Catalogue identifier: AETZ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETZ_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 13 825 No. of bytes in distributed program, including test data, etc.: 92 750 Distribution format: tar.gz Programming language: C++. Computer: any with a C++ compiler and the CERN ROOT libraries. Operating system: tested on GNU/Linux Ubuntu 12.04 x64 (gcc 4.6.3), GNU/Linux Ubuntu 13.10 (gcc 4.8.2), Red Hat Linux 6 (gcc 4.4.7). RAM: scales with the number of cells in hydrodynamic grid; 1900 Mbytes for 3D 160×160×100 grid. Classification: 1.5, 4.3, 12. External routines: CERN ROOT (http://root.cern.ch), Gnuplot (http://www.gnuplot.info/) for plotting the results. Nature of problem: relativistic hydrodynamical description of the 3-dimensional quark-gluon/hadron matter expansion in ultra-relativistic heavy ion collisions. Solution method: finite volume Godunov-type method. Running time: scales with the number of hydrodynamic cells; typical running times on Intel(R) Core(TM) i7-3770 CPU @ 3.40 GHz, single thread mode, 160

  16. Emission of medium-heavy fragments in asymetric heavy ion collisions at intermediate and relativistic incident energies

    International Nuclear Information System (INIS)

    For the study of the emission of medium-heavy fragments in asymmetric heavy ion collisions a series of experiments was performed and thereby following systems at intermediate and relativistic incident energies studied: 84Kr+197Au at E/A=35 MeV, 40Ar+197Au at E/A=30 MeV, respectively 220 MeV, and 12C+197Au at E/A=99 MeV, 301 MeV, 601 MeV, respectively 1105 MeV. In the experiments highly resolving detector telescopes with low thresholds were applied to the measurement of the energy and angular distributions of the medium-heavy fragments. The spectra were analyzed in the picture of longitudinally moving sources. Thereby beyond the production cross sections the angular distributions, the decreasement parameters in the high-energetic region of the energy spectra, and the position of the maxima were determined as characteristic parameters. The following picture resulted: The production cross sections for medium-heavy fragments showed a steep increasement and then a saturation, but with a strong projectile dependence. The charge distributions could be described by a power law, the parameter of which showed a universal dependence on the total incident energy. In the angular distributions the transition from an anisotropic emission at low energies to an isotropic emission from a nearly resting source at relativistic energies was distinctly to be recognized. The decreasement parameters of the energy distribution increased - for different projectiles differently strongly - logarithmically with growing incident energy. And the maxima of the energy distribution travelled with growing incident energy to smaller and smaller fragment energies. From this systematics a schematic model of the fragmentation can be obtained. (orig./HSI)

  17. Electromagnetic properties of light and heavy baryons in the relativistic quark model

    Energy Technology Data Exchange (ETDEWEB)

    Nicmorus Marinescu, Diana

    2007-06-14

    One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N{yields}{delta}{gamma} transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit

  18. Electromagnetic properties of light and heavy baryons in the relativistic quark model

    International Nuclear Information System (INIS)

    One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N→Δγ transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit within this

  19. A new relativistic hydrodynamics code for high-energy heavy-ion collisions

    CERN Document Server

    Okamoto, Kazuhisa; Nonaka, Chiho

    2016-01-01

    We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, Landau-Khalatnikov solution, propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions.We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates.

  20. Heavy flavor Production and Interactions in Relativistic Heavy-Ion Collisions in CMS Experiment

    CERN Document Server

    Xie, Wei

    2016-01-01

    This paper presents the CMS measurements of quarkonia and open heavy flavor production in \\pp, \\pPb, and \\PbPb collisions at \\sqrtsnn = 2.76 and 5.02 TeV. A brief outlook of the near-future CMS heavy flavor physics analyses is provided at the end.

  1. Heavy flavor production and interactions in relativistic heavy ion collisions in CMS experiments

    CERN Document Server

    Xie, Wei

    2016-01-01

    This paper presents the CMS measurements of quarkonia and open heavy flavor production in \\pp, \\pPb, and \\PbPb collisions at \\sqrtsnn = 2.76 and 5.02 TeV. A brief outlook of the near-future CMS heavy flavor physics analyses is provided at the end.

  2. An Algorithm for Selecting QGP Candidate Events from Relativistic Heavy Ion Collision Data Sample

    CERN Document Server

    Lian Shou Liu; Yuan, H B; Lianshou, Liu; Qinghua, Chen; Yuan, Hu

    1998-01-01

    The formation of quark-gluon plasma (QGP) in relativistic heavy ion collision, is expected to be accompanied by a background of ordinary collision events without phase transition. In this short note an algorithm is proposed to select the QGP candidate events from the whole event sample. This algorithm is based on a simple geometrical consideration together with some ordinary QGP signal, e.g. the increasing of $K/\\pi$ ratio. The efficiency of this algorithm in raising the 'signal/noise ratio' of QGP events in the selected sub-sample is shown explicitly by using Monte-Carlo simulation.

  3. Ultra-relativistic heavy-ion collisions - a hot cocktail of hydrodynamics, resonances and jets

    Directory of Open Access Journals (Sweden)

    Zabrodin E.

    2015-01-01

    Full Text Available Ultra-relativistic heavy-ion collisions at energies of RHIC and LHC are considered. For comparison with data the HYDJET++ model, which contains the treatment of both soft and hard processes, is employed. The study focuses mainly on the interplay of ideal hydrodynamics, final state interactions and jets, and its influence on the development of harmonics of the anisotropic flow. It is shown that jets are responsible for violation of the number-of-constituent-quark (NCQ scaling at LHC energies. The interplay between elliptic and triangular flows and their contribution to higher flow harmonics and dihadron angular correlations, including ridge, is also discussed.

  4. Relativistic quantum dynamics in strong fields: Photon emission from heavy, few-electron ions

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsche, S. [Kassel Univ. (Germany). Inst. fuer Physik; Indelicato, P. [Lab. Kastler Brossel, Ecole Normale Superieure et Universite Pierre et Marie Curie, Paris (France); Stoehlker, T. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik

    2005-03-01

    Recent progress in the study of the photon emission from highly-charged heavy ions is reviewed. These investigations show that high-Z ions provide a unique tool for improving the understanding of the electron-electron and electron-photon interaction in the presence of strong fields. Apart from the bound-state transitions, which are accurately described in the framework of quantum electrodynamics, much information has been obtained also from the radiative capture of (quasi-) free electrons by high-Z ions. Many features in the observed spectra hereby confirm the inherently relativistic behavior of even the simplest compound quantum systems in nature. (orig.)

  5. Viscosity to entropy ratio of QGP in relativistic heavy ion collision: Hard thermal loop corrections

    Science.gov (United States)

    Pari, Sharareh Mehrabi; Javidan, Kurosh; Shahri, Fatemeh Taghavi

    2016-06-01

    In this work, we report on our computation results for the best value of the shear viscosity to entropy ratio of quark-gluon plasma produced in the relativistic Au-Au collisions at s NN = 200GeV. Time evolution of heavy quarks distribution functions is calculated by solving the Fokker-Planck evolution equation using the new technique: Iterative Laplace transform method. We compute the drag and diffusion coefficients by considering the hard thermal loop corrections and also temperature dependence running strong coupling, up to complete interactions of leading order.

  6. Re-hardening of hadron transverse mass spectra in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    P K Sahu; N Otuka; M Isse; Y Nara; A Ohnishi

    2006-05-01

    We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65+65 A GeV by using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma formation.

  7. Nuclear fragmentation energy and momentum transfer distributions in relativistic heavy-ion collisions

    Science.gov (United States)

    Khandelwal, Govind S.; Khan, Ferdous

    1989-01-01

    An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.

  8. Study on the method of mini-jet identification in relativistic heavy ion collisions

    CERN Document Server

    De-sheng, Li; Gang, Chen

    2011-01-01

    In this thesis a set of methods identifying minijet from final state particles in the relativistic heavy ion collision events is established and the parameter dependence has been investigated in Au+Au collisions at $\\sqrt s= 200$GeV using a multiphase transport model (AMPT). It is found that the number of minijets reduces with the increasing of collision parameter and raises with the increasing of c.m energy. Furthermore, we analyze the rapidity and momentum distribution inside minijets identified using this method.

  9. HBT Parameters and Space-Momentum Correlations in Relativistic Heavy-Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    张景波; 霍雷; 张卫宁; 李新华; 许怒; 刘亦铭

    2001-01-01

    Using the relativistic quantum molecular dynamics approach, with a correlation after-burner, the physics of the transverse momentum dependence of the Hanbury-Brown and Twiss parameters is studied for Au t Au, Si + Si and p + p collisions at the centre-of-mass energy v s = 200 AGeV. The results indicate that the space-momentum correlations would affect such dependence in both heavy-ion and elementary collisions. The size parameters as a function of the transverse mass mt are sensitive to the degree of space-momentum correlations.

  10. Analysis of calorimetry in ultra relativistic heavy ion collisions at 200 GeV per nucleon

    International Nuclear Information System (INIS)

    We draw up in this thesis the statement of the calorimetry analysis in ultra relativistic heavy ion collisions at 200 GeV/A. NA38 experiment studies the production of dimuons correlated with neutral transverse energy flow detected by an electromagnetic calorimeter. J/Ψ suppression in central collisions could be a signature of the quark-gluon plasma (Q.G.P.). Characteristics and limits of the apparatus are briefly described. On the other hand, calorimetry measurements and analysis methods are studied in details and future developments are proposed

  11. Coherent photon-photon processes in disruptive and non-disruptive relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Using an impact parameter formulation, differential probability distributions and cross sections for the production of lepton pairs via the photon-photon mechanism are calculated for relativistic heavy-ion collisions. The characteristic features of lepton pair production in disruptive as well as in non-disruptive A-A collisions are studied. Cross sections can be large, the very low k perpendicularto -values of the pairs will help to distinguish these pairs from the ones originating from other sources like Drell-Yan or thermal production. (orig.)

  12. Ultraviolet energy dependence of particle production sources in relativistic heavy-ion collisions

    CERN Document Server

    Wolschin, Georg

    2015-01-01

    The energy dependence of particle production sources in relativistic heavy-ion collisions is investigated from RHIC to LHC energies. Whereas charged-hadron production in the fragmentation sources follows a ln(s_NN/s_0) law, particle production in the mid-rapidity gluon-gluon source exhibits a much stronger dependence proportional to ln^3(s_NN/s_0), and becomes dominant between RHIC and LHC energies. The production of particles with pseudorapidities beyond the beam rapidity is also discussed.

  13. Hanbury-Brown/Twiss Interferometry for Relativistic Heavy-Ion Collisions: Theoretical Aspects

    OpenAIRE

    Heinz, Ulrich

    1996-01-01

    I discuss two-particle intensity interferometry as a method to extract from measured 1- and 2-particle momentum spectra information on the space-time geometry and dynamics of the particle emitting source. Particular attention is given to the rapid expansion and short lifetime of the sources created in relativistic heavy-ion collisions. Model-independent expressions for the HBT size parameters in terms of the space-time variances of the source are derived, and a new parametrization of the corr...

  14. The Future Of Spin Physics At BNL

    Science.gov (United States)

    Aronson, Samuel; Deshpande, Abhay

    2007-06-01

    The Relativistic Heavy Ion Collider (RHIC) at BNL is the world's only polarized proton-proton collider. Collisions at center-of-mass energies up to 500 GeV and beam polarizations approaching 70% (longitudinal or transverse) are provided to two experiments, STAR and PHENIX, at luminosities ⩾ 1032/cm2/sec. Transverse polarized beam has also been provided to the BRAHMS experiment. Measurements that bear on the important question of the spin content of the nucleon are beginning to appear. Over the next 10 years, as the performance of polarized proton running at RHIC is farmer developed, the Spin Physics program at RHIC will provide definitive measurements of the contributions to the proton's spin of the gluon, the sea quarks and the orbital motion of the partons in the proton's wave function. We plan to extend the reach of our study of the role of spin in QCD with the development of "eRHIC," which will provide polarized e-p collisions to a new detector.

  15. THE FUTURE OF SPIN PHYSICS AT BNL.

    Energy Technology Data Exchange (ETDEWEB)

    ARONSON, S.; DESHPANDE, A.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) at BNL is the world's only polarized proton-proton collider. Collisions at center-of-mass energies up to 500 GeV and beam polarizations approaching 70% (longitudinal or transverse) are provided to two experiments, STAR and PHENIX, at luminosities {ge} 10{sup 32}/cm{sup 2}/sec. Transverse polarized beam has also been provided to the BRAHMS experiment. Measurements that bear on the important question of the spin content of the nucleon are beginning to appear. Over the next 10 years, as the performance of polarized proton running at RHIC is further developed, the Spin Physics program at RHIC will provide definitive measurements of the contributions to the proton's spin of the gluon, the sea quarks and the orbital motion of the partons in the proton's wave function. We plan to extend the reach of our study of the role of spin in QCD with the development of ''eRHIC'', which will provide polarized e-p collisions to a new detector.

  16. Highlights from BNL and RHIC 2014

    CERN Document Server

    Tannenbaum, M J

    2015-01-01

    Highlights of news from Brookhaven National Laboratory (BNL) and results from the Relativistic Heavy Ion Collider (RHIC) in the period July 2013-June 2014 are presented. It was a busy year for news, most notably a U. S. Government shutdown for 16 days beginning October 1, 2013 due to the lack of an approved budget for FY2014. Even with this unusual government activity, the $\\sqrt{s_{NN}}=200$ GeV Au+Au Run14 at RHIC was the best ever with integrated luminosity exceeding the sum of all previous runs. Additionally there was a brief He$^3$+Au run to continue the study of collective flow in small systems which was reinforced by new results presented on identified particle flow in d+Au. The other scientific highlights are also mostly concerned with ``soft (low $p_T$)'' physics complemented by the first preliminary results of reconstructed jets from hard-scattered partons in Au+Au collisions at RHIC . The measurements of transverse energy ($E_T$) spectra in p-p, d+Au and Au+Au collisions, which demonstrated last ye...

  17. Critical phenomena in a disc-percolation model and their application to relativistic heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    KE Hong-Wei; XU Ming-Mei; LIU Lian-Shou

    2009-01-01

    By studying the critical phenomena in continuum-percolation of discs, we find a new approach to locate the critical point, i.e.using the inflection point of P_∞ as an evaluation of the percolation threshold.The susceptibility, defined as the derivative of P_∞, possesses a finite-size scaling property, where the scaling exponent is the reciprocal of ν, the critical exponent of the correlation length.A possible application of this approach to the study of the critical phenomena in relativistic heavy ion collisions is discussed.The critical point for deconfinement can be extracted by the inflection point of P_(QGP)-the probability for the event with QGP formation.The finite-size scaling of its derivative can give the critical exponent ν, which is a rare case that can provide an experimental measure of a critical exponent in heavy ion collisions.

  18. Thermal photon production from gluon fusion induced by magnetic fields in relativistic heavy-ion collisions

    CERN Document Server

    Ayala, Alejandro; Dominguez, C A; Hernandez, L A

    2016-01-01

    We compute the production of thermal photons in relativistic heavy-ion collisions by gluon fusion in the presence of an intense magnetic field, and during the early stages of the reaction. This photon yield is an excess over calculations that do not consider magnetic field effects. We add this excess to recent hydrodynamic calculations that are close to describing the experimental transverse momentum distribution in RHIC and LHC. We then show that with reasonable values for the temperature, magnetic field strength, and strong coupling constant, our results provide a very good description of such excess. These results support the idea that the origin of at least some of the photon excess observed in heavy-ion experiments may arise from magnetic field induced processes.

  19. Minimizing statistical and systematic bias in transverse momentum correlations for relativistic heavy-ion collisions

    CERN Document Server

    Ray, Robert L

    2016-01-01

    Two-particle correlation measurements and analysis are an important component of the relativistic heavy-ion physics program. In particular, particle pair-number correlations on two-dimensional transverse momentum ($p_t$) allow unique access to soft, semi-hard and hard-scattering processes in these collisions. Precise measurements of this type of correlation are essential for understanding the dynamics in heavy-ion collisions. However, transverse momentum correlation measurements are especially vulnerable to statistical and systematic biases. In this paper the origins of these large bias effects are explained and mathematical correlation forms are derived from mean-$p_t$ fluctuation quantities in the literature in an effort to minimize bias. Monte Carlo simulations are then used to test the degree to which each correlation definition leads to unbiased results in realistic applications. Several correlation forms are shown to be unacceptable for data analysis applications while several others are shown to reprod...

  20. Intermediate pT phenomena in relativistic heavy-ion collisions

    Science.gov (United States)

    Ayala, Alejandro

    2010-07-01

    Particles produced with intermediate values of transverse momentum 1-2≲pT≲4-5 GeV, exhibit both thermal and jet-like features making them an ideal testing ground of the properties of the quark-gluon plasma produced in the aftermath of a relativistic heavy-ion collision, which have been only inferred from the behavior of either soft or hard modes. In this work I discuss two phenomena that that are observed in this transverse momentum window: the suppression of the single, non-photonic electron yield compared to normalized p+p collisions and the spin alignment of vector mesons. I make use of a recombination scenario of either a heavy or a fast quark with thermal ones and show that this way of describing hadron formation can account for the afore mentioned phenomena.

  1. Fourth workshop on experiments and detectors for a relativistic heavy ion collider

    International Nuclear Information System (INIS)

    This report contains papers on the following topics: physics at RHIC; flavor flow from quark-gluon plasma; space-time quark-gluon cascade; jets in relativistic heavy ion collisions; parton distributions in hard nuclear collisions; experimental working groups, two-arm electron/photon spectrometer collaboration; total and elastic pp cross sections; a 4π tracking TPC magnetic spectrometer; hadron spectroscopy; efficiency and background simulations for J/ψ detection in the RHIC dimuon experiment; the collision regions beam crossing geometries; Monte Carlo simulations of interactions and detectors; proton-nucleus interactions; the physics of strong electromagnetic fields in collisions of relativistic heavy ions; a real time expert system for experimental high energy/nuclear physics; the development of silicon multiplicity detectors; a pad readout detector for CRID/tracking; RHIC TPC R ampersand D progress and goals; development of analog memories for RHIC detector front-end electronic systems; calorimeter/absorber optimization for a RHIC dimuon experiment; construction of a highly segmented high resolution TOF system; progress report on a fast, particle-identifying trigger based on ring-imaging and highly integrated electronics for a TPC detector

  2. Nonperturbative tuning of an improved relativistic heavy-quark action with application to bottom spectroscopy

    CERN Document Server

    Aoki, Yasumichi; Flynn, Jonathan M; Izubuchi, Taku; Lehner, Christoph; Li, Min; Peng, Hao; Soni, Amarjit; Van de Water, Ruth S; Witzel, Oliver

    2012-01-01

    We calculate the masses of bottom mesons using an improved relativistic action for the b-quarks and the RBC/UKQCD Iwasaki gauge configurations with 2+1 flavors of dynamical domain-wall light quarks. We analyze configurations with two lattice spacings: a^{-1} = 1.729 GeV (a ~ 0.11 fm) and a^{-1} = 2.281 GeV (a ~ 0.086 fm). We use an anisotropic, clover-improved Wilson action for the b-quark, and tune the three parameters of the action nonperturbatively such that they reproduce the experimental values of the B_s and B_s* heavy-light meson states. The masses and mass-splittings of the low-lying bottomonium states (such as the eta_b and Upsilon) can then be computed with no additional inputs, and comparison between these predictions and experiment provides a test of the validity of our method. We obtain bottomonium masses with total uncertainties of ~0.5-0.6% and fine-structure splittings with uncertainties of ~35-45%; for all cases we find good agreement with experiment. The parameters of the relativistic heavy-...

  3. Particle production in Ultra-relativistic Heavy-Ion Collisions : A Statistical-Thermal Model Review

    CERN Document Server

    Tiwari, S K

    2013-01-01

    The current status of various thermal and statistical descriptions of particle production in the ultra-relativistic heavy-ion collisions experiments is presented in detail. We discuss the formulation of various types of thermal models of a hot and dense hadron gas (HG) and the methods incorporated in implementing the interactions between hadrons. We first obtain the parametrizations of center-of-mass energy ($\\sqrt{s_{NN}}$) in terms of temperature ($T$) and baryon chemical potential ($\\mu_B$) obtained by analyzing the particle ratios at the freeze-out over a broad energy range from the lowest Alternating Gradient Synchrotron (AGS) energy to the highest Relativistic Heavy-Ion Collider (RHIC) energies. The results of various thermal models together with the experimental results for the various ratios of particles are then compared. We have derived some new universal conditions emerging at the chemical freeze-out of HG fireball which demonstrate the independence with respect to the energy as well as the structu...

  4. Study of Particle Production and Nuclear Fragmentation in Relativistic Heavy-Ion Collisions in Nuclear Emulsions

    CERN Multimedia

    2002-01-01

    % EMU11 \\\\ \\\\ We propose to use nuclear emulsions for the study of nuclear collisions of $^{207}$Pb, $^{197}$Au, and any other heavy-ion beams when they are available. We have, in the past, used $^{32}$S at 200A~GeV and $^{16}$O at 200A and 60A~GeV from CERN (Experiment EMU08) and at present the analysis is going on with $^{28}$Si beam from BNL at 14.5A~GeV. It will be important to compare the previous and the present investigations with the new $^{207}$Pb beam at 60-160A~GeV. We want to measure in nuclear emulsion, on an event by event basis, shower particle multiplicity, pseudorapidity density and density fluctuations of charged particles, charge multiplicity and angular distributions of projectile fragments, production and interaction cross-sections of heavily ionizing particles emitted from the target fragmentation. Special emphasis will be placed on the analysis of events produced in the central collisions which are selected on the basis of low energy fragments emitted from the target excitation. It woul...

  5. A heavy ion spectrometer system for the measurement of projectile fragmentation of relativistic heavy ions

    International Nuclear Information System (INIS)

    The Heavy Ion Spectrometer System (HISS) at the LBL Bevalac provided a unique facility for measuring projectile fragmentation cross sections important in deconvolving the Galactic Cosmic Ray (GCR) source composition. The general characteristics of the apparatus specific to this application are described and the main features of the event reconstruction and analysis used in the TRANSPORT experiment are discussed

  6. Cooling Scheme for BNL-Built LHC Magnets

    CERN Document Server

    Ostojic, R; Van Weelderen, R; Willen, E H; Wu, K C

    1999-01-01

    Brookhaven National Laboratory (BNL) will provide four types of magnets, identified as D1, D2, D3 and D4, for the Insertion Regions of the Large Hadron Collider (LHC) as part of an international collaboration. These magnets utilize the dipole coil design of the Relativistic Heavy Ion Collider (RHIC) at BNL, for performance, reliability and cost reasons. The magnet cold mass and cryostat have been designed to ensure that these magnets meet all performance requirements in the LHC sloped tunnel using its cryogenic distribution system. D1 is a RHIC arc dipole magnet. D2 and D4 are 2-in-1 magnets, two coils in one cold mass, in a cryostat. D3 is a 1-in-1 magnet, one coil in one cold mass, with two cold masses side by side in a cryostat. D1 and D4 will be cooled by helium II at 1.9 K using a bayonet heat exchanger similar to the main cooling system of LHC. D2 and D3 will be cooled by liquid helium at 4.5 K using a Two-Feed scheme. A detailed description of the cooling scheme for these magnets, their cryostats, spec...

  7. Performance on the low charge state laser ion source in BNL

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, M.; Alessi, J.; Beebe, E.; Costanzo, M.; DeSanto, L.; Jamilkowski, J.; Kanesue, T.; Lambiase, R.; Lehn, D.; Liaw, C. J.; McCafferty, D.; Morris, J.; Olsen, R.; Pikin, A.; Raparia, D.; Steszyn, A.; Ikeda, S.

    2015-09-07

    On March 2014, a Laser Ion Source (LIS) was commissioned which delivers high-brightness, low-charge-state heavy ions for the hadron accelerator complex in Brookhaven National Laboratory (BNL). Since then, the LIS has provided many heavy ion species successfully. The low-charge-state (mostly singly charged) beams are injected to the Electron Beam Ion Source (EBIS), where ions are then highly ionized to fit to the following accelerator’s Q/M acceptance, like Au32+. Recently we upgraded the LIS to be able to provide two different beams into EBIS on a pulse-to-pulse basis. Now the LIS is simultaneously providing beams for both the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory (NSRL).

  8. Charged Particle Multiplicity and Open Heavy Flavor Physics in Relativistic Heavy Ion Collisions at the LHC

    Science.gov (United States)

    Chen, Yujiao

    In this thesis, two independent measurements are presented: the measurements of centrality dependence and pseudo-rapidity dependence of charged particle multiplicities, and the measurements of centrality dependence of open heavy flavor suppression. These measurements are carried out with the Pb+Pb collisions data at the LHC energy sNN = 2.76 TeV with the ATLAS detector. For the charged particle measurements, charged particles are reconstructed with two algorithms (2-point "tracklet" and full tracking) from the pixel detector only. Measurements are presented of the per-event charged particle density distribution, dNch /deta and the average charged particle multiplicity in the pseudo-rapidity interval |eta| measurements at the LHC and RHIC. The variation of the mid-rapidity charged particle yield per colliding nucleon pair with the number of participants is consistent with the lower sNN results measured at RHIC. The shape of the dNch/deta distribution is found to be independent of centrality within the systematic uncertainties of the measurement. For the open heavy flavor suppression measurements, muons identified by the muon spectrometer are classified as heavy flavor decays and background contributions by using a fitting procedure with templates from Monte Carlo samples. Results are presented for the per-event muon yield as a function of muon transverse momentum, p T, over the range of 4 measure, muon production from heavy quark decays is found to be suppressed by a centrality-dependent factor that increases smoothly from peripheral to central collisions. Muon production is suppressed by approximately a factor of two in central collisions relative to peripheral collisions. Within the experimental errors, the observed suppression is independent of muon pT for all centralities. Furthermore, the p T dependence of the relative muon yields in Pb+Pb collisions to p+p collisions with the same center of mass collision energy per nucleon is presented by the nuclear

  9. Beam energy dependence of pseudorapidity distributions of charged particles produced in relativistic heavy-ion collisions

    Science.gov (United States)

    Basu, Sumit; Nayak, Tapan K.; Datta, Kaustuv

    2016-06-01

    Heavy-ion collisions at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN probe matter at extreme conditions of temperature and energy density. Most of the global properties of the collisions can be extracted from the measurements of charged-particle multiplicity and pseudorapidity (η ) distributions. We have shown that the available experimental data on beam energy and centrality dependence of η distributions in heavy-ion (Au +Au or Pb +Pb ) collisions from √{sNN}=7.7 GeV to 2.76 TeV are reasonably well described by the AMPT model, which is used for further exploration. The nature of the η distributions has been described by a double Gaussian function using a set of fit parameters, which exhibit a regular pattern as a function of beam energy. By extrapolating the parameters to a higher energy of √{sNN}=5.02 TeV, we have obtained the charged-particle multiplicity densities, η distributions, and energy densities for various centralities. Incidentally, these results match well with some of the recently published data by the ALICE Collaboration.

  10. Azimuthal anisotropy and formation of an extreme state of strongly interacting matter at the relativistic heavy-ion collider (RHIC)

    NARCIS (Netherlands)

    Okorokov, V. A.

    2009-01-01

    Experimental results obtained by studying the azimuthal anisotropy of final states in nucleus-nucleus interactions at the energies of the relativistic heavy-ion collider (RHIC) are systematized. The medium is found to exhibit a pronounced collective behavior, which is likely to be formed at an early

  11. Use of relativistic rise in ionization chambers for measurement of high energy heavy nuclei

    Science.gov (United States)

    Barthelmy, S. D.; Israel, M. H.; Klarmann, J.; Vogel, J. S.

    1983-01-01

    A balloon-borne instrument has been constructed to measure the energy spectra of cosmic-ray heavy nuclei in the range of about 0.3 to about 100 GeV/amu. It makes use of the relativistic rise portion of the Bethe-Bloch curve in ionization chambers for energy determination in the 10- to 100-GeV/amu interval. The instrument consists of six layers of dual-gap ionization chambers for energy determination above 10 GeV/amu. Charge is determined with a NE114 scintillator and a Pilot 425 plastic Cerenkov counter. A CO2 gas Cerenkov detector (1 atm; threshold of 30 GeV/amu) calibrates the ion chambers in the relativistic rise region. The main emphasis of the instrument is the determination of the change of the ratio of Iron (26) to the Iron secondaries (21-25) in the energy range of 10 to 100 GeV/amu. Preliminary data from a balloon flight in the fall of 1982 from Palestine, TX is presented.

  12. Viscous evolution of the rapidity distribution of matter created in relativistic heavy-ion collisions

    Science.gov (United States)

    Bożek, Piotr

    2008-03-01

    The longitudinal hydrodynamic expansion of the fluid created in relativistic heavy-ion collisions is considered taking into account shear viscosity. We consider the dynamics of a non-boost-invariant energy density of the fluid in 1+1 dimensions, using the proper time and the space-time rapidity. Both a nonvanishing viscosity and a soft equation of state make the final particle distributions in rapidity narrower. The width of the initial Gaussian rapidity distribution and its central energy density are fitted to reproduce the rapidity distributions of pions and kaons as measured by the BRAHMS Collaboration. The presence of viscosity has dramatic consequences on the value of the initial energy density. Dissipative processes and the reduction of the longitudinal work due to the shear viscosity increase the total entropy and the particle multiplicity at central rapidities. Viscous corrections make the longitudinal velocity of the fluid stay close to the Bjorken scaling flow vz=z/t through the evolution.

  13. Analyzing flow anisotropies with excursion sets in relativistic heavy-ion collisions

    CERN Document Server

    Mohapatra, Ranjita K; Srivastava, Ajit M

    2011-01-01

    We show that flow anisotropies in relativistic heavy-ion collisions can be analyzed using a certain technique of shape analysis of excursion sets recently proposed by us for CMBR fluctuations to investigate anisotropic expansion history of the universe. The technique analyzes shapes (sizes) of patches above (below) certain threshold value for transverse energy/particle number (the excursion sets) as a function of the azimuthal angle and rapidity. Modeling flow by imparting extra anisotropic momentum to the momentum distribution of particles from HIJING, we compare the resulting distributions for excursion sets at two different azimuthal angles. Angles with maximum difference in the two distributions identify the event plane, and the magnitude of difference in the two distributions relates to the magnitude of momentum anisotropy, i.e. elliptic flow.

  14. Fluctuations in Charged Particle Multiplicities in Relativistic Heavy-Ion Collisions

    CERN Document Server

    Mukherjee, Maitreyee; Choudhury, Subikash; Nayak, Tapan K

    2016-01-01

    Multiplicity distributions of charged particles and their event-by-event fluctuations have been compiled for relativistic heavy-ion collisions from the available experimental data at Brookhaven National Laboratory and CERN and also by the use of an event generator. Multiplicity fluctuations are sensitive to QCD phase transition and to the presence of critical point in the QCD phase diagram. In addition, multiplicity fluctuations provide baselines for other event-by-event measurements. Multiplicity fluctuation expressed in terms of the scaled variance of the multiplicity distribution is an intensive quantity, but is sensitive to the volume fluctuation of the system. The importance of the choice of narrow centrality bins and the corrections of centrality bin width effect for controlling volume fluctuations have been discussed. It is observed that the mean and width of the multiplicity distributions monotonically increase as a function of increasing centrality at all collision energies, whereas the multiplicity ...

  15. Fluctuations of conserved charges in relativistic heavy ion collisions: An introduction

    Science.gov (United States)

    Asakawa, Masayuki; Kitazawa, Masakiyo

    2016-09-01

    Bulk fluctuations of conserved charges measured by event-by-event analysis in relativistic heavy ion collisions are observables which are believed to carry significant amount of information on the hot medium created by the collisions. Active studies have been done recently experimentally, theoretically, and on the lattice. In particular, non-Gaussianity of the fluctuations has acquired much attention recently. In this review, we give a pedagogical introduction to these issues, and survey recent developments in this field of research. Starting from the definition of cumulants, basic concepts in fluctuation physics, such as thermal fluctuations in statistical mechanics and time evolution of fluctuations in diffusive systems, are described. Phenomena which are expected to occur in finite temperature and/or density QCD matter and their measurement by event-by-event analyses are also elucidated.

  16. Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

    Science.gov (United States)

    Kondo, K; Kanesue, T; Tamura, J; Okamura, M

    2010-02-01

    Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented. PMID:20192366

  17. Trace initial interaction from final state observable in relativistic heavy ion collisions

    CERN Document Server

    Wang, Meijuan; Wu, Yuanfang

    2008-01-01

    In order to trace the initial interaction in ultra-relativistic heavy ion collision in all azimuthal directions, two azimuthal multiplicity-correlation patterns -- neighboring and fixed-to-arbitrary angular-bin correlation patterns -- are suggested. From the simulation of Au + Au collisions at 200 GeV by using the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without string melting, we observe that the correlation patterns change gradually from out-of-plane preferential one to in-plane preferential one when the centrality of collision shifts from central to peripheral, meanwhile the anisotropic collective flow v_2 keeps positive in all cases. This regularity is found to be model and collision energy independent. The physics behind the two opposite trends of correlation patterns, in particular, the presence of out-of-plane correlation patterns at RHIC energy, are discussed.

  18. Fluctuations of conserved charges in relativistic heavy ion collisions: An introduction

    CERN Document Server

    Asakawa, Masayuki

    2015-01-01

    Bulk fluctuations of conserved charges measured by event-by-event analysis in relativistic heavy ion collisions are observables which are believed to carry significant information on the primordial thermodynamics of the hot medium created by the collisions. Active studies have been done recently experimentally, theoretically, and on the lattice. In particular, non-Gaussianity of the fluctuations aquires much attention recently. In this review, we give a pedagogical introduction to these physics, and overview recent developments in this field of research. Starting from the definition of cumulants, basic concepts in fluctuation physics, such as thermal fluctuations in statistical mechanics and time evolution of fluctuations in diffusive systems, are described. Physics which are expected to occur in the QCD phase diagram and their measurement by event-by-event analyses are also elucidated.

  19. A viscous blast-wave model for relativistic heavy-ion collisions

    CERN Document Server

    Jaiswal, Amaresh

    2015-01-01

    Using a viscosity-based survival scale for geometrical perturbations formed in the early stages of relativistic heavy-ion collisions, we model the radial flow velocity during freeze-out. Subsequently, we employ the Cooper-Frye freeze-out prescription, with first-order viscous corrections to the distribution function, to obtain the transverse momentum distribution of particle yields and flow harmonics. For initial eccentricities, we use the results of Monte Carlo Glauber model. We fix the blast-wave model parameters by fitting the transverse momentum spectra of identified particles at the Large Hadron Collider (LHC) and demonstrate that this leads to a fairly good agreement with transverse momentum distribution of elliptic and triangular flow for various centralities. Within this viscous blast-wave model, we estimate the shear viscosity to entropy density ratio $\\eta/s\\simeq 0.24$ at the LHC.

  20. Investigation of Nuclear Fragmentation in Relativistic Heavy Ion Collisions Using Plastic - Nuclear - Track Detectors

    CERN Multimedia

    2002-01-01

    In this experiment CR39 plastic nuclear track detectors will be used which are sensitive to detect relativistic nuclear fragments with charges Z@$>$5. They will be analyzed using an automatic track measuring system which was developed at the University of Siegen.\\\\ \\\\ This allows to measure large quantities of tracks in these passive detectors and to perform high statistics experiments. We intend to measure cross sections for the production of nuclear fragments from heavy ion beams at the SPS. \\\\ \\\\ The energy independence of the cross sections predicted by the idea of limiting fragmentation will be tested at high energies. In exposures with different targets we plan to analyze the factorization of the fragmentation cross sections into a target depending factor and a factor depending on the beam particle and the fragment. The cross sections for one proton remov Coulomb dissociation. \\\\ \\\\ We plan to investigate Coulomb dissociation for different targets and different energies. Fragment and projectile charges ...

  1. Hydrodynamics with chiral anomaly and charge separation in relativistic heavy ion collisions

    CERN Document Server

    Yin, Yi

    2015-01-01

    Matter with chiral fermions is microscopically described by theory with quantum anomaly and macroscopically described (at low energy) by anomalous hydrodynamics. For such systems in the presence of external magnetic field and chirality imbalance, a charge current is generated along the magnetic field direction --- a phenomenon known as the Chiral Magnetic Effect (CME). The quark-gluon plasma created in relativistic heavy ion collisions provides an (approximate) example, for which the CME predicts a charge separation perpendicular to the collisional reaction plane. Charge correlation measurements designed for the search of such signal have been done at RHIC and the LHC for which the interpretations, however, remain unclear due to contamination by background effects that are collective flow driven, theoretically poorly constrained, and experimentally hard to separate. Using anomalous (and viscous) hydrodynamic simulations, we make a first attempt at quantifying contributions to observed charge correlations from...

  2. Can van Hove singularities be observed in relativistic heavy-ion collisions?

    Indian Academy of Sciences (India)

    Munshi G Mustafa; Markus H Thoma

    2003-04-01

    Based on general arguments, the in-medium quark propagator in a quark–gluon plasma leads to a quark dispersion relation consisting of two branches, of which one exhibits a minimum at some finite momentum. This results in a vanishing group velocity for collective quark modes. Important quantities such as the production rate of low mass lepton pairs and mesonic correlators depend inversely on this group velocity. Therefore these quantities, which follow from self energy diagrams containing a quark loop, are strongly affected by van Hove singularities (peaks and gaps). If these sharp structures could be observed in relativistic heavy-ion collisions it would reveal the physical picture of the quark–gluon plasma (QGP) as a gas of quasiparticles.

  3. Study of relativistic heavy ion collisions and search for a quark-gluon plasma. Final report

    International Nuclear Information System (INIS)

    Results for (Lambda) production by gold beams on gold targets were analyzed and published. The author completed the analysis of the Si-Si and Si-Lead data from previous runs. The results have been published in a series of papers. Major components of the STAR detector for RHIC have been built and have arrived at BNL. The detector continues to evolve and work continues on developing programs for the detector and simulating events and physics results that will be seen by it. The move is underway from design to physical construction to test and commissioning and some of the detector is taking shape. Much of the effort in the past year has gone into refining the detector design, looking at possible triggers, and developing a software system for simulating and eventually analyzing events. Building, commissioning, and operating this detector (including the software) will be a major effort over the coming years. The author studied the E810 Si-Pb full field data for positive-negative track correlations. He estimated the number of excited nucleons (N*'s) and Deltas in their region of measurement. From the relative population of ground state nucleons (pn,n) and excited nucleons he determined the freeze-out temperature of the hot system created in a high energy, heavy ion collision. Prof. Kramer was involved in the overall program for E881 and primarily in the software development for STAR while Mr. Efstathiadis had concentrated on understanding the data, i.e. primarily developing Monte Carlo programs to gain insight into the mechanisms important in the collisions and corrections needed in the analysis. The latest versions of GEANT were used to simulate the E891 apparatus and special programs were developed to be able to easily input STAR detector geometries into GEANT

  4. SynapSense Wireless Environmental Monitoring System of the RHIC & ATLAS Computing Facility at BNL

    Science.gov (United States)

    Casella, K.; Garcia, E.; Hogue, R.; Hollowell, C.; Strecker-Kellogg, W.; Wong, A.; Zaytsev, A.

    2014-06-01

    RHIC & ATLAS Computing Facility (RACF) at BNL is a 15000 sq. ft. facility hosting the IT equipment of the BNL ATLAS WLCG Tier-1 site, offline farms for the STAR and PHENIX experiments operating at the Relativistic Heavy Ion Collider (RHIC), the BNL Cloud installation, various Open Science Grid (OSG) resources, and many other small physics research oriented IT installations. The facility originated in 1990 and grew steadily up to the present configuration with 4 physically isolated IT areas with the maximum rack capacity of about 1000 racks and the total peak power consumption of 1.5 MW. In June 2012 a project was initiated with the primary goal to replace several environmental monitoring systems deployed earlier within RACF with a single commercial hardware and software solution by SynapSense Corporation based on wireless sensor groups and proprietary SynapSense™ MapSense™ software that offers a unified solution for monitoring the temperature and humidity within the rack/CRAC units as well as pressure distribution underneath the raised floor across the entire facility. The deployment was completed successfully in 2013. The new system also supports a set of additional features such as capacity planning based on measurements of total heat load, power consumption monitoring and control, CRAC unit power consumption optimization based on feedback from the temperature measurements and overall power usage efficiency estimations that are not currently implemented within RACF but may be deployed in the future.

  5. Charmonium-Nucleon Interaction from Quenched Lattice QCD with Relativistic Heavy Quark Action

    Science.gov (United States)

    Kawanai, Taichi; Sasaki, Shoichi; Hatsuda, Tetsuo

    2009-10-01

    Low energy charmonium-nucleon interaction is of particular interest in this talk. A heavy quarkonium state like the charmonium does not share the same quark flavor with the nucleon so that cc-nucleon interaction might be described by the gluonic van der Waals interaction, which is weak but attractive. Therefore, the information of the strength of cc-nucleon interaction is vital for considering the possibility of the formation of charmonium bound to nuclei. We will present the preliminary results for the scattering length and the interaction range of charmonium-nucleon s-wave scattering from quenched lattice QCD. These low-energy quantities can provide useful constraints on the phenomenological cc-nucleon potential, which is required for precise prediction of the binding energy of nuclear-bound charmonium in exact few body calculations. Our simulations are performed at a lattice cutoff of 1/a=2.0 GeV with the nonperturbatively O(a) improved Wilson action for the light quark and a relativistic heavy quark action for the charm quark. A new attempt of calculating the cc-nucleon potential through the Bethe-Salpeter wave function will be also discussed.

  6. Asymptotic channels and gauge transformations of the time-dependent Dirac equation for extremely relativistic heavy-ion collisions

    CERN Document Server

    Wells, J C; Eichler, J

    1999-01-01

    We discuss the two-center, time-dependent Dirac equation describing the dynamics of an electron during a peripheral, relativistic heavy-ion collision at extreme energies. We derive a factored form, which is exact in the high-energy limit, for the asymptotic channel solutions of the Dirac equation, and elucidate their close connection with gauge transformations which transform the dynamics into a representation in which the interaction between the electron and a distant ion is of short range. We describe the implications of this relationship for solving the time-dependent Dirac equation for extremely relativistic collisions.

  7. Heavy-flavor production in heavy-ion collisions and implications for the properties of hot QCD matter

    CERN Document Server

    Averbeck, R

    2015-01-01

    Hadrons carrying open heavy flavor, i.e. single charm or bottom quarks, are among the key diagnostic tools available today for the hot and dense state of strongly interacting matter which is produced in collisions of heavy atomic nuclei at ultra-relativistic energies. First systematic heavy-flavor measurements in nucleus-nucleus collisions and the reference proton-proton system at Brookhaven National Laboratory's (BNL) Relativistic Heavy Ion Collider (RHIC) have led to tantalizing results. These studies are now continued and extended at RHIC and at CERN's Large Hadron Collider (LHC), where considerably higher collision energies are available. This review focuses on experimental results on open heavy-flavor observables at RHIC and the LHC published until July 2012. Yields of heavy-flavor hadrons and their decay products, their transverse momentum and rapidity distributions, as well as their azimuthal distributions with respect to the reaction plane in heavy-ion collisions are investigated. Various theoretical ...

  8. The discovery of nuclear compression phenomena in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    This article has attempted to review more than 15 years of research on shock compression phenomena, which is closely related to the goal of determining the nuclear EOS. Exciting progress has been made in this field over the last years and the fundamental physics of relativistic heavy ion-collisions has been well established. Overwhelming experimental evidence for the existence of shock compression has been extracted from the data. While early, inclusive measurements had been rather inconclusive, the advent of 4π-detectors like the GSI-LBL Plastic Ball had enabled the outstanding discovery of collective flow effects, as they were predicted by fluid-dynamical calculations. The particular case of conical Mach shock waves, anticipated for asymmetric collisions, has not been observed. What are the reasons? Surprisingly, the maximum energy of 2.1 GeV/nucleon for heavy ions at the BEVALAC had been found to be too low for Mach shock waves to occur. The small 20Ne-nucleus is stopped in the heavy Au target. A Mach cone, however, if it had developed in the early stage of the collision will be wiped out by thermal motion in the process of slowing the projectile down to rest. A comparison of the data with models hints towards a rather hard EOS, although a soft one cannot be excluded definitively. A quantitative extraction is aggravated by a number in-medium and final-state effects which influence the calculated observables in a similar fashion as different choices of an EOS. Thus, as of now, the precise knowledge of the EOS of hot and dense matter is still an open question and needs further investigation. (orig.)

  9. From SPS to RHIC: Maurice and the CERN heavy-ion programme

    OpenAIRE

    Heinz, Ulrich W.

    2008-01-01

    Maurice Jacob played a key role in bringing together different groups from the experimental and theoretical nuclear and particle physics communities to initiate an ultrarelativistic heavy-ion collision program at the CERN SPS, in order to search for the quark-gluon plasma. I review the history of this program from its beginnings to the time when the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) started operation. I close by providing a glimpse of the important...

  10. Thoughts on measuring particle's circular polarization variation with respect to the reaction plane in relativistic heavy-ion collisions

    CERN Document Server

    Tang, A H

    2016-01-01

    The EM field pattern created by spectators in relativistic heavy-ion collisions plants a seed of positive (negative) magnetic helicity in the hemisphere above (below) the reaction plane. Owing to the chiral anomaly, the magnetic helicity interacts with the fermionic helicity of the collision system, and causes photons emitted in upper- and lower-hemispheres to have different preferences in the circular polarization. In this paper, we lay down a procedure to measure the variation of the circular polarization w.r.t the reaction plane in relativistic heavy-ion collisions for massless photons, as well as similar polarization patterns for vector mesons decaying into two daughters. We propose to study the yield differentially and compare the yield between upper- and lower-hemispheres in order to identify and quantify such effects.

  11. Event-by-event analysis of ultra-relativistic heavy-ion collisions in smoothed particle hydrodynamics

    OpenAIRE

    Osada, T.; Aguiar, C. E.; Hama, Y.; Kodama, T.

    2001-01-01

    The method of smoothed particle hydrodynamics (SPH) is applied for ultra-relativistic heavy-ion collisions. The SPH method has several advantages in studying event-by-event fluctuations, which attract much attention in looking for quark gluon plasma (QGP) formation, because it gives a rather simple scheme for solving hydrodynamical equations. Using initial conditions for Au+Au collisions at RHIC energy produced by NeXus event generator, we solve the hydrodynamical equation in event-by-event b...

  12. The electron lens test bench for the relativistic heavy ion collider at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    To compensate for the beam–beam effects from the proton–proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for both the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an yttrium aluminum garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage

  13. Nuclear-breakup mechanisms in the interaction of relativistic projectiles with heavy targets

    International Nuclear Information System (INIS)

    The breakup of a Au nucleus under bombardment with relativistic p, α, and 20Ne has been investigated in an extensive, multi-detector study. The present discussion addresses some of the many aspects of the experimental results. A broad distribution of coincident fragment masses is observed, with the total fragment kinetic energy being higher than expected for a fission mechanism for total fragment mass less than or equal to 120. The formation of light fragments is shown to be inconsistent with a binary breakup mechanism, and a multi-fragment target breakup is suggested. In general, the results indicate a broad spectrum of violence in the collisions, from gentle, leading to the production of heavy spallation products and fission, to essentially explosive, leading to multi-fragment breakup into light mas products. These aspects of the reactions represent a late-stage breakup of the target residues and are positively correlated with the violence of the initial fast stage of the collision as measured by the charged particle multiplicity

  14. Temperature dependence of sound velocity and hydrodynamics of ultra-relativistic heavy-ion collisions

    CERN Document Server

    Chojnacki, M; Chojnacki, Mikolaj; Florkowski, Wojciech

    2007-01-01

    The effects of different forms of the sound-velocity function c_s(T) on the hydrodynamic evolution of matter created in the central region of ultra-relativistic heavy-ion collisions are studied. Above the critical temperature T_c we use the sound velocity function obtained from the recent lattice simulations of QCD, whereas below the critical temperature we use the hadron gas model. In the neighborhood of the critical temperature different interpolations between those two results are employed. They are characterized by the depth of the minimum of the function c_s(T) at T_c. We find that the presence of a distinct minimum of the sound velocity leads to a very long (exceeding 20 fm/c) evolution time of the system. Since such long evolution times are not compatible with the recent estimates based on the HBT interferometry, we conclude that the hydrodynamic description becomes adequate if the QCD cross-over phase transition renders the smooth temperature variations of the sound velocity, with a possible shallow m...

  15. A multiple sampling ionization chamber (MUSIC) for measuring the charge of relativistic heavy ions

    International Nuclear Information System (INIS)

    A large area (1 m x 2 m) multiple sampling ionization chamber (MUSIC) has been constructed and tested. The MUSIC detector makes multiple measurements of energy 'loss', dE/dx, for a relativistic heavy ion. Given the velocity, the charge of the ion can be extracted from the energy loss distributions. The widths of the distributions we observe are much narrower than predicted by Vavilov's theory for energy loss while agreeing well with the theory of Badhwar which deals with the energy deposited. The versatile design of MUSIC allows a variety of anode configurations which results in a large dynamic range of charge. In our tests to date we have observed charge resolutions of 0.25e fwhm for 727 MeV/nucleon 40Ar and 0.30e fwhm for 1.08 GeV/nucleon 139La and 139La fragments. Vertical position and multiple track determination are obtained by using time projection chamber electronics. Preliminary tests indicate that the position resolution is also very good with σ≅100 μm. (orig.)

  16. The electron lens test bench for the relativistic heavy ion collider at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X., E-mail: xgu@bnl.gov; Altinbas, F.Z.; Beebe, E.; Fischer, W.; Frak, B.M.; Gassner, D.M.; Hamdi, K.; Hock, J.; Hoff, L.; Kankiya, P.; Lambiase, R.; Luo, Y.; Mapes, M.; Mi, J.; Miller, T.; Montag, C.; Nemesure, S.; Okamura, M.; Olsen, R.H.; Pikin, A.I.; and others

    2014-04-11

    To compensate for the beam–beam effects from the proton–proton interactions at the two interaction points IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC), we are constructing two electron lenses (e-lenses) that we plan to install in the interaction region IR10. Before installing them, the electron gun, collector, instrumentation were tested and the electron beam properties were qualified on an electron lens test bench. We will present the test results and discuss our measurement of the electron beam current and of the electron gun perveance. We achieved a maximum current of 1 A with 5 kV energy for both the pulsed- and the DC-beam (which is a long turn-by-turn pulse beam). We measured beam transverse profiles with an yttrium aluminum garnet (YAG) screen and pinhole detector, and compared those to simulated beam profiles. Measurements of the pulsed electron beam stability were obtained by measuring the modulator voltage.

  17. Elliptic flow as a probe for $\\psi(2S)$ production mechanism in relativistic heavy ion collisions

    CERN Document Server

    Chen, Baoyi

    2016-01-01

    I discuss the elliptic flows of $\\psi(2S)$ with different production mechanisms in the middle $p_T$ bin in $\\sqrt{s_{NN}}=2.76$ TeV Pb-Pb collisions. If the final $\\psi(2S)$s are mainly from the recombination of uncorrelated charm and anticharm quarks at $T\\approx T_c$, charm and anticharm quarks will carry large collective flows of the bulk medium, which will be inherited to the regenerated $\\psi(2S)$s. This indicates a larger elliptic flow of $\\psi(2S)$ than that of $J/\\psi$ which can be regenerated at $T\\ge T_c$, $v_2^{\\psi(2S)}>v_2^{J/\\psi}$. However, if the final $\\psi(2S)$s are mainly from the transitions of $J/\\psi\\rightarrow \\psi(2S)$ caused by the color screening of QGP, its elliptic flow should be close to the elliptic flow of $J/\\psi$, $v_2^{\\psi(2S)}\\lesssim v_2^{J/\\psi}$. Therefore, $\\psi(2S)$ elliptic flow is a sensitive probe for its production mechanisms in relativistic heavy ion collisions.

  18. Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-09-09

    To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.

  19. Modeling and Analysis of Ultra-Relativistic Heavy-Ion Collisions. Final Report

    International Nuclear Information System (INIS)

    Hadronic, i.e. strongly interacting, matter is described by the theory of quantum chromodynamics (QCD). The basic constituents of QCD, quarks and gluons, are normally confined to hadrons, but it is believed that under extreme conditions, such as shortly after the creation of the universe, quarks and gluons can exist as independent particles in a new state of matter, called a quark-gluon plasma (QGP). Due to the rapid expansion of the universe, this plasma went through a phase transition to form hadrons - most importantly nucleons - which constitute the building blocks of matter as we know it today. The investigation of the QGP under laboratory conditions will yield important novel insights into the development of the early universe and the behavior of matter under extreme conditions. This study is presently the subject of the physics program of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. First data from the √sNN = 130 GeV and √sNN = 200 GeV Au+Au runs at RHIC have yielded many interesting and sometimes surprising results. While many theoretical predictions have been confirmed, some of the experimental results have brought surprises and indicate that RHIC is, indeed, probing a new physics regime of QCD matter.

  20. Fluctuations in charged particle multiplicities in relativistic heavy-ion collisions

    Science.gov (United States)

    Mukherjee, Maitreyee; Basu, Sumit; Choudhury, Subikash; Nayak, Tapan K.

    2016-08-01

    Multiplicity distributions of charged particles and their event-by-event fluctuations have been compiled for relativistic heavy-ion collisions from the available experimental data at Brookhaven National Laboratory and CERN and also by the use of an event generator. Multiplicity fluctuations are sensitive to QCD phase transition and to the presence of a critical point in the QCD phase diagram. In addition, multiplicity fluctuations provide baselines for other event-by-event measurements. Multiplicity fluctuation expressed in terms of the scaled variance of the multiplicity distribution is an intensive quantity, but is sensitive to the volume fluctuation of the system. The importance of the choice of narrow centrality bins and the corrections of the centrality bin-width effect for controlling volume fluctuations have been discussed. It is observed that the mean and width of the multiplicity distributions monotonically increase as functions of increasing centrality at all collision energies, whereas the multiplicity fluctuations show minimal variations with centrality. The beam-energy dependence shows that the multiplicity fluctuations have a slow rise at lower collision energies and remain constant at higher energies.

  1. Hadronic and partonic sources of direct photons in relativistic heavy-ion collisions

    CERN Document Server

    Linnyk, O; Steinert, T; Cassing, W; Bratkovskaya, E L

    2015-01-01

    The direct photon spectra and flow ($v_2$, $v_3$) in heavy-ion collisions at SPS, RHIC and LHC energies are investigated within a relativistic transport approach incorporating both hadronic and partonic phases -- the Parton-Hadron-String Dynamics (PHSD). In the present work, four extensions are introduced compared to our previous calculations: (i) going beyond the soft-photon approximation (SPA) in the calculation of the bremsstrahlung processes $meson+meson\\to meson+meson+\\gamma$, (ii) quantifying the suppression due to the Landau-Pomeranchuk-Migdal (LPM) coherence effect, (iii) adding the additional channels $V+N\\to N+\\gamma$ and $\\Delta\\to N+\\gamma$ and (iv) providing predictions for Pb+Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV. The first issue extends the applicability of the bremsstrahlung calculations to higher photon energies in order to understand the relevant sources in the region $p_T=0.5-1.5$~GeV, while the LPM correction turns out to be important for $p_T<0.4$~GeV in the partonic phase. The r...

  2. Multiple sampling ionization chamber (MUSIC) for measuring the charge of relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Christie, W.B.; Romero, J.L.; Brady, F.P.; Tull, C.E.; Castaneda, C.M.; Barasch, E.F.; Webb, M.L.; Drummond, J.R.; Crawford, H.J.; Flores, I.

    1987-04-01

    A large area (1 m x 2 m) multiple sampling ionization chamber (MUSIC) has been constructed and tested. The MUSIC detector makes multiple measurements of energy 'loss', dE/dx, for a relativistic heavy ion. Given the velocity, the charge of the ion can be extracted from the energy loss distributions. The widths of the distributions we observe are much narrower than predicted by Vavilov's theory for energy loss while agreeing well with the theory of Badhwar which deals with the energy deposited. The versatile design of MUSIC allows a variety of anode configurations which results in a large dynamic range of charge. In our tests to date we have observed charge resolutions of 0.25e fwhm for 727 MeV/nucleon /sup 40/Ar and 0.30e fwhm for 1.08 GeV/nucleon /sup 139/La and /sup 139/La fragments. Vertical position and multiple track determination are obtained by using time projection chamber electronics. Preliminary tests indicate that the position resolution is also very good with sigmaapprox. =100 ..mu..m.

  3. Bakamjian-Thomas relativistic quark models satisfy Bjorken-Uraltsev sum rules of the heavy quark limit of QCD

    CERN Document Server

    Yaouanc, A Le; Raynal, J -C

    2015-01-01

    We underline that the Bakamjian-Thomas relativistic quark model is the only known theoretical scheme, describing hadrons with a fixed number of constituents, that yields covariant Isgur-Wise functions and satisfies the whole tower of lowest moment sum rules of the heavy quark limit of QCD (Bjorken-Uraltsev sum rules). In the heavy quark limit, it has been demonstrated that a formalism, based on Lorentz group representations in a Hilbert space, implies this class of sum rules. On the other hand, it has been recently shown that a Lorentz group representation in a Hilbert space underlies the Bakamjian-Thomas class of relativistic quark models in the heavy quark limit. Therefore, due to completeness in this space, the model satisfies the whole tower of Bjorken-Uraltsev sum rules. To illustrate in practice this feature we provide some examples. In particular, we demonstrate explicitly Bjorken and Uraltsev sum rules within the Bakamjian-Thomas framework, and also an interesting sum rule that involves only heavy mes...

  4. Heavy Element Effects in the Diagonal Born-Oppenheimer Correction within a Relativistic Spin-Free Hamiltonian.

    Science.gov (United States)

    Imafuku, Yuji; Abe, Minori; Schmidt, Michael W; Hada, Masahiko

    2016-04-01

    Methodologies beyond the Born-Oppenheimer (BO) approximation are nowadays important to explain high precision spectroscopic measurements. Most previous evaluations of the BO correction are, however, focused on light-element molecules and based on a nonrelativistic Hamiltonian, so no information about the BO approximation (BOA) breakdown in heavy-element molecules is available. The present work is the first to investigate the BOA breakdown for the entire periodic table, by considering scalar relativistic effects in the Diagonal BO correction (DBOC). In closed shell atoms, the relativistic EDBOC scales as Z(1.25) and the nonrelativistic EDBOC scales as Z(1.17), where Z is the atomic number. Hence, we found that EDBOC becomes larger in heavy element atoms and molecules, and the relativistic EDBOC increases faster than nonrelativistic EDBOC. We have further investigated the DBOC effects on properties such as potential energy curves, spectroscopic parameters, and various energetic properties. The DBOC effects for these properties are mostly affected by the lightest atom in the molecule. Hence, in X2 or XAt molecule (X = H, Li, Na, K, Rb, and Cs) the effect of DBOC systematically decreases when X becomes heavier but in HX molecules, the effect of DBOC seems relatively similar among all the molecules. PMID:27003510

  5. Radiative electron capture studied in relativistic heavy-ion atom collisions

    International Nuclear Information System (INIS)

    The process of Radiative Electron Capture (REC) in relativistic collisions of high-Z ions with low-Z gaseous and solid targets is studied experimentally and theoretically. The observed X-ray spectra are analysed with respect to photon angular distributions as well as to total K-REC cross sections. The experimental results for angle-differential cross sections are well-reproduced by exact relativistic calculations which yield significant deviations from standard sin2θ distributions. Total cross sections for K-REC are shown to follow a simple scaling rule obtained from exact relativistic calculations as well as from a non-relativistic dipole approximation. The agreement between these different theoretical approaches must be regarded as fortuitous, but it lends support to the use of the non-relativistic approach for practical purposes. (orig.)

  6. Charged-particle multiplicity at mid-rapidity in Au–Au collisions at relativistic heavy-ion collider

    Indian Academy of Sciences (India)

    D Silvermyr

    2003-05-01

    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 $\\sqrt{S_{NN}}=130$ and 200 GeV at RHIC (relativistic heavy ion collider) have been measured with the PHENIX detector. The measurements were performed using sets of wire-chambers with pad readout in the two central PHENIX tracking arms. Each arm covers one quarter of the azimuth in the pseudorapidity interval || < 0.35. Data is presented and compared with results from proton–proton collisions and nucleus–nucleus collisions at lower energies. Extrapolations to LHC energies are discussed.

  7. Charged-particle multiplicity at mid-rapidity in Au-Au collisions at relativistic heavy-ion collider

    CERN Document Server

    Silvermyr, D

    2003-01-01

    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 root s//N//N = 130 and 200 GeV at RHIC (relativistic heavy ion collider) have been measured with the PHENIX detector. The measurements were performed using sets of wire-chambers with pad readout in the two central PHENIX tracking arms. Each arm covers one quarter of the azimuth in the pseudorapidity interval vertical bar eta vertical bar less than 0.35. Data is presented and compared with results from proton-proton collisions and nucleus-nucleus collisions at lower energies. Extrapolations to LHC energies are discussed. 16 Refs.

  8. Simulation of a relativistic heavy ions beam transport in the matter: contribution of the fragmentation process and biological implications

    International Nuclear Information System (INIS)

    The study of relativistic heavy ion collisions permit an approach of the properties of dense and not hadronic matter, and an analysis of the reaction mechanisms. Such studies are also interesting on the biological point of view, since there exist now well defined projects concerning the radiotherapy with high LET particles as neutrons, protons, heavy ions. It is thus necessary to have a good understanding of the processes which occur in the propagation of a relativistic heavy ion beam (E≥ 100 A.MeV) in matter. We have elaborated a three dimensional transport code, using a Monte Carlo method, in order to describe the propagation of Ne and Ar ions in water. Violent nuclear collisions giving fragmentation process have been taken into account by use of the FREESCO program. We have tested the validity of our transport model and we show an important change of the energy deposition at the vicinity of the Bragg peak; such a distortion, due mainly to fragmentation reactions, is of a great interest for biological applications. (author)

  9. Neighboring azimuthal bin-bin multiplicity correlation as a direct measure for the shear viscosity in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Neighboring azimuthal bin-bin multiplicity correlation is suggested to be a good measure for internal layer-to-layer interactions of the formed matter in relativistic heavy ion collisions. It is shown to be directly related to the shear viscosity of the formed matter. As an application of this method, the shear viscosity in the samples generated by a multi-phase transport model (AMPT) is estimated. The results are in qualitative agreement with the theoretical calculation from microscopic interactions, i.e., the larger the scattering cross section, the smaller the shear viscosity. (authors)

  10. Pion Transverse Momentum Spectrum, Elliptic Flow and Interferometry in the Granular Source Model in Ultra-Relativistic Heavy Ion Collisions

    OpenAIRE

    Yang, Jing; Ren, Yan-Yu(Department of Physics, Harbin Institute of Technology, Harbin, Heilongjiang 150006, China); Zhang, Wei-Ning

    2015-01-01

    We systematically investigate the pion transverse momentum spectrum, elliptic flow, and Hanbury-Brown-Twiss (HBT) interferometry in the granular source model of quark-gluon plasma droplets in ultra-relativistic heavy ion collisions. The granular source model can well reproduce the experimental results of the Au-Au collisions at $\\sqrt{s_{NN}}=$ 200 GeV and the Pb-Pb collisions at $\\sqrt{s_{NN}} =$ 2.76 TeV with different centralities. We examine the parameters of the granular source models wi...

  11. Pion Transverse Momentum Spectrum, Elliptic Flow and Interferometry in the Granular Source Model in Ultra-Relativistic Heavy Ion Collisions

    CERN Document Server

    Yang, Jing; Zhang, Wei-Ning

    2015-01-01

    We systematically investigate the pion transverse momentum spectrum, elliptic flow, and Hanbury-Brown-Twiss (HBT) interferometry in the granular source model of quark-gluon plasma droplets in ultra-relativistic heavy ion collisions. The granular source model can well reproduce the experimental results of the Au-Au collisions at $\\sqrt{s_{NN}}=$ 200 GeV and the Pb-Pb collisions at $\\sqrt{s_{NN}} =$ 2.76 TeV with different centralities. We examine the parameters of the granular source models with an uniform and Woods-Saxon initial energy distributions in a droplet. The parameters exhibit certain regularities for collision centrality and energy.

  12. Many-electron relativistic calculation and interpretation of atomic processes in time dependent heavy-ion scattering

    Science.gov (United States)

    Thies, B.; Sepp, W.-D.; Fricke, B.

    1989-07-01

    The time dependence of a heavy-ion-atom collision system is solved via a set of coupled channel equations using energy eigen-values and matrix elements from a self-consistent field relativistic molecular many-electron Dirac-Fock-Slater calculation. Within this independent particle model we give a full many-particle interpretation by performing a small number of single-particle calculations. First results for the P( b) curves for the Ne K-hole excitation for the systems F 8+-Ne and F 6+-Ne as examples are discussed.

  13. Ultra-relativistic heavy-ion physics with AFTER@LHC

    DEFF Research Database (Denmark)

    Rakotozafindrabe, A.; Arnaldi, R.; Brodsky, Stanley;

    2013-01-01

    We outline the opportunities for ultra-relativistic heavy–ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal.......We outline the opportunities for ultra-relativistic heavy–ion physics which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and ion LHC beams extracted by a bent crystal....

  14. Optical beam profile monitor and residual gas fluorescence at the relativistic heavy ion collider polarized hydrogen jet.

    Science.gov (United States)

    Tsang, T; Bellavia, S; Connolly, R; Gassner, D; Makdisi, Y; Russo, T; Thieberger, P; Trbojevic, D; Zelenski, A

    2008-10-01

    A gas fluorescence beam profile monitor has been implemented at the relativistic heavy ion collider (RHIC) using the polarized atomic hydrogen gas jet, which is part of the polarized proton polarimeter. RHIC proton beam profiles in the vertical plane of the accelerator are obtained as well as measurements of the width of the gas jet in the beam direction. For gold ion beams, the fluorescence cross section is sufficiently large so that profiles can be obtained from the residual gas alone, albeit with long light integration times. We estimate the fluorescence cross sections that were not known in this ultrarelativistic regime and calculate the beam emittance to provide an independent measurement of the RHIC beam. This optical beam diagnostic technique, utilizing the beam induced fluorescence from injected or residual gas, offers a noninvasive particle beam characterization and provides visual observation of proton and heavy ion beams. PMID:19044742

  15. Two-pion interferometry at small relative momentum for pion sources with transverse and longitudinal expansions in relativistic heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    Chen Xiao-Fan; Yang Xue-Dong; Hah Ling

    2004-01-01

    A two-pion correlation function at small relative momentum for pion sources with transverse and longitudinal expansions in relativistic heavy ion collisions is obtained using two-pion interferometry at small relative momentum,and the relations between the real and apparent parameters of the pion source are given. The relations can be used to extract both the temperature and the transverse and longitudinal expansion velocities of pion sources and to verify the correctness of relativistic transformation T' = T√1- v2 of temperature in relativistic statistical mechanics and thermodynamics.

  16. Properties of hot and dense matter created in relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Arsene, Ionut Cristian

    2009-07-01

    In this thesis we tried to characterize a few aspects of the rich field of relativistic heavy ion collisions at intermediate and high energies. In chapter 2 we used two different microscopic string models, UrQMD and QGSM, to study the formation and evolution of the locally equilibrated matter in the central zone of heavy ion collisions at energies spanning from sq root sNN approx 4 GeV up to 17.3 GeV. The calculations were performed both in the cubic central cell of fixed volume V = 5 centre dot 5 centre dot 5 fm3 and for the instantly expanding volume of homogeneous energy density. To decide whether or not equilibrium is reached we used a traditional approach based on the fulfillment of the conditions of kinetic, thermal and chemical equilibrium. Both models favor the formation of equilibrated matter for a period of about 10 fm/c in which the matter expands isentropically with constant entropy per baryon. The square of the speed of sound c{sub s}2 has been found to vary in UrQMD from 0.13 at AGS to 0.15 at SPS energies and in QGSM from 0.11 at AGS to 0.15 at SPS. In both models the rise in c{sub s}2 slows down at sq rootsNN approx 9 GeV. Chapter 3 describes the HYDJET++ model as a superposition of the soft, hydrotype state and the hard state resulting from multi-parton fragmentation. Both states are treated independently. The hard part is an NN collision generator called PYQUEN which modifies the 'standard' jet event obtained with the PYTHIA generator and includes radiative and collisional energy loss for partons. Initial state effects like shadowing are included also. The soft part is the thermal hadronic state generated on the chemical and thermal freeze-out hypersurfaces obtained from the parametrization of relativistic hydrodynamics. We found that this model gives a good description of soft observables at top RHIC energy, like the p{sub T} spectrum, elliptic flow and HBT correlations. The hard part of the model describes well the high-p{sub T

  17. Properties of hot and dense matter created in relativistic heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Arsene, Ionut Cristian

    2009-07-01

    In this thesis we tried to characterize a few aspects of the rich field of relativistic heavy ion collisions at intermediate and high energies. In chapter 2 we used two different microscopic string models, UrQMD and QGSM, to study the formation and evolution of the locally equilibrated matter in the central zone of heavy ion collisions at energies spanning from sq root sNN approx 4 GeV up to 17.3 GeV. The calculations were performed both in the cubic central cell of fixed volume V = 5 centre dot 5 centre dot 5 fm3 and for the instantly expanding volume of homogeneous energy density. To decide whether or not equilibrium is reached we used a traditional approach based on the fulfillment of the conditions of kinetic, thermal and chemical equilibrium. Both models favor the formation of equilibrated matter for a period of about 10 fm/c in which the matter expands isentropically with constant entropy per baryon. The square of the speed of sound c{sub s}2 has been found to vary in UrQMD from 0.13 at AGS to 0.15 at SPS energies and in QGSM from 0.11 at AGS to 0.15 at SPS. In both models the rise in c{sub s}2 slows down at sq rootsNN approx 9 GeV. Chapter 3 describes the HYDJET++ model as a superposition of the soft, hydrotype state and the hard state resulting from multi-parton fragmentation. Both states are treated independently. The hard part is an NN collision generator called PYQUEN which modifies the 'standard' jet event obtained with the PYTHIA generator and includes radiative and collisional energy loss for partons. Initial state effects like shadowing are included also. The soft part is the thermal hadronic state generated on the chemical and thermal freeze-out hypersurfaces obtained from the parametrization of relativistic hydrodynamics. We found that this model gives a good description of soft observables at top RHIC energy, like the p{sub T} spectrum, elliptic flow and HBT correlations. The hard part of the model describes well the high-p{sub T

  18. Single electron attachment and stripping cross sections for relativistic heavy ions

    International Nuclear Information System (INIS)

    The results of a Bevalac experiment to measure the single electron attachment and stripping cross sections for relativistic (0.5 1, and fully stripped, N0, ion beams emerging from the targets. Separate counters measured the number of ions in each charge state. The ratios N1/N0 for different target thicknesses were fit to a simple growth curve to yield electron attachment and stripping cross sections. The data are compared to relativistic extrapolations of available theories. Clear evidence for two separate attachment processes, radiative and non-radiative, is found. Data are compared to a recently improved formulation for the stripping cross sections

  19. Non-relativistic leptogenesis

    OpenAIRE

    Bödeker, Dietrich; Wörmann, Mirco(Fakultät für Physik, Universität Bielefeld, Bielefeld, D-33615 Germany)

    2013-01-01

    In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe. We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections. We determine the leading order coefficients in these equations, and the first relativistic corrections. The non-relativistic appr...

  20. Applications of the lahet simulation code to relativistic heavy ion detectors

    Energy Technology Data Exchange (ETDEWEB)

    Waters, L.; Gavron, A. [Los Alamos National Lab., NM (United States)

    1991-12-31

    The Los Alamos High Energy Transport (LAHET) simulation code has been applied to test beam data from the lead/scintillator Participant Calorimeter of BNL AGS experiment E814. The LAHET code treats hadronic interactions with the LANL version of the Oak Ridge code HETC. LAHET has now been expanded to handle hadrons with kinetic energies greater than 5 GeV with the FLUKA code, while HETC is used exclusively below 2.0 GeV. FLUKA is phased in linearly between 2.0 and 5.0 GeV. Transport of electrons and photons is done with EGS4, and an interface to the Los Alamos HMCNP3B library based code is provided to analyze neutrons with kinetic energies less than 20 MeV. Excellent agreement is found between the test data and simulation, and results for 2.46 GeV/c protons and pions are illustrated in this article.

  1. Radiative Energy Loss of Heavy Quark and Dead Cone Effect in Ultra-relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    XIANG Wen-Chang; DING Heng-Tong; ZHOU Dai-Cui

    2005-01-01

    @@ The lowest-order heavy quark radiative energy loss has been analysed to quantify the dead cone effect. The medium-induced gluon radiation is found to fill the dead cone, it is reduced at large gluon energies compared to the radiation of light quarks. We calculate the radiative energy loss of heavy quarks in the condition of dead cone effect. It is found that the radiative energy loss with dead cone effect is smaller than that without the dead cone effect.

  2. Modelling and measurement of jet quenching in relativistic heavy-ion collisions at the LHC

    NARCIS (Netherlands)

    Verweij, M.

    2013-01-01

    In relativistic collisions between nuclei, the creation of a strongly interacting medium, called the Quark Gluon Plasma (QGP), is expected. It is expected that such a medium also existed in the early universe just after the Big Bang. The phase transition of interest is where the dense medium of free

  3. Mössbauer spectroscopy for heavy elements: a relativistic benchmark study of mercury

    DEFF Research Database (Denmark)

    Knecht, Stefan; Fux, Samuel; van Meer, Robert;

    2011-01-01

    The electrostatic contribution to the Mössbauer isomer shift of mercury for the series HgFn (n = 1, 2; 4) with respect to the neutral atom has been investigated in the framework of 4- and 2-component relativistic theory. Replacing the integration of the electron density over the nuclear volume by...

  4. Search for electron-positron pair production by non-relativistic heavy charged particles

    International Nuclear Information System (INIS)

    The creation of e-e+ pairs by protons and He ions in the energy range between 1.0 and 2.5 MeV has been investigated. At higher bombarding energies the measured yields deviate considerably from the values calculated numerically on the basis of the non-relativistic approximation of Heitler and Nordheim. (orig.)

  5. Ab initio effective core potentials including relativistic effects and their application to the electronic structure calculations of heavy atoms and molecules

    International Nuclear Information System (INIS)

    The effects of the 4f shell of electrons and the relativity of valence electrons are compared. The effect of 4f shell (lanthanide contraction) is estimated from the numerical Hartree-Fock (HF) calculations of pseudo-atoms corresponding to Hf, Re, Au, Hg, Tl, Pb and Bi without 4f electrons and with atomic numbers reduced by 14. The relativistic effect estimated from the numerical Dirac-Hartree-Fock (DHF) calculations of those atoms is comparable in the magnitude with that of the 4f shell of electrons. Both are larger for 6s than for 5d or 6p electrons. The various relativistic effects on valence electrons are discussed in detail to determine the proper level of the approximation for the valence electron calculations of systems with heavy elements. An effective core potential system has been developed for heavy atoms in which relativistic effects are included in the effective potentials

  6. Ab initio effective core potentials including relativistic effects and their application to the electronic structure calculations of heavy atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.S.

    1977-11-01

    The effects of the 4f shell of electrons and the relativity of valence electrons are compared. The effect of 4f shell (lanthanide contraction) is estimated from the numerical Hartree-Fock (HF) calculations of pseudo-atoms corresponding to Hf, Re, Au, Hg, Tl, Pb and Bi without 4f electrons and with atomic numbers reduced by 14. The relativistic effect estimated from the numerical Dirac-Hartree-Fock (DHF) calculations of those atoms is comparable in the magnitude with that of the 4f shell of electrons. Both are larger for 6s than for 5d or 6p electrons. The various relativistic effects on valence electrons are discussed in detail to determine the proper level of the approximation for the valence electron calculations of systems with heavy elements. An effective core potential system has been developed for heavy atoms in which relativistic effects are included in the effective potentials.

  7. High Baryon Densities in Heavy Ion Collisions at Energies Attainable at the Relativistic Heavy Ion Collider and the Large Hadron Collider

    CERN Document Server

    Li, Ming

    2016-01-01

    In very high energy collisions nuclei are practically tranparent to each other but produce very hot, nearly baryon-free, matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei at the highest energy attainable at the Relativistic Heavy Ion Collider, for example, we find baryon densities more than ten times that of atomic nuclei over a large volume.

  8. Vorticity in heavy-ion collisions

    Science.gov (United States)

    Deng, Wei-Tian; Huang, Xu-Guang

    2016-06-01

    We study the event-by-event generation of flow vorticity in the BNL Relativistic Heavy Ion Collider Au +Au collisions and CERN Large Hadron Collider Pb +Pb collisions by using the hijing model. Different definitions of the vorticity field and velocity field are considered. A variety of properties of the vorticity are explored, including the impact parameter dependence, the collision energy dependence, the spatial distribution, the event-by-event fluctuation of the magnitude and azimuthal direction, and the time evolution. In addition, the spatial distribution of the flow helicity is also studied.

  9. Femtoscopic signatures of collective behavior as a probe of the thermal nature of relativistic heavy ion collisions

    CERN Document Server

    Kisiel, Adam

    2009-01-01

    Femtoscopy measures space-time characteristics of the particle emitting source created in relativistic heavy-ion collisions. It is argued that collective behavior of matter (radial flow) produces specific femtoscopic signatures. The one that is best known, the m_T dependence of the pion ``HBT radii'', can be explained by the alternative scenario of temperature gradients in an initial state thermal model. We identify others that can invalidate such alternatives, such as non-identical particle correlations and m_T scaling for particles of higher mass. Studies with a simple rescattering code show that as the interaction cross-section is increased the system develops collective behavior and becomes more thermalized at the same time, the two effects being the natural consequence of increased number of particle rescatterings. Repeating calculations with a more realistic rescattering model confirmed all of these conclusions and provided deeper insight into the mechanisms of collectivity buildup, showing a preference...

  10. Scaling of fluctuations in pp and pA collisions, and eccentricities in relativistic heavy-ion collisions

    Science.gov (United States)

    Dumitru, Adrian; Nara, Yasushi

    2012-03-01

    Multiplicity fluctuations at midrapidity in pp collisions at high energies are described by a negative binomial distribution and exhibit approximate Koba-Nielsen-Olesen (KNO) scaling. We find that these KNO fluctuations are important also for reproducing the multiplicity distribution in d+Au collisions observed at the Relativistic Heavy-Ion Collider (RHIC), adding to the Glauber fluctuations of the number of binary collisions or participants. We predict that the multiplicity distribution in p+Pb collisions at the Large Hadron Collider (LHC) also deviates little from the KNO scaling function. Finally, we analyze various moments of the eccentricity of the collision zone in A+A collisions at RHIC and LHC and find that particle production fluctuations increase fluctuation dominated moments such as the triangularity ɛ3 substantially.

  11. Heavy flavor electron RAA and υ2 in event-by-event relativistic hydrodynamics

    Science.gov (United States)

    Prado, Caio A. G.; Cosentino, Mauro R.; Munhoz, Marcelo G.; Noronha, Jorge; Suaide, Alexandre A. P.

    2016-04-01

    In this work we investigate how event-by-event hydrodynamics fluctuations affect the nuclear suppression factor and elliptic flow of heavy flavor mesons and non-photonic electrons. We use a 2D+1 Lagrangian ideal hydrodynamic code [1, 2] on an event-by-event basis in order to compute local temperature and flow profiles. Using a strong coupling inspired energy loss parametrization [3] on top of the evolving space-time energy density distributions we are able to propagate the heavy quarks inside the medium until the freeze-out temperature is reached and a Pythia [4] modeling of hadronization takes place. The resulting D0 and heavy-flavor electron yield is compared with recent experimental data for R AA and υ 2 from the STAR and PHENIX collaborations [5-7]. In addition we present preditions for the higher order Fourier harmonic coefficients υ3(pt) of heavy-flavor electrons at Rhic’s collisions.

  12. Evidence for creation of strong electromagnetic fields in relativistic heavy-ion collisions

    CERN Document Server

    Toneev, V; Voronyuk, V

    2016-01-01

    It is proposed to identify a strong electric field created during relativistic collisions of asymmetric nuclei via observation of pseudorapidity and transverse momentum distributions of hadrons with the same mass but opposite charges. The detailed calculation results for the directed flow within the Parton-Hadron String Dynamics model are given for Cu-Au interactions at the NICA collision energies of $\\sqrt{s_{NN}}=9$ and $5$ GeV. The separation effect is observable at 9 GeV as clearly as at 200 GeV

  13. Evidence for creation of strong electromagnetic fields in relativistic heavy-ion collisions

    Science.gov (United States)

    Toneev, V.; Rogachevsky, O.; Voronyuk, V.

    2016-08-01

    It is proposed to identify the strong electric field created during relativistic collisions of asymmetric nuclei via observation of pseudorapidity and transverse-momentum distributions of hadrons with the same mass but opposite charges. The detailed calculation results for the directed flow within the Parton-Hadron String Dynamics model are given for Cu-Au interactions at the NICA collision energies of √{s_{NN}} = 9 and 5 GeV. The separation effect is observable at 9GeV as clearly as at 200 GeV.

  14. A multiple sampling proportional counter for particle identification of relativistic heavy ions

    International Nuclear Information System (INIS)

    A multiple sampling dE/dx counter using a multiwire proportional chamber equipped with catbode pads was constructed for the multiple detection of dE/dx values along a particle trajectory. For low-energy particles this counter was proved to be useful as a Bragg-curve detector. At relativistic energies around E=14.6 GeV/nucleon good particle identification was obtained by cathode pad signals as well as anode signals for the range of projectile fragments from Z=1 (minimum ionization) up to a beam charge of Z=14. (orig.)

  15. Perturbative QCD as a probe of hadron structure: Volume 2. Proceedings of RIKEN BNL Research Center workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The workshop brought together about thirty invited participants from around the world, and an almost equal number of Brookhaven users and staff, to discuss recent developments and future prospects for hadronic strong interaction studies at high energy, particularly relating to the RHIC project at Brookhaven. RIKEN and Brookhaven have long traditions in and commitments to the study of the strong interactions, and the advent of the RHIC collider will open new opportunities both for relativistic heavy ion and polarized proton-proton studies. Activities at the RIKEN BNL Research Center are intended to focus on physics opportunities stimulated by this new facility. Thus, one of the purposes of the center is to provide a forum where workers in the field can gather to share and develop their ideas in a stimulating environment. The purpose of the workshop was both to delineate theoretical problems and stimulate collaborations to address them. The workshop focused primarily, but not exclusively, on spin and small-x physics.

  16. Excited-state evolution probed by convoy-electron emission in relativistic heavy-ion collisions

    Science.gov (United States)

    Takabayashi, Y.; Ito, T.; Azuma, T.; Komaki, K.; Yamazaki, Y.; Tawara, H.; Takada, E.; Murakami, T.; Seliger, M.; Tökési, K.; O. Reinhold, C.; Burgdörfer, J.

    2003-10-01

    We present a joint experimental and theoretical study of convoy-electron emission resulting from highly-charged-ion transport through carbon foils at moderately relativistic speeds. Energy spectra of electrons ejected at 0° have been measured for 390 MeV/u hydrogen-like Ar17+ ions and 460 MeV/u (β=v/c=0.74,γ=1.49) Fe25+ (1s), Fe24+ (1s2), and Fe23+ (1s22s) incident on carbon foils with thicknesses from 25 to 8700 μg/cm2. Due to this unprecedented wide range of thicknesses, the sequential excitation and ionization of initially deeply bound electrons to highly excited states and continuum states can be followed in considerable detail. The analysis of the spectra is aided by simulations based on the classical transport theory which has been extended to relativistic energies and to multielectron projectiles. The motion of the projectile electron inside the solid target is calculated taking into account the Coulomb potential of the projectile ion and the multiple stochastic collisions with target cores and target electrons. Different phases of the convoy-electron emissions can be disentangled: direct ejection to the continuum, the transient buildup of an excited-state wave packet followed by ionization, and postionization modification of the continuum spectrum. We find good agreement between experiment and simulation for the evolution of charge states and the emission spectrum.

  17. Mean-field approach in the multi-component gas of interacting particles applied to relativistic heavy-ion collisions

    CERN Document Server

    Anchishkin, D

    2014-01-01

    Generalized mean-field approach for thermodynamic description of relativistic single- and multi-component gas in the grand canonical ensemble is formulated. In the framework of the proposed approach different phenomenological excluded-volume procedures are presented and compared to the existing ones. The mean-field approach is then used to effectively include hard-core repulsion in hadron-resonance gas model for description of chemical freeze-out in heavy-ion collisions. We calculate the collision energy dependence of several quantities for different values of hard-core hadron radius and for different excluded-volume procedures such as van der Waals and Carnahan-Starling models. It is shown that a choice of the excluded-volume model becomes important for large particle densities, and for large enough values of hadron radii ($r\\gtrsim0.9$ fm) there can be a sizable difference between different excluded-volume procedures used to describe the chemical freeze-out in heavy-ion collisions.

  18. Mean-field approach in the multi-component gas of interacting particles applied to relativistic heavy-ion collisions

    Science.gov (United States)

    Anchishkin, D.; Vovchenko, V.

    2015-10-01

    A generalized mean-field approach for the thermodynamic description of relativistic single- and multi-component gas in the grand canonical ensemble is formulated. In the framework of the proposed approach, different phenomenological excluded-volume procedures are presented and compared to the existing ones. The mean-field approach is then used to effectively include hard-core repulsion in hadron-resonance gas model for description of chemical freeze-out in heavy-ion collisions. We calculate the collision energy dependence of several quantities for different values of hard-core hadron radius and for different excluded-volume procedures such as the van der Waals and Carnahan-Starling models. It is shown that a choice of the excluded-volume model becomes important for large particle densities. For large enough values of hadron radii (r≳ 0.9 fm) there can be a sizable difference between different excluded-volume procedures used to describe the chemical freeze-out in heavy-ion collisions. At the same time, for the smaller and more commonly used values of hard-core hadron radii (r≲ 0.5 fm), the precision of the van der Waals excluded-volume procedure is shown to be sufficient.

  19. Study of the energetic proton production in relativistic heavy ions Ne + nuclei collisions, using Diogene detector. Hadronic matter temperature

    International Nuclear Information System (INIS)

    The study of the proton's production differential cross sections, in the collision of relativistic heavy ions, allows to obtain the nuclear-matter temperature and gives information about the nucleons large burst pulses in the nucleus. The chosen thermodynamic model is a generalized approach of the R. Hagedorn model, applied to heavy ions collisions: the nuclear matter is divided in volume elements δV assumed to be in thermal and chemical equilibrium and emitting particles and fragments isotropically, inside their own system. The applied nuclear-matter velocity distribution depended only on the impact parameter and on the relationship between the chemical potential and the temperature. The predictions of this thermodynamic model were compared to the Saturne experimental results, using Diogene detector. The obtained temperature values are similar to those given by D. Hahn and H. Stoker. The proton production cross sections were measured for backward emitting angles. A relationship between the cross sections and the burst pulse distribution in the nuclei was settled

  20. Hunting down the quark-gluon plasma in relativistic heavy-ion collisions

    OpenAIRE

    Heinz, Ulrich

    1999-01-01

    The present status of the heavy-ion program to search for quark-gluon plasma is reviewed. The goal of this program is to recreate the Big Bang in the laboratory, by generating small chunks of exploding quark-gluon plasma (``The Little Bang''). I argue that the analogues of the three pillars of Big Bang Theory (Hubble flow, microwave background radiation, and primordial nucleosynthesis) have now been firmly established in heavy-ion collisions at SPS energies: there is convincing evidence for s...

  1. Hydrodynamics with spontaneous symmetry breaking application to relativistic heavy ion collisions

    CERN Document Server

    Lallouet, Y; Pujol, C

    2003-01-01

    In this paper we apply hydrodynamics for systems with continuous broken symmetries to heavy ion collisions in the framework of (1+1) dimensional Bjorken model. The temperature profile with respect to proper time determined in that context is compared with the one obtained when M\\"{u}ller-Israel-Stewart second order theory of dissipation is included on top of standard hydrodynamics.

  2. Analysis of angular distribution of fragments in relativistic heavy-ion collisions by quantum molecular dynamics

    Directory of Open Access Journals (Sweden)

    Ogawa Tatsuhiko

    2016-01-01

    Full Text Available To predict angular distribution of fragments produced in nucleusnucleus collisions, JAERI quantum molecular dynamics model (JQMD was improved. Because JQMD underestimated fragments in the forward angle, which were mainly produced by peripheral collisions, JQMD was revised so as to simulate peripheral collisions accurately. Density-dependent in-medium effect and relativistic effect on nucleonnucleon interactions were incorporated for this purpose. The revised version of JQMD coupled with a statistical decay model was used to calculate differential fragment production cross sections measured in earlier studies. Comparison of the measured data and calculation by the revised and old JQMD showed that the revised JQMD can predict fragment angular distribution better than old JQMD. Particularly, agreement of fragment yield in the forward angle is substantially improved.

  3. Double lepton pair production with electron capture in relativistic heavy--ion collisions

    CERN Document Server

    Artemyev, A N; Surzhykov, A

    2014-01-01

    We present a theoretical study of a double lepton pair production in ultra--relativistic collision between two bare ions. Special emphasis is placed to processes in which creation of (at least one) $e^+ e^-$ pair is accompanied by the capture of an electron into a bound ionic state. To evaluate the probability and cross section of these processes we employ two approaches based on (i) the first--order perturbation theory and multipole expansion of Dirac wavefunctions, and (ii) the equivalent photon approximation. With the help of such approaches, detailed calculations are made for the creation of two bound--free $e^+ e^-$ pairs as well as of bound--free $e^+ e^-$ and free--free $\\mu^+ \\mu^-$ pairs in collisions of bare lead ions Pb$^{82+}$. The results of the calculations indicate that observation of the double lepton processes may become feasible at the LHC facility.

  4. Relativistic theory for radiative forward electron emission in heavy ion-atom encounters

    Science.gov (United States)

    Jakubaßa-Amundsen, Doris; Müller, Robert; Surzhykov, Andrey; Yerokhin, Vladimir

    2014-12-01

    The forward electron emission with simultaneous photon production during the scattering of relativistic, highly stripped projectiles from light target atoms is calculated within the Dirac theory. The method of calculation is a simplification of the impulse approximation and is based on the relation of the cross section for radiative capture to continuum of loosely bound electrons to the frame-transformed electron bremsstrahlung cross section. It is demonstrated that such an approximation is well justified in a large region of energies and photon emission angles, with the exception of the extreme forward and backward emission and the soft-photon energy limit. The cusp spectrum and the corresponding angular distribution are compared to recent experimental data for the collision system 90.38 MeV/amu U88+ + N2.

  5. Multibin correlations in a superposition approach to relativistic heavy-ion collisions

    CERN Document Server

    Olszewski, Adam

    2015-01-01

    Analysis of correlation of multiplicities between various rapidity bins is carried out in the framework of a superposition approach consisting of three phases of the ultra-relativistic nuclear collision: early partonic phase, intermediate collective evolution, and statistical hadronization. Simple relations between the moments of produced hadrons and the moments of the sources produced in the initial partonic phase are presented. They involve only a few effective parameters describing the of microscopic dynamics of the system. We illustrate the practicality of the approach with the Glauber model simulations. Our study carries direct relevance for the interpretation of the upcoming results for the multibin multiplicity correlations from the LHC, which will help in an assessment of the correlation features of the state formed in the earliest stage of the reaction.

  6. Heavy Ion Physics at Low, Intermediate and Relativistic Energies Using 4PI Detectors - Proceedings of the International Research Workshop

    Science.gov (United States)

    Petrovici, M.; Sandulescu, A.; Pelte, D.; Stöcker, H.; Randrup, J.

    1997-10-01

    Energies * Production and Propagation of Neutral Mesons at Relativistic Energies * Bose-Einstein Correlations of Pion Wavepackets * Freeze-Out Conditions in Heavy Ion Collisions from 1 to 2 AGeV * Kaon and Pion Production in Nuclear Collisions * Strangeness Production and Propagation in Relativistic Heavy Ion Collisions * Studies of Meson Production at SIS Energies * Particle Production from SIS to SPS Energies * Correlations in the Vacuum * Strangeness Enhancement in Proton-Nucleus and Nucleus-Nucleus Interactions at SPS Energies * The ALICE Detector at the CERN LHC * Charge Ratio of Cosmic Rays Muons Measured by Their Decay with a Compact Detector Device * Current Interests in Cosmic Ray Research * Workshop Poster * Workshop Program * Participants * Sponsors

  7. Flow probe of symmetry energy in relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Flow observables in heavy-ion reactions at incident energies up to about 1GeV per nucleon have been shown to be very useful for investigating the reaction dynamics and for determining the parameters of reaction models based on transport theory. In particular, the elliptic flow in collisions of neutron-rich heavy-ion systems emerges as an observable sensitive to the strength of the symmetry energy at supra-saturation densities. The comparison of ratios or differences of neutron and proton flows or neutron and hydrogen flows with predictions of transport models favors an approximately linear density dependence, consistent with ab initio nuclear-matter theories. Extensive parameter searches have shown that the model dependence is comparable to the uncertainties of existing experimental data. Comprehensive new flow data of high accuracy, partly also through providing stronger constraints on model parameters, can thus be expected to improve our knowledge of the equation of state of asymmetric nuclear matter. (orig.)

  8. Diagonal and off-diagonal susceptibilities of conserved quantities in relativistic heavy-ion collisions

    CERN Document Server

    Chatterjee, Arghya; Nayak, Tapan K; Sahoo, Nihar Ranjan

    2016-01-01

    Susceptibilities of conserved quantities, such as baryon number, strangeness and electric charge are sensitive to the onset of quantum chromodynamics (QCD) phase transition and are expected to provide information on the matter produced in heavy-ion collision experiments. A comprehensive study of the second-order diagonal susceptibilities and cross correlations has been made within a thermal model approach of the hadron resonance gas (HRG) model as well as with a hadronic transport model, UrQMD. We perform a detailed analysis of the effect of detector acceptances and choice of particle species in the experimental measurements of the susceptibilities for heavy-ion collisions corresponding to \\sNN = 4 GeV to 200 GeV. The transverse momentum cutoff dependence of suitably normalised susceptibilities are proposed as useful observables to probe the properties of the medium at freezeout.

  9. Improved calculation of total cross section for pair production by relativistic heavy ions

    Science.gov (United States)

    Eby, P. B.

    1989-01-01

    A calculation of the total cross section for direct electron-positron pair production by heavy ions is described. It combines the use of the Weizsaecker-Williams method for low-energy transfers and existing calculations for high-energy transfers. Higher-order corrections to the total cross section are calculated based on the Weizsaecher-Williams method and existing results for pair production by photons.

  10. Relativistic quantum dynamics in strong fields: Photon emission from heavy, few-electron ions

    OpenAIRE

    Fritzsche, Sephan; Indelicato, Paul; Stöhlker, Thomas

    2004-01-01

    Version 18/11/04 Recent progress in the study of the photon emission from highly-charged heavy ions is reviewed. These investigations show that high-$Z$ ions provide a unique tool for improving the understanding of the electron-electron and electron-photon interaction in the presence of strong fields. Apart from the bound-state transitions, which are accurately described in the framework of Quantum Electrodynamics, much information has been obtained also from the radiative capture of (quas...

  11. Searching for quark matter with dileptons and photons: From SPS to relativistic heavy-ion collider

    Indian Academy of Sciences (India)

    Itzhak Tserruya

    2001-08-01

    The heavy-ion programme at the CERN SPS, which started back in ’86, has produced a wealth of very interesting and intriguing results in the quest for the quark-gluon plasma. The highlights of the programme on dilepton and direct photon measurements are reviewed emphasizing the most recent results obtained in Pb–Pb collisions at 158 A GeV. Prospects from RHIC are discussed.

  12. Size of the thermal source in relativistic heavy-ion collisions

    OpenAIRE

    Bozek, Piotr

    2005-01-01

    The dependence of the size of the thermal source on the centrality in ultrarelativistic heavy-ion collisions is studied. The interaction region consists of a well defined thermalized core, and of an outer mantle where the production scales with the number of participants. The thermal source builds up in the region with the largest density of participants in the transverse plane. Particle production in the thermalized core is enhanced in comparison to the wounded nucleon model. The change of t...

  13. Inner-shell ionization of heavy atoms by slow ions. A study of electronic relativistic effects and projectile Coulomb deflection in the Semiclassical Approximation

    International Nuclear Information System (INIS)

    Several investigations have been made on K and L shell ionization of the heavy collision partner in slow asymmetric collisions based on the SCA. The use of the SCA can only be defended for slow collisions if the projectile has a charge much less than the target. Thus this approximation should first be tested for proton impact on very heavy target elements. For these elements the inner shell electrons move sufficiently fast for a relativistic description to be mandatory. These relativistic effects are in themselves of some interest, as they can be quite large. After discussion of the formulation of the SCA used throughout this work, a further introduction is given on relativistic effects in Coulomb ionisation. Two papers on electronic relativistic effects in K and L shell ionization follow. The next two papers discuss calculations with an exact Coulomb projectile path. The latter of these also touches upon the inclusion of corrections to the SCA from terms beyond first order perturbation theory. In the last paper of this thesis it is shown how the theoretical apparatus developed for the SCA- calculations can immediately be used also for making calculations of more symmetric systems with the Briggs model. Thus, at least for direct ionization in very slow collisions a unification of the SA and MO approaches has apparently been reached. (JIW)

  14. Time-dependent cylindrical and spherical ion-acoustic solitary structures in relativistic degenerate multi-ion plasmas with positively-charged heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Hossen, M. R.; Nahar, L.; Mamun, A. A. [Jahangirnagar University,Savar, Dhaka (Bangladesh)

    2014-12-15

    The properties of time-dependent cylindrical and spherical, modified ion-acoustic (mIA) solitary structures in relativistic degenerate multi-ion plasmas (containing degenerate electron fluids, inertial positively-, as well as negatively-, charged light ions, and positively-charged static heavy ions) have been investigated theoretically. This investigation is valid for both non-relativistic and ultrarelativistic limits. The well-known reductive perturbation method has been used to derive the Korteweg-de Vries (K-dV) and the mK-dV equations for studying the basic features of solitary waves. The fundamental characteristics of mIA solitary waves are found to be significantly modified by the effects of the degenerate pressures of the electron and the ion fluids, their number densities, and the various charge states of heavy ions. The relevance of our results in astrophysical compact objects like white dwarfs and neutron stars, which are of scientific interest, is briefly discussed.

  15. Procedure for measuring photon and vector meson circular polarization variation with respect to the reaction plane in relativistic heavy-ion collisions

    Science.gov (United States)

    Tang, A. H.; Wang, G.

    2016-08-01

    The electromagnetic (EM) field pattern created by spectators in relativistic heavy-ion collisions plants a seed of positive (negative) magnetic helicity in the hemisphere above (below) the reaction plane. Owing to the chiral anomaly, the magnetic helicity interacts with the fermionic helicity of the collision system and causes photons emitted in upper and lower hemispheres to have different preferences in the circular polarization. Similar helicity separation for massive particles, owing to the global vorticity, is also possible. In this paper, we lay out a procedure to measure the variation of the circular polarization with respect to the reaction plane in relativistic heavy-ion collisions for massless photons, as well as similar polarization patterns for vector mesons decaying into two daughters. We propose to study the yield differentially and compare the yield between upper and lower hemispheres to identify and quantify such effects.

  16. Plastic scintillation detectors for precision time-of-flight measurements of relativistic heavy ions

    CERN Document Server

    Lin, Wen-Jian; Sun, Bao-Hua; He, Liu-Chun; Lin, Wei-Ping; Liu, Chuan-Ye; Tanihata, Isao; Terashima, Satoru; Tian, Yi; Wang, Feng; Wang, Meng; Zhang, Guang-Xin; Zhang, Xue-Heng; Zhu, Li-Hua; Duan, Li-Min; Hu, Rong-Jiang; Liu, Zhong; Lu, Chen-Gui; Ren, Pei-Pei; Sheng, Li-Na; Sun, Zhi-Yu; Wang, Shi-Tao; Wang, Tao-Feng; Xu, Zhi-Guo; Yan, Duo; Yue, Ke; Zheng, Yong

    2016-01-01

    Plastic scintillation detectors for Time-of-Flight (TOF) measurements are almost essential for event-by-event identification of relativistic rare isotopes. In this work, a pair of plastic scintillation detectors of 50 $\\times$ 50 $\\times$ 3$^{t}$ mm$^3$ and 80 $\\times$ 100 $\\times$ 3$^{t}$ mm$^3$ have been set up at the external target facility (ETF), Institute of Modern Physics. Their time, energy and position responses are measured with $^{18}$O primary beam at 400 MeV/nucleon. After the off-line walk-effect and position corrections, the time resolution of the two detectors are determined to be 27 ps ($\\sigma$) and 36 ps ($\\sigma$), respectively. Both detectors have nearly the same energy resolution of 3$\\%$ ($\\sigma$) and position resolution of 2 mm ($\\sigma$). The detectors have been used successfully in nuclear reaction cross section measurements, and will be be employed for upgrading RIBLL2 beam line at IMP as well as for the high energy branch at HIAF.

  17. Streamer chamber and calorimeter measurements in relativistic heavy ion research: Progress in research

    International Nuclear Information System (INIS)

    The first major section of this paper deals with streamer chamber research which is in its final year. The computerized tracking features work well for relatively simple heavy ion events, with multiplicities of 20 and lower, but for future research with very heavy ions and higher bombarding energies the projective geometry is prohibitive. The new area of research using calorimetry takes the opposite approach, in measurements of energy without the need of individual particle resolution. A preliminary experiment was conducted with the E814 collaboration during the spring of 1987 using 10 GeV/nucleon protons and heavy ions on targets of Al, Cu and Pb. The transverse energy distributions are essentially identical for Pb and Cu targets at the high energy end (central collisions), while a significant difference can be seen compared to the Al target. The interpretation is believed to be simply that Cu stops a Si nucleus equally well as a heavier Pb nucleus, i.e., complete stopping of the matter occurs already for the Cu target. A comparison at the .01 barn level for the three targets, compared to a HIJET simulation including the geometry of the calorimeter is given, which clearly demonstrates that finite acceptance is not a complicating factor. The layout of the E814 experiment is shown in the second section of this report. The participant calorimeter will be a 20 ton lead-scintillator sampling device and is in the construction phase at LANL in collaboration with TAMU. A GEANT geometry file output shows the scale of this detector

  18. Density and expansion effects on pion spectra in relativistic heavy-ion collisions

    CERN Document Server

    Ayala, A P; Montaño-Zetina, L M; Ayala, Alejandro; Barreiro, Julio; Montano, Luis M.

    1999-01-01

    We compute the pion inclusive momentum distribution in heavy-ion collisions at AGS energies, assuming thermal equilibrium and accounting for density and expansion effects at the time of decoupling. We compare to data on mid rapidity charged pions produced in central Au + Au collisions and find a very good agreement. The shape of the distribution at low m_t-m is explained in part as an effect arising from the high mean pion density achieved in these reactions. The difference between the positive and negative pion distributions in the same region is attributed in part to the different average yields of each kind of charged pions.

  19. Formation of disoriented chiral condensates in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    Ajit M Srivastava

    2000-07-01

    We present a brief review of the subject of disoriented chiral condensates (DCC). We describe the conventional scenarios for the formation of DCC which have been proposed in the literature. Observable signals, such as fluctuations in neutral to charged pion ratio, are discussed. We then discuss a novel scenario for DCC formation, recently proposed by us, where the entire region of hot partons can get converted into a single large DCC. Our arguments suggest that formation of such large DCC is unlikely in the collision of heavy nuclei, and ultra-high energy hadronic collisions may be better suited for this.

  20. Effect of quark gluon plasma on charm quark produced in relativistic heavy ion collision

    International Nuclear Information System (INIS)

    Charm quarks are produced mainly in the pre-equilibrium stage of heavy ion collision and serve as excellent probes entering the thermalized medium. They come out with altogether different momenta and energies and fragments into D-mesons and decay into non-photonic electrons which are observed experimentally. Here we present the effect of QGP on charm quark production using two different models: first one based on Wang-Huang-Sarcevic model of multiple scattering of partons and the second one is based on Parton Cascade Model with Boltzmann transport equation used for charm quark evolution in QGP

  1. Transport model analysis of particle correlations in relativistic heavy ion collisions at femtometer scales

    OpenAIRE

    Li, Qingfeng; Bleicher, Marcus; Stoecker, Horst

    2006-01-01

    The pion source as seen through HBT correlations at RHIC energies is investigated within the UrQMD approach. We find that the calculated transverse momentum, centrality, and system size dependence of the Pratt-HBT radii $R_L$ and $R_S$ are reasonably well in line with experimental data. The predicted $R_O$ values in central heavy ion collisions are larger as compared to experimental data. The corresponding quantity $\\sqrt{R_O^{2}-R_S^{2}}$ of the pion emission source is somewhat larger than e...

  2. Production study of light fragments emitted at low angle in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    The Diogene plastic wall was built in order to study fragment production in a 0O-6O angular range. After generalities on heavy ion collisions and a description of the Diogene detector, methods used for data analysis allowing identification of charged particles and measurement of their energy and emission angle are presented. From correlation studies between the Diogene events and the plastic wall events, we can have an information on the centrality of collisions. On the other hand, the study of differential cross sections shows two existing sources: one formed by the projectile remnant, at a velocity close to beam velocity and a source of intermediary rapidity formed by the participants. We have shown that even for very central collisions and heavy targets, the target nucleus remains partially transparent. In order to explain projectile fragmentation mechanism, we have used two models: a coalescence model and a thermal model. The first model gives the value of the coalescence radius. It seems that this model does not apply to angles nearing 0O. With the thermal model, we have been able to sort out apparent temperature values which confirm the weak excitation energy of the projectile remnant

  3. New results on Coulomb effects in meson production in relativistic heavy ion collisions

    Directory of Open Access Journals (Sweden)

    Rybicki Andrzej

    2014-01-01

    Full Text Available We propose a new method of investigating the space-time evolution of meson production in heavy ion collisions, by making use of spectator-induced electromagnetic (“Coulomb” effects. The presence of two nuclear remnants (“spectator systems” in the non-central collision generates a strong Coulomb field, which modifies the trajectories of charged final state hadrons. This results in charge-dependent azimuthal anisotropies in final state meson emission. In our approach, this effect can be computed numerically by means of a high-statistics Monte Carlo simulation, using the distance between the meson formation zone and the spectator system as free parameter. Our simulation correctly describes the electromagnetic effect on azimuthal anisotropies observed for π+ and π−mesons in Au+Au collisions at lower RHIC energy, known from data recently reported by the STAR Collaboration. Similarly to our earlier studies of spectator-induced electromagnetic effects, also in the present study we find that these effects offer sensitivity to the position of the meson formation zone with respect to the spectator system. Therefore, we conclude that they can serve as a new tool to investigate the space-time evolution of meson production, and the dynamics of the heavy ion collision.

  4. Antimatter H4Λ hypernucleus production and the H3Λ /3He puzzle in relativistic heavy-ion collisions

    Science.gov (United States)

    Sun, Kai-Jia; Chen, Lie-Wen

    2016-06-01

    We show that the measured yield ratio H3Λ /3He(H¯3¯Λ /¯3He ) in Au +Au collisions at √{sN N}=200 GeV and in Pb +Pb collisions at √{sN N}=2.76 TeV can be understood within a covariant coalescence model if (anti-)Λ particles freeze out earlier than (anti-)nucleons but their relative freeze-out time is closer at √{sN N}=2.76 TeV than at √{sN N}=200 GeV. The earlier (anti-)Λ freeze-out can significantly enhance the yield of (anti)hypernucleus H4Λ (H¯4¯Λ ), leading to that H¯4¯Λ has a comparable abundance with ¯4He and thus provides an easily measured antimatter candidate heavier than ¯4He. The future measurement on H4Λ (H¯4¯Λ ) would be very useful to understand the (anti-)Λ freeze-out dynamics and the production mechanism of (anti)hypernuclei in relativistic heavy-ion collisions.

  5. The Smallest Drops of the Hottest Matter? New Investigations at the Relativistic Heavy Ion Collider (493rd Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Sickles, Anne [BNL Physics Department

    2014-03-19

    Pool sharks at the billiards hall know that sometimes you aim to rocket the cue ball for a head-on collision, and other times, a mere glance will do. Physicists need to know more than a thing or two about collision geometry too, as they sift through data from the billions of ions that smash together at the Relativistic Heavy Ion Collider (RHIC). Determining whether ions crash head-on or just glance is crucial for the physicists analyzing data to study quark-gluon plasma—the ultra-hot, "perfect" liquid of quarks and gluons that existed more than 13 billion years ago, before the first protons and neutrons formed. For these physicists, collision geometry data provides insights about quark-gluon plasma's extremely low viscosity and other unusual properties, which are essential for understanding more about the "strong force" that holds together the nucleus, protons, and neutrons of every atom in the universe. Dr. Sickles explains how physicists use data collected at house-sized detectors like PHENIX and STAR to determine what happens before, during, and after individual particle collisions among billions at RHIC. She also explains how the ability to collide different "species" of nuclei at RHIC—including protons and gold ions today and possibly more with a proposed future electron-ion collider upgrade (eRHIC)—enables physicists to probe deeper into the mysteries of quark-gluon plasma and the strong force.

  6. Probing Transverse Momentum Broadening via Dihadron and Hadron-jet Angular Correlations in Relativistic Heavy-ion Collisions

    CERN Document Server

    Chen, Lin; Wei, Shu-Yi; Xiao, Bo-Wen; Zhang, Han-Zhong

    2016-01-01

    Dijet, dihadron, hadron-jet angular correlations have been reckoned as important probes of the transverse momentum broadening effects in relativistic nuclear collisions. When a pair of high-energy jets created in hard collisions traverse the quark-gluon plasma produced in heavy-ion collisions, they become de-correlated due to the vacuum soft gluon radiation associated with the Sudakov logarithms and the medium-induced transverse momentum broadening. For the first time, we employ the systematical resummation formalism and establish a baseline calculation to describe the dihadron and hadron-jet angular correlation data in $pp$ and peripheral $AA$ collisions where the medium effect is negligible. We demonstrate that the medium effects, especially the so-called jet quenching parameter $\\hat q$, can be extracted from the angular de-correlations observed in $AA$ collisions. A global $\\chi^2$ analysis of dihadron and hadron-jet angular correlation data renders the best fit $\\langle \\hat q L\\rangle_{\\textrm{tot}} \\si...

  7. Study of the correlation of charge separation of the chiral magnetic effect in Relativistic Heavy-ion Collisions

    CERN Document Server

    Feng, Sheng-Qin; Sun, Fei; Zhong, Yang; Yin, Zhong-Bao

    2016-01-01

    It was pointed out that the Chiral Magnetic Effect is a process of charge separation with respect to the reaction plane. There is one kind of phenomenon of gauge field configurations with nonzero topological charge, which can be a sphaleron in the QCD vacuum. At high temperatures, one expects that the sphaleron process is a dominant process. One finds that left-handed quarks will become right-handed quarks, and right-handed quarks will remain right-handed in a region with negative topological charge. The strong magnetic field produced in relativistic heavy-ion collisions interacts with the magnetic moment of the quarks and locates the spins of quarks with positive (negative) electric charge to be parallel (anti-parallel) to the field direction. The Chiral Separation Effect is a similar effect in which the occurrence of a vector charge, e.g. electric charge, causes a separation of chiralities. We calculate the chiral separation effects during RHIC and LHC energy regions by studying the detailed chiral charge s...

  8. Cross section for production of low-energy electron-positron pairs by relativistic heavy ions

    Science.gov (United States)

    Eby, P. B.

    1991-01-01

    Starting with the lowest-order unscreened QED matrix element for electron-positron pair production by heavy charged particles, the paper calculates the cross section for this process differential in all independent variables and valid for all pair energies small compared to the incident particle energy. Integration over the possible emission angles of one of the pair members gives an expression that is valid for low-energy pairs that can be compared with previous work based on the Weizsaecker-Williams method. Integration over the possible angles of the other pair member then yields an expression identical to one derived by Racah. The high energy-transfer limit of the expression for the cross section integrated over electron and positron angles is found to be identical to that of Kelner in the unscreened case.

  9. A Tale of Tails: Photon Rates and Flow in Ultra-Relativistic Heavy Ion Collisions

    CERN Document Server

    McLerran, Larry

    2015-01-01

    We consider the possibility that quark and gluon distributions in the medium created in high energy heavy ion collisions may be modified by a power law tail at energies much higher than the temperature. We parametrize such a tail by Tsallis distributions with an exponent motivated by phenomenology. These distributions are characterized by an effective temperature scale that we assume to evolve in time like the temperature for thermal distributions. We find that including such a tail increases the rates for photon production and significantly delays the emission times for photons of a fixed energy. We argue that these effects are sufficiently large that they should be able to account for photon yields and flow patterns seen in LHC and RHIC experiments.

  10. Interactions of $B_{c}$ Meson in Relativistic Heavy-Ion Collisions

    CERN Document Server

    Irfan, Shaheen; Masud, Bilal

    2015-01-01

    We calculate the absorbtion cross-sections of $B_{c}$ mesons by $\\pi$ and $\\rho$ mesons including anomalous processes using an effective hadronic Lagrangian. The enhancement of Bc production is expected due to QGP formation in heavy-ion experiments. However it is also expected that the production rate of Bc meson can be affected due to the interaction with comovers. These processes are relevant for experiments at RHIC. Thermal average cross-sections of $B_{c}$ are evaluated with form factor when a cut off parameter in it is 1 and 2 GeV. Using these thermal average cross-sections in the kinetic equation we investigate the time evolution of $B_{c}$ mesons due to dissociation in the hadronic matter formed at RHIC.

  11. FPC conditioning cart at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W.; Ben-Zvi, I.; Altinbas, F.Z.; Belomestnykh, S.; Burrill, A.; Cole, M.; Deonarine, J.; Jamilkowski, J.; Kayran, D.; Laloudakis, N.; Masi Jr, L.; McIntyre, G.; Pate, D.; Philips, D.; Seda, T.; Steszyn, A.; Tallerico, T.; Todd, R.; Weiss, D.; White, G.; Zaltsman, A.

    2011-03-28

    The 703 MHz superconducting gun for the BNL Energy Recovery Linac (ERL) prototype has two fundamental power couplers (FPCs), and each of them will deliver up to 500 kW of CW RF power. In order to prepare the couplers for high power RF service and process multipacting, the FPCs should be conditioned prior to installation into the gun cryomodule. A conditioning cart based test stand, which includes a vacuum pumping system, controllable bake-out system, diagnostics, interlocks and data log system has been designed, constructed and commissioned by collaboration of BNL and AES. This paper presents FPC conditioning cart systems and the conditioning process.

  12. K{alpha}{sub 1} radiation from heavy, helium-like ions produced in relativistic collisions

    Energy Technology Data Exchange (ETDEWEB)

    Surzhykov, A.; Jentschura, U.D. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Stoehlker, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Fritzsche, S. [Kassel Univ. (Germany). Inst. fuer Physik

    2006-11-15

    Bound-state transitions in few-electron, heavy ions following radiative electron capture are studied within the framework of the density matrix theory and the multiconfiguration Dirac-Fock approach. Special attention is paid to the K{alpha}{sub 1}(1s{sub 1/2}2p{sub 3/2}{sup 1,3}P{sub J=1,2}{yields}1s{sub 1/2}{sup 2} {sup 1}S{sub J=0}) radiative decay of helium-like uranium U{sup 90+} projectiles. This decay has recently been observed at the GSI facility in Darmstadt, giving rise to a surprisingly isotropic angular distribution, which is inconsistent with previous experiments and calculations based on a 'one-particle' model. We show that the unexpected isotropy essentially results from the mutual cancellation of the angular distributions of the {sup 1}P{sub 1}{yields}{sup 1}S{sub 0} electric dipole and {sup 3}P{sub 2}{yields}{sup 1}S{sub 0} magnetic quadrupole transitions, both of which contribute to the K{alpha}{sub 1} radiation. Detailed computations on the anisotropy of the K{alpha}{sub 1} radiation have been carried out for a wide range of projectile energies and are compared to available experimental data. (orig.)

  13. Lambda-Lambda interaction from two-particle intensity correlation in relativistic heavy-ion collisions

    CERN Document Server

    Ohnishi, Akira; Furumoto, Takenori

    2015-01-01

    We investigate $\\Lambda\\Lambda$ interaction dependence of the $\\Lambda\\Lambda$ intensity correlation in high-energy heavy-ion collisions. By analyzing the correlation data recently obtained by the STAR collaboration based on theoretically proposed $\\Lambda\\Lambda$ interactions, we give a constraint on the $\\Lambda\\Lambda$ scattering length, $-1.25~\\text{fm} < a_0 < 0$, suggesting that $\\Lambda\\Lambda$ interaction is weakly attractive and there is no loosely bound state. In addition to the fermionic quantum statistics and the $\\Lambda\\Lambda$ interaction, effects of collective flow, feed-down from $\\Sigma^0$, and the residual source are also found to be important to understand the data. We demonstrate that the correlation data favor negative $\\Lambda\\Lambda$ scattering length with the pair purity parameter $\\lambda=(0.67)^2$ evaluated by using experimental data on the $\\Sigma^0/\\Lambda$ ratio, while the positive scattering length could be favored when we regard $\\lambda$ as a free fitting parameter.

  14. Applications of many-body physics to relativistic heavy ion collisions

    Science.gov (United States)

    Fillion-Gourdeau, Francois

    In this dissertation, many-body physics techniques are used to study and improve ideas related to the description of heavy ion collisions at very high energy. The first part of the thesis concerns the production of tensor mesons in proton-proton (pp) collisions. An effective theory where the f2 meson couples to the energy-momentum tensor is proposed and a comparison of the inclusive cross-section computed in the collinear factorization, the k⊥-factorization and the color glass condensate is performed. A study of the phenomenology in pp collisions then shows a strong dependence on the parametrization of the unintegrated distribution function. The conclusion is that f2 meson production can be utilized to improve the understanding of the proton wave-function. In the second part, a similar investigation is performed by analysing the production cross-section of the eta' meson in pp and proton-nucleus (pA) collisions. The nucleus and proton are described by the CGC and the k⊥ -factorization respectively. A new technique for the computation of Wilson lines---color charge densities correlators in the McLerran-Venugopalan model is developped. The phenomenology shows that the cross-section in pA collisions is very sensitive to the value of the saturation scale, a crucial ingredient of the CGC picture. In the third part of the thesis, the collision term of the Boltzmann equation is derived from first principles at all orders and for any number of participating particles, starting from the full out-of-equilibrium quantum field theory and using the multiple scattering expansion. Finally, the emission of photons from a non-abelian strong classical field is investigated. A formalism based on Schwinger-Keldysh propagators relating the production rate of photons to the retarded solution of the Dirac equation in a background field is presented.

  15. Relativistic Noise

    OpenAIRE

    Kapusta, Joseph; Mueller, Berndt; Stephanov, Misha

    2012-01-01

    The relativistic theory of hydrodynamic fluctuations, or noise, is derived and applied to high energy heavy ion collisions. These fluctuations are inherent in any space-time varying system and are in addition to initial state fluctuations. We illustrate the effects with the boost-invariant Bjorken solution to the hydrodynamic equations. Long range correlations in rapidity are induced by propagation of sound modes. The magnitude of these correlations are directly proportional to the viscositie...

  16. Rapidity-dependent spectra from a single-freeze-out model of relativistic heavy-ion collisions

    Science.gov (United States)

    Biedroń, Bartłomiej; Broniowski, Wojciech

    2007-05-01

    An extension of the single-freeze-out model with thermal and geometric parameters dependent on the spatial rapidity, α∥, is used to describe the rapidity and transverse-momentum spectra of pions, kaons, protons, and antiprotons measured at the Relativistic Heavy Ion Collider at sNN=200GeV by the BRAHMS Collaboration. THERMINATOR is used to perform the necessary simulation, which includes all resonance decays. The result of the fit to the rapidity spectra in the range of the BRAHMS data is the expected growth of the baryon and strange chemical potentials with the magnitude of α∥, whereas the freeze-out temperature is kept fixed. The value of the baryon chemical potential at α∥~3, which is the relevant region for particles detected at the BRAHMS forward rapidity y~3, is about 200GeV, i.e., lies in the range of the values obtained for the highest SPS energy. The chosen geometry of the fireball has a decreasing transverse size as the magnitude of α∥ is increased, which also corresponds to decreasing transverse flow. This feature is verified by reproducing the transverse momentum spectra of pions and kaons at various rapidities. The strange chemical potential obtained from the fit to the K+/K- ratio is such that the local strangeness density in the fireball is compatible with zero. The resulting rapidity spectra of net protons are described qualitatively in the model. As a result of the study, the knowledge of the “topography” of the fireball is achieved, making other calculations possible. As an example, we give predictions for the rapidity spectra of hyperons.

  17. PHENIX Conceptual Design Report. An experiment to be performed at the Brookhaven National Laboratory Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Nagamiya, Shoji; Aronson, Samuel H.; Young, Glenn R.; Paffrath, Leo

    1993-01-29

    The PHENIX Conceptual Design Report (CDR) describes the detector design of the PHENIX experiment for Day-1 operation at the Relativistic Heavy Ion Collider (RHIC). The CDR presents the physics capabilities, technical details, cost estimate, construction schedule, funding profile, management structure, and possible upgrade paths of the PHENIX experiment. The primary goals of the PHENIX experiment are to detect the quark-gluon plasma (QGP) and to measure its properties. Many of the potential signatures for the QGP are measured as a function of a well-defined common variable to see if any or all of these signatures show a simultaneous anomaly due to the formation of the QGP. In addition, basic quantum chromodynamics phenomena, collision dynamics, and thermodynamic features of the initial states of the collision are studied. To achieve these goals, the PHENIX experiment measures lepton pairs (dielectrons and dimuons) to study various properties of vector mesons, such as the mass, the width, and the degree of yield suppression due to the formation of the QGP. The effect of thermal radiation on the continuum is studied in different regions of rapidity and mass. The e{mu} coincidence is measured to study charm production, and aids in understanding the shape of the continuum dilepton spectrum. Photons are measured to study direct emission of single photons and to study {pi}{sup 0} and {eta} production. Charged hadrons are identified to study the spectrum shape, production of antinuclei, the {phi} meson (via K{sup +}K{sup {minus}} decay), jets, and two-boson correlations. The measurements are made down to small cross sections to allow the study of high p{sub T} spectra, and J/{psi} and {Upsilon} production. The PHENIX collaboration consists of over 300 scientists, engineers, and graduate students from 43 institutions in 10 countries. This large international collaboration is supported by US resources and significant foreign resources.

  18. Highlights from BNL-RHIC

    CERN Document Server

    Tannenbaum, M J

    2012-01-01

    Recent highlights from Brookhaven National Laboratory and the Relativistic Heavy Ion Collider (RHIC) are reviewed and discussed. Topics include: Discovery of the strongly interacting Quark Gluon Plasma (sQGP) in 2005; RHIC machine operation in 2011 as well as latest achievements from the superconducting Magnet Division and the National Synchrotron Light Source II project. Highlights from QGP physics at RHIC include: comparison of new measurements of charged multiplicity in A+A collisions by ALICE at the LHC to previous RHIC measurements; Observation of the anti-alpha particle by the STAR experiment; Collective Flow, including the Triangular Flow discovery and the latest results on v3; the RHIC beam energy scan in search of the QCD critical point. The pioneering use at RHIC of hard-scattering as a probe of the sQGP will also be reviewed and the latest results presented including: jet-quenching via suppression of high pT particles and two particle correlations; new results on fragmentation functions using gamma...

  19. Proceedings of RIKEN BNL Research Center Workshop: Understanding QGP through Spectral Functions and Euclidean Correlators (Volume 89)

    Energy Technology Data Exchange (ETDEWEB)

    Mocsy,A.; Petreczky, P.

    2008-06-27

    In the past two decades, one of the most important goals of the nuclear physics community has been the production and characterization of the new state of matter--Quark-Gluon Plasma (QGP). Understanding how properties of hadrons change in medium, particularly, the bound state of a very heavy quark and its antiquark, known as quarkonium, as well as determining the transport coefficients is crucial for identifying the properties of QGP and for the understanding of the experimental data from RHIC. On April 23rd, more than sixty physicists from twenty-seven institutions gathered for this three-day topical workshop held at BNL to discuss how to understand the properties of the new state of matter obtained in ultra-relativistic heavy ion collisions (particularly at RHIC-BNL) through spectral functions. In-medium properties of the different particle species and the transport properties of the medium are encoded in spectral functions. The former could yield important signatures of deconfinement and chiral symmetry restoration at high temperatures and densities, while the later are crucial for the understanding of the dynamics of ultra-relativistic heavy ion collisions. Participants at the workshop are experts in various areas of spectral function studies. The workshop encouraged direct exchange of scientific information among experts, as well as between the younger and the more established scientists. The workshops success is evident from the coherent picture that developed of the current understanding of transport properties and in-medium particle properties, illustrated in the current proceedings. The following pages show calculations of meson spectral functions in lattice QCD, as well as implications of these for quarkonia melting/survival in the quark gluon plasma; Lattice calculations of the transport coefficients (shear and bulk viscosities, electric conductivity); Calculation of spectral functions and transport coefficients in field theories using weak coupling

  20. Indirect relativistic bridge and substituent effects from the 'heavy' environment on the one-bond and two-bond (13)C-(1)H spin-spin coupling constants.

    Science.gov (United States)

    Rusakova, Irina L; Rusakov, Yury Yu; Krivdin, Leonid B

    2016-01-01

    Indirect relativistic bridge effect (IRBE) and indirect relativistic substituent effect (IRSE) induced by the 'heavy' environment of the IV-th, V-th and VI-th main group elements on the one-bond and geminal (13)C-(1)H spin-spin coupling constants are observed, and spin-orbit parts of these two effects were interpreted in terms of the third-order Rayleigh-Schrödinger perturbation theory. Both effects, IRBE and IRSE, rapidly increase with the total atomic charge of the substituents at the coupled carbon. The accumulation of IRSE for geminal coupling constants is not linear with respect to the number of substituents in contrast to the one-bond couplings where IRSE is an essentially additive quantity. PMID:26352434

  1. The different energy loss mechanisms of inclusive and b-tagged reconstructed jets within ultra-relativistic heavy-ion collisions

    CERN Document Server

    Senzel, Florian; Xu, Zhe; Greiner, Carsten

    2016-01-01

    The phenomenon of jet quenching provides essential information about the properties of hot and dense matter created in ultra-relativistic heavy-ion collisions. Recent results from experiments at the Large Hadron Collider (LHC) show evidence for an unexpectedly similar suppression of both light and heavy flavor jets. Furthermore, the role of radiative energy loss of heavy quarks is still under active discussion within the theoretical community. By employing the parton cascade BAMPS (Boltzmann Approach to Multi-Parton Scatterings), which numerically solves the 3+1D Boltzmann equation both for light and heavy flavor partons, we calculate the nuclear modification factor of inclusive and b-tagged reconstructed jets in 0-10% central $\\sqrt{s}$ = 2.76 ATeV Pb+Pb collisions. Based on perturbative QCD cross sections we find a rather similar suppression of light and heavy flavor jets. To further investigate light and heavy flavor energy loss we predict a different $R$ dependence of the suppression of inclusive and b-ta...

  2. The Alice experiment for the study of ultra relativistic heavy ion collisions; Experience ALICE pour l'etude des collisions d'ions lourds ultra-relativistes au CERN-LHC

    Energy Technology Data Exchange (ETDEWEB)

    Forestier, B

    2003-12-01

    Alice is the detector dedicated to the study of heavy ions at the LHC (large hadron collider). It will allow scientists to investigate all the signatures of quark-gluon plasma (QGP). The spectrometer of the dimuon arm of Alice has been designed to study the production of high mass resonances through their dimuon decay. The first chapter is dedicated to some aspects of the physics of ultra-relativistic heavy ion: confinement and de-confinement of quarks, the absence of heavy resonances as a signature for the presence of QGP. The second chapter presents Alice and its ancillary detectors. The third chapter deals with the trigger system of the dimuon spectrometer, a detailed algorithm of this system is given. A method for the optimization of the trigger response is presented in the fourth chapter. The fifth chapter describes the testing of a prototype of the trigger system, this testing with muons has shown that the efficiency of the track reconstruction of the trigger system and the efficiency of the resistive plate chamber reach 98%.In the sixth chapter the author comments the simulations of the production of heavy resonances from Pb-Pb collisions as a function of centrality. (A.C.)

  3. B-meson decay constants from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

    CERN Document Server

    Christ, Norman H; Izubuchi, Taku; Kawanai, Taichi; Lehner, Christoph; Soni, Amarjit; Van de Water, Ruth S; Witzel, Oliver

    2014-01-01

    We calculate the B-meson decay constants f_B, f_Bs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b-quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of a ~ 0.11, 0.086 fm with unitary pion masses as light as M_pi ~ 290 MeV; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the b-quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the lattice heavy-light axial-vector current using a mostly nonperturbative method in which we compute the bulk of the matching factor nonperturbatively, with a small correction, that is close to unity, in lattice perturbation theory. We also impr...

  4. SCIENTIFIC PRESENTATION. 7TH MEETING OF THE MANAGEMENT STEERING COMMITTEE OF THE RIKEN BNL COLLABORATION.

    Energy Technology Data Exchange (ETDEWEB)

    LEE,T.D.

    2001-02-13

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkysho,'' (RIKEN) The Institute of Physical and Chemical Research, of Japan. The Center is dedicated to the study of strong 'interactions, including hard QCD/spin physics, lattice QCD and RHIC (Relativistic Heavy Ion Collider) physics through nurturing of a new generation of young physicists. The Director of RBRC is Professor T. D. Lee. The first years were dedicated to the establishment of a theory group. This has essentially been completed consisting of Fellows, Postdocs, and RHIC Physics/University Fellows, with an active group of consultants. The center also organizes an extensive series of workshops on specific topics in strong interactions with an accompanying series of published proceedings. In addition, a 0.6 teraflop parallel processor computer has been constructed and operational since August 1998. It was awarded the Supercomputer 1998 Gordon Bell Prize for price performance. An active experimental group centered around the spin physics program at RHIC has subsequently also been established at RBRC. It presently consists of five Fellows, one Postdoc and several scientific collaborators with more appointments being expected in the near future. Members and participants of RBRC on occasion will develop articles such as this one, in the nature of a status report or a general review.

  5. SCIENTIFIC PRESENTATION. 7TH MEETING OF THE MANAGEMENT STEERING COMMITTEE OF THE RIKEN BNL COLLABORATION.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.D.

    2001-02-13

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory. It is funded by the ''Rikagaku Kenkysho,'' (RIKEN) The Institute of Physical and Chemical Research, of Japan. The Center is dedicated to the study of strong interactions, including hard QCD/spin physics, lattice QCD and RHIC (Relativistic Heavy Ion Collider) physics through nurturing of a new generation of young physicists. The Director of RBRC is Professor T. D. Lee. The first years were dedicated to the establishment of a theory group. This has essentially been completed consisting of Fellows, Postdocs, and RHIC Physics/University Fellows, with an active group of consultants. The center also organizes an extensive series of workshops on specific topics in strong interactions with an accompanying series of published proceedings. In addition, a 0.6 teraflop parallel processor computer has been constructed and operational since August 1998. It was awarded the Supercomputer 1998 Gordon Bell Prize for price performance. An active experimental group centered around the spin physics program at RHIC has subsequently also been established at RBRC. It presently consists of five Fellows, one Postdoc and several scientific collaborators with more appointments being expected in the near future. Members and participants of RBRC on occasion will develop articles such as this one, in the nature of a status report or a general review.

  6. Relativistic diffusion.

    Science.gov (United States)

    Haba, Z

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  7. Single electrons from heavy-flavor decays in collisions at.

    Science.gov (United States)

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Devismes, A; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; Hayashi, N; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; 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; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, 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; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; van Hecke, H W; Velkovska, J; Velkovsky, M; Veszprémi, V; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zhou, S J; Zolin, L

    2006-01-27

    The invariant differential cross section for inclusive electron production in p+p collisions at [FORMULA: SEE TEXT] has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.4heavy flavor, i.e., charm quarks or, at high , bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy-flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined to be [FORMULA: SEE TEXT]. PMID:16486684

  8. Relativistic heavy ions physics

    International Nuclear Information System (INIS)

    Central nuclear collisions at energies far above 1 GeV/nucleon may provide for conditions, where the transition from highly excited hadronic matter into quark matter or quark-gluon plasma can be probed. We review current ideas about the nature of, and signals for, this transition, and we discuss the (hadronic) string model approach to the nuclear collisions dynamics. At even higher energies in the TeV/nucleon range peripheral nuclear collisions may become a laboratory for electroweak physics at the unification scale allowing, e.g., for Higgs boson production. 42 refs., 29 figs.,

  9. Relativistic heavy cosmic rays

    Science.gov (United States)

    Mewaldt, R. A.; Fernandez, J. I.; Israel, M. H.; Klarmann, J.; Binns, W. R.

    1972-01-01

    During three balloon flights of a 1 sq m sr ionization chamber/Cerenkov counter detector system, measurements were made of the atmospheric attenuation, flux, and charge composition of cosmic ray nuclei with 16 is less than or = Z is less than or = 30 and rigidity greater than 4.5 GV. The attenuation mean free path in air of VH (20 less than or = Z less than or = 30) nuclei is found to be 19.7 + or - 1.6 g/sq cm, a value somewhat greater than the best previous measurement. The attenuation mean free path of iron is found to be 15.6 + or - 2.2 g/sq cm, consistent with predictions of geometric cross-section formulae. An absolute flux of VH nuclei 10 to 20% higher than earlier experiments at similar geomagnetic cutoff and level of solar activity was measured. The relative abundances of even-charged nuclei are found to be in good agreement with results of other recent high resolution counter experiments. The observed cosmic ray chemical composition implies relative abundances at the cosmic ray source of Ca/Fe = 0.12 + or - 0.04 and S/Fe = 0.14 + or - 0.05.

  10. Non-relativistic leptogenesis

    International Nuclear Information System (INIS)

    In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe. We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections. We determine the leading order coefficients in these equations, and the first relativistic corrections. The non-relativistic approximation works remarkably well. It appears to be consistent with results obtained using a Boltzmann equation taking into account the momentum distribution of the heavy neutrinos, while being much simpler. We also compute radiative corrections to some of the coefficients in the rate equations. Their effect is of order 1% in the regime favored by neutrino oscillation data. We obtain the correct leading order lepton number washout rate in this regime, which leads to large ( ∼ 20%) effects compared to previous computations

  11. Non-relativistic leptogenesis

    CERN Document Server

    Bodeker, Dietrich

    2014-01-01

    In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe. We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections. We determine the leading order coefficients in these equations, and the first relativistic corrections. The non-relativistic approximation works remarkably well. It appears to be consistent with results obtained using a Boltzmann equation taking into account the momentum distribution of the heavy neutrinos, while being much simpler. We also compute radiative corrections to some of the coefficients in the rate equations. Their effect is of order 1% in the regime favored by neutrino oscillation data. We obtain the correct leading order lepton number washout rate in this regime, which leads to large (~ 20%) effects compared to previous computations.

  12. Non-relativistic leptogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Bödeker, Dietrich; Wörmann, Mirco, E-mail: bodeker@physik.uni-bielefeld.de, E-mail: mwoermann@physik.uni-bielefeld.de [Fakultät für Physik, Universität Bielefeld, Bielefeld, D-33615 (Germany)

    2014-02-01

    In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe. We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections. We determine the leading order coefficients in these equations, and the first relativistic corrections. The non-relativistic approximation works remarkably well. It appears to be consistent with results obtained using a Boltzmann equation taking into account the momentum distribution of the heavy neutrinos, while being much simpler. We also compute radiative corrections to some of the coefficients in the rate equations. Their effect is of order 1% in the regime favored by neutrino oscillation data. We obtain the correct leading order lepton number washout rate in this regime, which leads to large ( ∼ 20%) effects compared to previous computations.

  13. Two models with rescattering for high energy heavy ion collisions

    Science.gov (United States)

    Bøggild, H.; Hansen, Ole; Humanic, T. J.

    2006-12-01

    The effects of hadronic rescattering in high energy relativistic Au+Au collisions are studied using two very different models to describe the early stages of the collision. One model is based on a hadronic thermal picture and the other on a superposition of parton-parton collisions. Operationally, the output hadrons from each of these models are used as input to a hadronic rescattering calculation. The results of the rescattering calculations from each model are then compared with rapidity and transverse momentum distributions from the BNL Relativistic Heavy Ion Collider BRAHMS experiment. In spite of the different points of view of the two models of the initial stage, after rescattering, the observed differences between the models are mostly “washed out” and both models give observables that agree roughly with each other and with experimental data.

  14. Nonextensive statistical effects in the quark-gluon plasma formation at relativistic heavy-ion collisions energies

    Science.gov (United States)

    Gervino, Gianpiero; Lavagno, Andrea; Pigato, Daniele

    2012-06-01

    We investigate the relativistic equation of state of hadronic matter and quark-gluon plasma at finite temperature and baryon density in the framework of the non-extensive statistical mechanics, characterized by power-law quantum distributions. We impose the Gibbs conditions on the global conservation of baryon number, electric charge and strangeness number. For the hadronic phase, we study an extended relativistic mean-field theoretical model with the inclusion of strange particles (hyperons and mesons). For the quark sector, we employ an extended MIT-Bag model. In this context we focus on the relevance of non-extensive effects in the presence of strange matter.

  15. Energy flow and stopping in relativistic heavy-ion collisions at Elab/A=14.6 GeV

    International Nuclear Information System (INIS)

    Collisions of 28Si+Al, Cu, Pb at Elab/A=14.6 GeV were studied in a calorimetry-based experiment at the BNL Alternating Gradient Synchrotron. Transverse-energy production was measured for pseudorapidities -0.5<η<0.8. Correlations with the spectra and multiplicity of neutrons and protons emitted into a forward 0.8 degree cone demonstrate quantitatively the large amount of nuclear stopping observed in these reactions. Calculations in hadronic-fireball or nucleon-nucleon based models underpredict the measured transverse-energy production for Si+Pb and indicate the need to include rescattering of secondaries and /or contributions from target fragmentation

  16. BNL Activities in Advanced Neutron Source Development: Past and Present

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, J.B.; Ludewig, H.; Montanez, P.; Todosow, M.; Smith, G.C.; Larese, J.Z.

    1998-06-14

    Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In this report we discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

  17. BNL ACTIVITIES IN ADVANCED NEUTRON SOURCE DEVELOPMENT: PAST AND PRESENT

    Energy Technology Data Exchange (ETDEWEB)

    HASTINGS,J.B.; LUDEWIG,H.; MONTANEZ,P.; TODOSOW,M.; SMITH,G.C.; LARESE,J.Z.

    1998-06-14

    Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In the sections below the authors discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

  18. B-meson decay constants from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Norman H. [Columbia Univ., New York, NY (United States); Flynn, Jonathan M. [Univ. of Southampton, Southampton (United Kingdom); Izubuchi, Taku [Brookhaven National Lab. (BNL), Upton, NY (United States); Kawanai, Taichi [RIKEN, Wako (Japan); Brookhaven National Lab. (BNL), Upton, NY (United States); Lehner, Christoph [Brookhaven National Lab. (BNL), Upton, NY (United States); Soni, Amarjit [Brookhaven National Lab. (BNL), Upton, NY (United States); Van de Water, Ruth S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Witzel, Oliver [Boston Univ., Boston, MA (United States)

    2015-03-10

    We calculate the B-meson decay constants fB, fBs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b-quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of a ≈ 0.11, 0.086 fm with unitary pion masses as light as Mπ ≈ 290 MeV; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the b-quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the lattice heavy-light axial-vector current using a mostly nonperturbative method in which we compute the bulk of the matching factor nonperturbatively, with a small correction, that is close to unity, in lattice perturbation theory. We also improve the lattice heavy-light current through O(αsa). We extrapolate our results to the physical light-quark masses and continuum using SU(2) heavy-meson chiral perturbation theory, and provide a complete systematic error budget. We obtain fB0 = 196.2(15.7) MeV, fB+ = 195.4(15.8) MeV, fBs = 235.4(12.2) MeV, fBs/fB0 = 1.193(59), and fBs/fB+ = 1.220(82), where the errors are statistical and total systematic added in quadrature. In addition, these results are in good agreement with other published results and provide an important independent cross check of other three-flavor determinations of B-meson decay constants using staggered light quarks.

  19. Isoscalar giant monopole resonance for drip-line and super heavy nuclei in the framework of a relativistic mean field formalism with scaling calculation

    CERN Document Server

    Biswal, S K

    2014-01-01

    We study the isoscalar giant monopole resonance for drip-lines and super heavy nuclei in the frame work of a relativistic mean field theory with scaling approach. The well known extended Thomas-Fermi approximation in the non-linear $\\sigma$-$\\omega$ model is used to estimate the giant monopole excitation energy for some selected light spherical nuclei starting from the region of proton to neutron drip-lines. The application is extended to super heavy region for Z=114 and 120, which are predicted by several models as the next proton magic number beyond Z=82. We compared the excitation energy obtained by four successful force parameters NL1, NL3, NL3$^*$ and FSUGold. The monopole energy decreases toward the proton and neutron drip-lines in an isotopic chain for lighter mass nuclei contrary to a monotonous decrease for super heavy isotopes. The maximum and minimum monopole excitation energies are obtained for nuclei with minimum and maximum isospin, respectively in an isotopic chain.

  20. Centrality dependence of identified particles in relativistic heavy ion collisions at sqrt(s)= 7.7-62.4 GeV

    CERN Document Server

    Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Bai, X; Bairathi, V; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandenburg, D; Brandin, A V; Bunzarov, I; Butterworth, J; Caines, H; Calder{ó}n~de~la~Barca~S{á}nchez, 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; Chisman, O; 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, A; Gupta, S; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; 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; 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; Kollegger, T; Kosarzewski, L K; 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, X; Li, W; Li, C; Li, Z M; Li, Y; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, R; Ma, L; Ma, Y G; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; 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; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D; 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, R; Raniwala, S; 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; 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; Singha, S; Skoby, M J; Smirnov, N; Smirnov, D; 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, X; Sun, Z; Sun, X M; Sun, Y; Surrow, B; Svirida, N; Szelezniak, M A; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A; Thaeder, 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; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, F; Wang, J S; Wang, Y; Wang, G; Wang, H; Webb, J C; Webb, G; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu,; Wu, Y F; Xiao, Z G; Xie, W; Xin, K; Xu, N; Xu, Q H; Xu, Z; Xu, Y F; Xu, H; Yang, C; Yang, Y; 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, Z; Zhang, S; Zhang, J; Zhang, Y; Zhang, J B; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2016-01-01

    Elliptic flow (v_{2}) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at sqrt{s_{NN}}= 7.7-62.4 GeV are presented for three centrality classes. The centrality dependence and the data at sqrt{s_{NN}}= 14.5 GeV are new. Except at the lowest beam energies we observe a similar relative v_{2} baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v_{2} for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with AMPT calculations and fit with a Blast Wave model.

  1. Applying Bayesian parameter estimation to relativistic heavy-ion collisions: simultaneous characterization of the initial state and quark-gluon plasma medium

    CERN Document Server

    Bernhard, Jonah E; Bass, Steffen A; Liu, Jia; Heinz, Ulrich

    2016-01-01

    We quantitatively estimate properties of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions utilizing Bayesian statistics and a multi-parameter model-to-data comparison. The study is performed using a recently developed parametric initial condition model, TRENTO, which interpolates among a general class of particle production schemes, and a modern hybrid model which couples viscous hydrodynamics to a hadronic cascade. We calibrate the model to multiplicity, transverse momentum, and flow data and report constraints on the parametrized initial conditions and the temperature-dependent transport coefficients of the quark-gluon plasma. We show that initial entropy deposition is consistent with a saturation-based picture, extract a relation between the minimum value and slope of the temperature-dependent specific shear viscosity, and find a clear signal for a nonzero bulk viscosity.

  2. The Lund–York–Cologne Calorimeter (LYCCA): Concept, design and prototype developments for a FAIR-NUSTAR detector system to discriminate relativistic heavy-ion reaction products

    International Nuclear Information System (INIS)

    The concept, design and prototype developments for the Lund–York–Cologne CAlorimeter (LYCCA) is presented. LYCCA is a modular device for the NUclear STructure, Astrophysics and Reactions (NUSTAR) science pillar of the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. LYCCA is designed to discriminate heavy ions produced in nuclear reactions induced by relativistic radioactive ion beams. Measurements of energy loss, total energy, and time-of-flight allow the derivation of proton number, Z, and mass number, A, of the reaction products. LYCCA-inherent tracking of the flight paths of the reaction products enables coincident HIgh-resolution in-beam γ-ray SPECtroscopy (HISPEC) of atomic nuclei far from the line of β-stability

  3. Measurement of the ratio of the sixth order to the second order cumulant of net-proton multiplicity distributions in relativistic heavy-ion collisions

    CERN Document Server

    Chen, Lizhu; Cui, Fenping; Wu, Yuanfang

    2016-01-01

    We investigate the measurement of the sixth order cumulant and its ratio to the second order cumulant ($C_6/C_2$) in relativistic heavy-ion collisions. The influence of statistics and different methods of centrality bin width correction on $C_6/C_2$ of net-proton multiplicity distributions is demonstrated. There is no satisfactory method to extract $C_6/C_2$ with the current statistics recorded at lower energies by STAR at RHIC. With statistics comparable to the expected statistics at the planned future RHIC Beam Energy Scan II (BES II), no energy dependence of $C_6/C_2$ is observed in central collisions using the UrQMD model. We find if the transition signal is as strong as predicted by the PQM model, then it is hopefully observed at the upcoming RHIC BES II.

  4. New peculiarities in angular distribution of Cherenkov radiation from relativistic heavy ions caused by their stopping in radiator: numerical and theoretical research

    Science.gov (United States)

    Fiks, E. I.; Bogdanov, O. V.; Pivovarov, Yu L.

    2012-05-01

    A new method and theoretical base for calculation of the Cherenkov Radiation (ChR) angular distribution from relativistic heavy ions (RHI) taking into account stopping in radiator is suggested. Our method is based on the thin radiator approximation and the Bethe-Bloch formula for ionization energy loss (stopping) and provides fast calculations without using any special software. The simple formula for estimation of the ChR angular distribution width in vicinity of the Cherenkov angle taking into account RHI stopping in radiator is obtained. New peculiarities of ChR - dependence on the RHI charge and mass (isotopic effect), emission wavelength (index of refraction) and radiator length - are studied. These new features of ChR from RHI allow for their possible applications to simultaneously reconstruction of both velocity and charge of RHI penetrating through radiator and even to measure the masses of isotopes or radiator stopping power.

  5. Exact Relativistic `Antigravity' Propulsion

    Science.gov (United States)

    Felber, Franklin S.

    2006-01-01

    The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.

  6. Exact Relativistic 'Antigravity' Propulsion

    CERN Document Server

    Felber, F S

    2006-01-01

    The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3^-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.

  7. Proceedings of RIKEN BNL Research Center Workshop: The Approach to Equilibrium in Strongly Interacting Matter. Volume 118

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Venugopalan, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berges, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaizot, J. -P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gelis, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-04-09

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory*. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan and the U. S. Department of Energy’s Office of Science. The RBRC is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has theory, lattice gauge computing and experimental components. It is presently exploring the possibility of an astrophysics component being added to the program. The purpose of this Workshop is to critically review the recent progress on the theory and phenomenology of early time dynamics in relativistic heavy ion collisions from RHIC to LHC energies, to examine the various approaches on thermalization and existing issues, and to formulate new research efforts for the future. Topics slated to be covered include Experimental evidence for equilibration/isotropization, comparison of various approaches, dependence on the initial conditions and couplings, and turbulent cascades and Bose-Einstein condensation.

  8. Nuclear suppression at large forward rapidities in d-Au collisions at relativistic and ultrarelativistic energies

    Science.gov (United States)

    Nemchik, J.; Petráček, V.; Potashnikova, I. K.; Šumbera, M.

    2008-08-01

    We study a strong suppression of the relative production rate (d-Au)/(p-p) for inclusive high-pT hadrons of different species at large forward rapidities (large Feynman xF). The model predictions calculated in the light-cone dipole approach are in a good agreement with the recent measurements by the BRAHMS and STAR Collaborations at the BNL Relativistic Heavy Ion Collider. We predict a similar suppression at large pT and large xF also at lower energies, where no effect of coherence is possible. This allows us to exclude the saturation models or the models based on Color Glass Condensate from interpretation of nuclear effects.

  9. Heavy flavor electron $R_\\text{AA}$ and $v_2$ in event-by-event relativistic hydrodynamics

    CERN Document Server

    Prado, Caio A G; Munhoz, Marcelo G; Noronha, Jorge; Suaide, Alexandre A P

    2015-01-01

    In this work we investigate how event-by-event hydrodynamics fluctuations affect the nuclear suppression factor and elliptic flow of heavy flavor mesons and non-photonic electrons. We use a 2D+1 Lagrangian ideal hydrodynamic code on an event-by-event basis in order to compute local temperature and flow profiles. Using a strong coupling inspired energy loss parametrization on top of the evolving space-time energy density distributions we are able to propagate the heavy quarks inside the medium until the freeze-out temperature is reached and a Pythia modeling of hadronization takes place. The resulting D$^0$ and heavy-flavor electron yield is compared with recent experimental data for $R_\\text{AA}$ and $v_2$ from the STAR and Phenix collaborations. In addition we present preditions for the higher order Fourier harmonic coefficients $v_3(p_T)$ of heavy-flavor electrons at RHIC's $\\sqrt{S_\\text{NN}} = 200$ GeV collisions.

  10. BNL ATF II beamlines design

    International Nuclear Information System (INIS)

    The Brookhaven National Laboratory. Accelerator Test Facility (BNL ATF) is currently undergoing a major upgrade (ATF-II). Together with a new location and much improved facilities, the ATF will see an upgrade in its major capabilities: electron beam energy and quality and CO2 laser power. The electron beam energy will be increased in stages, first to 100-150 MeV followed by a further increase to 500 MeV. Combined with the planned increase in CO2 laser power (from 1-100 TW), the ATF-II will be a powerful tool for Advanced Accelerator research. A high-brightness electron beam, produced by a photocathode gun, will be accelerated and optionally delivered to multiple beamlines. Besides the energy range (up to a possible 500 MeV in the final stage) the electron beam can be tailored to each experiment with options such as: small transverse beam size (<10 um), short bunch length (<100 fsec) and, combined short and small bunch options. This report gives a detailed overview of the ATFII capabilities and beamlines configuration.

  11. BNL Direct Wind Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  12. BWR stability analyses at BNL

    International Nuclear Information System (INIS)

    The March 9, 1988 instability at the LaSalle County-2 boiling water reactor power plant at Seneca, IL was simulated with Brookhaven National Laboratory's (BNL's) Engineering Plant Analyzer (EPA) for the purpose of demonstrating that the EPA is suitable for simulating large-amplitude, limit-cycle power and flow oscillations. It was shown in fall of 1988, by comparing all the available plant data from the STARTREC recording system of LaSalle-2 with EPA simulation results, that the EPA reproduces the LaSalle-2 oscillations without the use of stabilizing or destabilizing model or parameter modifications. The power vs. flow map of the LaSalle-2 plant was also reproduced at five lines of constant control rod positions. The LaSalle-2 stability boundary was established with the EPA and confirmed within ±15% accuracy by comparing the EPA results with the results of the frequency domain code LAPUR of Oak Ridge National Laboratory. Comparisons of EPA simulation results with plant data from three Peach Bottom stability tests show an agreement, based on mean and standard deviation, of -10±28%, -1±40% and +28±52% (low power) in the gain of the pressure to power transfer functions. This demonstrates that the time domain code HIPA in the EPA is capable of simulating instabilities

  13. BNL ATF II beamlines design

    Energy Technology Data Exchange (ETDEWEB)

    Fedurin, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Jing, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stratakis, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Swinson, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The Brookhaven National Laboratory. Accelerator Test Facility (BNL ATF) is currently undergoing a major upgrade (ATF-II). Together with a new location and much improved facilities, the ATF will see an upgrade in its major capabilities: electron beam energy and quality and CO2 laser power. The electron beam energy will be increased in stages, first to 100-150 MeV followed by a further increase to 500 MeV. Combined with the planned increase in CO2 laser power (from 1-100 TW), the ATF-II will be a powerful tool for Advanced Accelerator research. A high-brightness electron beam, produced by a photocathode gun, will be accelerated and optionally delivered to multiple beamlines. Besides the energy range (up to a possible 500 MeV in the final stage) the electron beam can be tailored to each experiment with options such as: small transverse beam size (<10 um), short bunch length (<100 fsec) and, combined short and small bunch options. This report gives a detailed overview of the ATFII capabilities and beamlines configuration.

  14. Application of independent component analysis to ac dipole based optics measurement and correction at the Relativistic Heavy Ion Collider

    Science.gov (United States)

    Shen, X.; Lee, S. Y.; Bai, M.; White, S.; Robert-Demolaize, G.; Luo, Y.; Marusic, A.; Tomás, R.

    2013-11-01

    Correction of beta-beat is of great importance for performance improvement of high energy accelerators, like the Relativistic Hadron Ion Collider (RHIC). At RHIC, using the independent component analysis method, linear optical functions are extracted from the turn by turn beam position data of the ac dipole driven betatron oscillation. Despite the constraint of a limited number of available quadrupole correctors at RHIC, a global beta-beat correction scheme using a beta-beat response matrix method was developed and experimentally demonstrated. In both rings, a factor of 2 or better reduction of beta-beat was achieved within available beam time. At the same time, a new scheme of using horizontal closed orbit bump at sextupoles to correct beta-beat in the arcs was demonstrated in the Yellow ring of RHIC at beam energy of 255 GeV, and a peak beta-beat of approximately 7% was achieved.

  15. 'Antigravity' Propulsion and Relativistic Hyperdrive

    CERN Document Server

    Felber, F S

    2006-01-01

    Exact payload trajectories in the strong gravitational fields of compact masses moving with constant relativistic velocities are calculated. The strong field of a suitable driver mass at relativistic speeds can quickly propel a heavy payload from rest to a speed significantly faster than the driver, a condition called hyperdrive. Hyperdrive thresholds and maxima are calculated as functions of driver mass and velocity.

  16. Bonding analysis using localized relativistic orbitals: water, the ultrarelativistic case and the heavy homologues H2X (X = Te, Po, eka-Po).

    Science.gov (United States)

    Dubillard, S; Rota, J-B; Saue, T; Faegri, K

    2006-04-21

    We report the implementation of Pipek-Mezey [J. Chem. Phys. 90, 4916 (1989)] localization of molecular orbitals in the framework of a four-component relativistic molecular electronic structure theory. We have used an exponential parametrization of orbital rotations which allows the use of unconstrained optimization techniques. We demonstrate the strong basis set dependence of the Pipek-Mezey localization criterion and how it can be eliminated. We have employed localization in conjunction with projection analysis to study the bonding in the water molecule and its heavy homologues. We demonstrate that in localized orbitals the repulsion between hydrogens in the water molecule is dominated by electrostatic rather than exchange interactions and that freezing the oxygen 2s orbital blocks polarization of this orbital rather than hybridization. We also point out that the bond angle of the water molecule cannot be rationalized from the potential energy alone due to the force term of the molecular virial theorem that comes into play at nonequilibrium geometries and which turns out to be crucial in order to correctly reproduce the minimum of the total energy surface. In order to rapidly assess the possible relativistic effects we have carried out the geometry optimizations of the water molecule at various reduced speed of light with and without spin-orbit interaction. At intermediate speeds, the bond angle is reduced to around 90 degrees , as is known experimentally for H(2)S and heavier homologues, although our model of ultrarelativistic water by construction does not allow any contribution from d orbitals to bonding. At low speeds of light the water molecule becomes linear which is in apparent agreement with the valence shell electron pair repulsion (VSEPR) model since the oxygen 2s12 and 2p12 orbitals both become chemically inert. However, we show that linearity is brought about by the relativistic stabilization of the (n + 1)s orbital, the same mechanism that leads to an

  17. Bonding analysis using localized relativistic orbitals: water, the ultrarelativistic case and the heavy homologues H2X (X = Te, Po, eka-Po).

    Science.gov (United States)

    Dubillard, S; Rota, J-B; Saue, T; Faegri, K

    2006-04-21

    We report the implementation of Pipek-Mezey [J. Chem. Phys. 90, 4916 (1989)] localization of molecular orbitals in the framework of a four-component relativistic molecular electronic structure theory. We have used an exponential parametrization of orbital rotations which allows the use of unconstrained optimization techniques. We demonstrate the strong basis set dependence of the Pipek-Mezey localization criterion and how it can be eliminated. We have employed localization in conjunction with projection analysis to study the bonding in the water molecule and its heavy homologues. We demonstrate that in localized orbitals the repulsion between hydrogens in the water molecule is dominated by electrostatic rather than exchange interactions and that freezing the oxygen 2s orbital blocks polarization of this orbital rather than hybridization. We also point out that the bond angle of the water molecule cannot be rationalized from the potential energy alone due to the force term of the molecular virial theorem that comes into play at nonequilibrium geometries and which turns out to be crucial in order to correctly reproduce the minimum of the total energy surface. In order to rapidly assess the possible relativistic effects we have carried out the geometry optimizations of the water molecule at various reduced speed of light with and without spin-orbit interaction. At intermediate speeds, the bond angle is reduced to around 90 degrees , as is known experimentally for H(2)S and heavier homologues, although our model of ultrarelativistic water by construction does not allow any contribution from d orbitals to bonding. At low speeds of light the water molecule becomes linear which is in apparent agreement with the valence shell electron pair repulsion (VSEPR) model since the oxygen 2s12 and 2p12 orbitals both become chemically inert. However, we show that linearity is brought about by the relativistic stabilization of the (n + 1)s orbital, the same mechanism that leads to an

  18. Heavy flavor $R_\\text{AA}$ and $v_n$ in event-by-event viscous relativistic hydrodynamics

    CERN Document Server

    Prado, Caio A G; Cosentino, Mauro R; Munhoz, Marcelo G; Noronha, Jorge; Suaide, Alexandre A P

    2016-01-01

    Recently it has been shown that a realistic description of the medium via event-by-event viscous hydrodynamics plays an important role in the long-standing $R_\\text{AA}$ vs. $v_2$ puzzle at high $p_T$. In this proceedings we begin to extend this approach to the heavy flavor sector by investigating the effects of full event-by-event fluctuating hydrodynamic backgrounds on the nuclear suppression factor and $v_2\\{2\\}$ of heavy flavor mesons and non-photonic electrons at intermediate to high $p_T$. We also show results for $v_3\\{2\\}$ of $B^0$ and D$^0$ for PbPb collisions at $\\sqrt{s}=2.76$ TeV.

  19. First test of BNL electron beam ion source with high current density electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, Alexander, E-mail: pikin@bnl.gov; Alessi, James G., E-mail: pikin@bnl.gov; Beebe, Edward N., E-mail: pikin@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); Shornikov, Andrey; Mertzig, Robert; Wenander, Fredrik; Scrivens, Richard [CERN, CH-1211 Geneva 23 (Switzerland)

    2015-01-09

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm{sup 2} and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given.

  20. First test of BNL electron beam ion source with high current density electron beam

    International Nuclear Information System (INIS)

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm2 and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given

  1. Highlights from BNL-RHIC-2012

    CERN Document Server

    Tannenbaum, M J

    2013-01-01

    Recent highlights from Brookhaven National Laboratory and the Relativistic Heavy Ion Collider (RHIC) are reviewed and discussed in the context of the discovery of the strongly interacting Quark Gluon Plasma (sQGP) at RHIC in 2005 as confirmed by results from the CERN-LHC Pb+Pb program. Outstanding RHIC machine operation in 2012 with 3-dimensional stochastic cooling and a new EBIS ion source enabled measurements with Cu+Au, U+U, for which multiplicity distributions are shown, as well as with polarized p-p collisions. Differences of the physics and goals of p-p versus A+A are discussed leading to a review of RHIC results on pi0 suppression in Au+Au collisions and comparison to LHC Pb+Pb results in the same range 5 30 GeV. Improved measurements of direct photon production and correlation with charged particles at RHIC are shown, including the absence of a low pT (thermal) photon enhancement in d+Au collisions. Attempts to understand the apparent equality of the energy loss of light and heavy quarks in the QGP by...

  2. Probing the direct step of relativistic heavy ion fragmentation: (12C, 11B+p) at 2.1 GeV/nucleon with C and CH2 targets

    International Nuclear Information System (INIS)

    Relativistic heavy ion collisions may be classified as central (and near central), peripheral, and grazing with each collision type producing different proton and other charged projectile fragment scattering mechanisms and characteristics. This report focuses on peripheral and grazing collisions in the fragmentation of Carbon-12 into Boron-11 and a proton, testing models of the kinetics involved in this reaction. The data were measured at the Heavy Ion Superconducting Spectrometer (HISS) at Lawrence Berkeley Laboratory and include excitation energy for the p/Boron-11 pair, and rapidity versus transverse momentum for protons and Boron-11. 58 refs., 35 figs., 8 tabs

  3. Possible effect of mixed phase and deconfinement upon spin correlations in the \\Lambda\\bar{\\Lambda} pairs generated in relativistic heavy-ion collisions

    Science.gov (United States)

    Lyuboshitz, Valery V.; Lyuboshitz, Vladimir L.

    2016-01-01

    Spin correlations for the ΛΛ and Λ\\barΛ pairs, generated in relativistic heavy-ion collisions, and related angular correlations at the joint registration of hadronic decays of two hyperons, in which space parity is not conserved, are analyzed. The correlation tensor components can be derived from the double angular distribution of products of two decays by the method of “moments”. The properties of the “trace” of the correlation tensor (a sum of three diagonal components), determining the relative fractions of the triplet states and singlet state of respective pairs, are discussed. Spin correlations for two identical particles (ΛΛ) and two non-identical particles (Λ\\barΛ ) are considered from the viewpoint of the conventional model of one-particle sources. In the framework of this model, correlations vanish at sufficiently large relative momenta. However, under these conditions, in the case of two non-identical particles (Λ\\barΛ ) a noticeable role is played by two-particle annihilation (two-quark, two-gluon) sources, which lead to the difference of the correlation tensor from zero. In particular, such a situation may arise when the system passes through the “mixed phase”.

  4. New experimental results obtained in Au-Au collisions at the energies available to the RHIC-BNL using BRAHMS experimental setup

    International Nuclear Information System (INIS)

    Many experimental data for Au-Au collisions at √sNN = 130 GeV and √sNN = 200 GeV have been obtained in the last two years at the Relativistic Heavy Ion Collider (RHIC) from Brookhaven National Laboratory, Upton, New York, USA. The experimental setup BRAHMS is one of the five experimental setups used at RHIC-BNL. Interesting experimental results on many physical quantities with dynamic signification have been obtained. In the present work we report the new results on charged particle multiplicities, pseudorapidities, rapidities, transverse, momentum spectra, and particle to antiparticle ratios. These experimental results lead to nuclear temperatures and nuclear densities at different collision centralities and rapidities. Some interesting results on collective flow velocities of the nuclear matter are also obtained. Dependencies on the collision centrality, pseudorapidity and beam energy, in the center-of-mass system, are included in the work. The highest multiplicities (more than 5000 charged particles per event) and the highest pionic, kaonic and protonic temperatures obtained up to now are reported for the most central collisions (0-6%). The Coulomb effects are very low at very small velocities. A significant increase of the negative kaon to positive kaon ratio appears at rapidities around y = 0.0. Similar results are obtained for antiproton to proton ratio. The stopping of the nuclear matter is reflected by the high collective velocities obtained in the same rapidity range (up to 0.6 c). All these experimental results, as well as the experimental results obtained in the frame of other collaborations, including the RHIC-BNL collaboration, will be used to obtain new information on the behaviour of the highly excited and dense nuclear matter and the formation conditions for the quark-gluon plasma. Interesting information on the Universe behaviour in the first microsecond after Big Bang can also be obtained. (authors)

  5. PROCEEDINGS OF RIKIN BNL RESEARCH CENTER WORKSHOP - VOLUME 79

    Energy Technology Data Exchange (ETDEWEB)

    SAMIOS,N.

    2006-02-16

    Since the earliest days of ultra-relativistic heavy ion physics, there has been interest in strange particle production. Originally, an anomalously large strangeness production was believed to be a signature of the Quark Gluon Plasma. Now the flavor composition of the plasma as reflected in the ratios of abundances of strange and non-strange particles is believed by advocates to tell us the temperature and baryon number density of the Quark Gluon Plasma at decoupling. In addition, there are arguments that suggest that the abundances of strange particles might at intermediate energy or at non-central rapidity, signal the existence of a critical end point of phase transitions in the baryon number chemical potential temperature plane. The purpose of this workshop is to assess the current theoretical and experimental understanding of strangeness production for ultra-relativistic heavy ion collisions.

  6. Quark-gluon plasma: Status of heavy ion physics

    Indian Academy of Sciences (India)

    R V Gavai

    2000-07-01

    Lattice quantum chromodynamics (QCD), defined on a discrete space–time lattice, leads to a spectacular non-perturbative prediction of a new state of matter, called quark-gluon plasma (QGP), at sufficiently high temperatures or equivalently large energy densities. The experimental programs of CERN, Geneva and BNL, New York of relativistic heavy ion collisions are expected to produce such energy densities, thereby providing us a chance to test the above prediction. After a brief introduction of the necessary theoretical concepts, I will present a critical review of the experimental results already obtained by the various experiments in order to examine whether QGP has already been observed by them.

  7. Predictions for the heavy-ion programme at the Large Hadron Collider

    CERN Document Server

    Armesto, N

    2010-01-01

    I review the main predictions for the heavy-ion programme at the Large Hadron Collider (LHC) at CERN, as available in early March 2009. I begin by remembering the standard claims made in view of the experimental data measured at the Super Proton Synchrotron (SPS) at CERN and at the Relativistic Heavy Ion Collider (RHIC) at the BNL. These claims will be used for later discussion of the new opportunities at the LHC. Next I review the generic, qualitative expectations for the LHC. Then I turn to quantitative predictions: First I analyze observables which characterize directly the medium produced in the collisions - bulk observables or soft probes -: multiplicities, collective flow, hadrochemistry at low transverse momentum, correlations and fluctuations. Second, I move to calibrated probes of the medium i.e. typically those whose expectation in the absence of any medium can be described in Quantum Chromodynamics (QCD) using perturbative techniques (pQCD), usually called hard probes. I discuss particle production...

  8. Core - Corona Model analysis of the Low Energy Beam Scan at RHIC (Relativistic Heavy Ion Collider) in Brookhaven (USA)

    CERN Document Server

    Gemard, M

    2014-01-01

    The centrality dependence of spectra of identified particles in collisions between ultrarelativistic heavy ions with a center of mass energy ($\\sqrt{s}$) of 39 and 11.5 $AGeV$ is analyzed in the core - corona model. We show that at these energies the spectra can be well understood assuming that they are composed of two components whose relative fraction depends on the centrality of the interaction: The core component which describes an equilibrated quark gluon plasma and the corona component which is caused by nucleons close to the surface of the interaction zone which scatter only once and which is identical to that observed in proton-proton collisions. The success of this approach at 39 and 11.5 $AGeV$ shows that the physics does not change between this energy and $\\sqrt{s}=200~ AGeV$ for which this model has been developed (Aichelin 2008). This presents circumstantial evidence that a quark gluon plasma is also created at center of mass energies as low as 11.5 $AGeV$.

  9. 2013 BNL Site Environmental Report. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Ratel, K.; Remien, J.; Pohlot, P.; Williams, J.; Green, T.; Paquette, P.; Dorsch, W.; Welty, T.; Burke, J.

    2014-10-01

    A summary of Brookhaven National Laboratory’s (BNL) Site Environmental Report, meant to inform the public, regulators, employees, and other stakeholders of the Laboratory’s environmental performance in the lab’s surrounding area during the calendar year. The review is comprised of multiple volumes relevant to environmental data/environmental management performance and groundwater status report.

  10. Intriguing structures and magic sizes of heavy noble metal nanoclusters around size 55 governed by relativistic effect and covalent bonding

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, X. J.; Xue, X. L.; Jia, Yu [International Laboratory for Quantum Functional Materials of Henan and School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001 (China); Guo, Z. X. [International Laboratory for Quantum Functional Materials of Henan and School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001 (China); Department of Chemistry and London Centre for Nanotechnology, University College London, London WC1H (United Kingdom); Li, S. F., E-mail: sflizzu@zzu.edu.cn [International Laboratory for Quantum Functional Materials of Henan and School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001 (China); ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Zhenyu, E-mail: zhangzy@ustc.edu.cn [ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Gao, Y. F., E-mail: ygao7@utk.edu [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2015-11-07

    Nanoclusters usually display exotic physical and chemical properties due to their intriguing geometric structures in contrast to their bulk counterparts. By means of first-principles calculations within density functional theory, we find that heavy noble metal Pt{sub N} nanoclusters around the size N = 55 begin to prefer an open configuration, rather than previously reported close-packed icosahedron or core-shell structures. Particularly, for Pt{sub N}, the widely supposed icosahedronal magic cluster is changed to a three-atomic-layered structure with D{sub 6h} symmetry, which can be well addressed by our recently established generalized Wulff construction principle (GWCP). However, the magic number of Pt{sub N} clusters around 55 is shifted to a new odd number of 57. The high symmetric three-layered Pt{sub 57} motif is mainly stabilized by the enhanced covalent bonding contributed by both spin-orbital coupling effect and the open d orbital (5d{sup 9}6s{sup 1}) of Pt, which result in a delicate balance between the enhanced Pt–Pt covalent bonding of the interlayers and negligible d dangling bonds on the cluster edges. These findings about Pt{sub N} clusters are also applicable to Ir{sub N} clusters, but qualitatively different from their earlier neighboring element Os and their later neighboring element Au. The magic numbers for Os and Au are even, being 56 and 58, respectively. The findings of the new odd magic number 57 are the important supplementary of the recently established GWCP.

  11. HOM absorbers for ERL cryomodules at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Hahn,H.; Ben-Zvi, I.; Hammons, L.; Xu, W.

    2009-09-20

    The physics needs and technical requirements for several future accelerator projects at the Relativistic Heavy Ion Collider (RHIC) all involve electron Energy Recovery Linacs (ERL). The required high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory and the development of HOM dampers for a prototypical five-cell cavity is actively pursued. An experimental five-cell niobium cavity with ferrite dampers has been constructed, and effective HOM damping has been demonstrated at room and superconducting (SC) temperatures. A novel type of ferrite damper around a ceramic break has been developed for the ERL electron gun and prototype tests are also reported. Contemplated future projects are based on assembling a chain of superconducting cavities in a common cryomodule with the dampers placed in the cold space between the cavities, imposing severe longitudinal space constraints. Various damper configurations have been studied by placing them between two five-cell copper cavities. Measured and simulated copper cavity results, external Q-values of possible dampers and fundamental mode losses are presented.

  12. Relativistic uranium beams - the Bevalac experience

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, J.

    1983-03-01

    This paper will address areas where relativistic heavy ion accelerators differ from proton facilities. Salient areas are: (1) the specialized injectors for heavy ions; ion sources, structures for very low charge-to-mass ratio (q/A) ions, and stripper optimization; (2) special requirements for the synchrotron ring; ultrahigh vacuum, flexible controls and instrumentation. These areas are discussed in the context of the Bevalac, as well as our idea for a next-generation relativistic heavy ion accelerator.

  13. Di-jet conical correlations associated with heavy quark jets in anti-de sitter space/conformal field theory correspondence.

    Science.gov (United States)

    Noronha, Jorge; Gyulassy, Miklos; Torrieri, Giorgio

    2009-03-13

    We show that far zone Mach and diffusion wake "holograms" produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict N_{c}-->infinity supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium "neck" zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence. PMID:19392107

  14. Di-Jet Conical Correlations Associated with Heavy Quark Jets in anti-de Sitter Space/Conformal Field Theory Correspondence

    International Nuclear Information System (INIS)

    We show that far zone Mach and diffusion wake 'holograms' produced by supersonic strings in anti-de Sitter space/conformal field theory (AdS/CFT) correspondence do not lead to observable conical angular correlations in the strict Nc→∞ supergravity limit if Cooper-Frye hadronization is assumed. However, a special nonequilibrium 'neck' zone near the jet is shown to produce an apparent sonic boom azimuthal angle distribution that is roughly independent of the heavy quark's velocity. Our results indicate that a measurement of the dependence of the away-side correlations on the velocity of associated identified heavy quark jets at the BNL Relativistic Heavy Ion Collider and CERN LHC will provide a direct test of the nonperturbative dynamics involved in the coupling between jets and the strongly coupled quark-gluon plasma implied by AdS/CFT correspondence

  15. Anomalous transport model study of chiral magnetic effects in heavy ion collisions

    Science.gov (United States)

    Sun, Yifeng; Ko, Che Ming; Li, Feng

    2016-10-01

    Using an anomalous transport model for massless quarks and antiquarks, we study the effect of a magnetic field on the elliptic flows of quarks and antiquarks in relativistic heavy ion collisions. With initial conditions from a blast wave model and assuming that the strong magnetic field produced in noncentral heavy ion collisions can last for a sufficiently long time, we obtain an appreciable electric quadrupole moment in the transverse plane of a heavy ion collision. The electric quadrupole moment subsequently leads to a splitting between the elliptic flows of quarks and antiquarks. The slope of the charge asymmetry dependence of the elliptic flow difference between positively and negatively charged particles is positive, which is expected from the chiral magnetic wave formed in the produced QGP and observed in experiments at the BNL Relativistic Heavy Ion Collider, only if the Lorentz force acting on the charged particles is neglected and the quark-antiquark scattering is assumed to be dominated by the chirality changing channel.

  16. Relativistic astrophysics

    CERN Document Server

    Demianski, Marek

    2013-01-01

    Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity

  17. Relativistic EOS for supernova simulations

    OpenAIRE

    Shen H

    2014-01-01

    We study the relativistic equation of state (EOS) of dense matter covering a wide range of temperature, proton fraction, and baryon density for the use of supernova simulations. This work is based on the relativistic mean-field theory (RMF) and the Thomas-Fermi approximation. The Thomas-Fermi approximation in combination with assumed nucleon distribution functions and a free energy minimization is adopted to describe the non-uniform matter, which is composed of a lattice of heavy nuclei. We t...

  18. PHENIX Spinfest School 2009 at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Foster,S.P.; Foster,S.; Seidl, R.; Goto, Y.; Okada, K.

    2009-08-07

    Since 2005, the PHENIX Spin Physics Working Group has set aside several weeks each summer for the purposes of training and integrating recent members of the working group as well as coordinating and making rapid progress on support tasks and data analysis. One week is dedicated to more formal didactic lectures by outside speakers. The location has so far alternated between BNL and the RIKEN campus in Wako, Japan, with support provided by RBRC and LANL.

  19. Simulation of a relativistic heavy ions beam transport in the matter: contribution of the fragmentation process and biological implications; Simulation du transport d`un faisceau d`ions lourds relativistes dans la matiere: contribution du processus de fragmentation et implication sur le plan biologique

    Energy Technology Data Exchange (ETDEWEB)

    Ibnouzahir, M.

    1995-03-01

    The study of relativistic heavy ion collisions permit an approach of the properties of dense and not hadronic matter, and an analysis of the reaction mechanisms. Such studies are also interesting on the biological point of view, since there exist now well defined projects concerning the radiotherapy with high LET particles as neutrons, protons, heavy ions. It is thus necessary to have a good understanding of the processes which occur in the propagation of a relativistic heavy ion beam (E{>=} 100 A.MeV) in matter. We have elaborated a three dimensional transport code, using a Monte Carlo method, in order to describe the propagation of Ne and Ar ions in water. Violent nuclear collisions giving fragmentation process have been taken into account by use of the FREESCO program. We have tested the validity of our transport model and we show an important change of the energy deposition at the vicinity of the Bragg peak; such a distortion, due mainly to fragmentation reactions, is of a great interest for biological applications. (author).

  20. BNL ENVIRONMENTAL MONITORING PLAN TRIENNIAL UPDATE, JANUARY 2003.

    Energy Technology Data Exchange (ETDEWEB)

    BROOKHAVEN NATIONAL LABORATORY

    2003-01-01

    Brookhaven National Laboratory (BNL) is a multi-program national laboratory operated by Brookhaven Science Associates for the U.S. Department of Energy (DOE) and is located on a 5,265-acre site in Suffolk County, Long Island, New York. BNL has a comprehensive Environmental Management System (EMS) in place, which meets the requirements of the International Organization for Standardization 14001 EMS Standard, as described in the BNL EMS Manual. BNL's extensive environmental monitoring program is one component of the EMS, and the BNL Environmental Monitoring Plan (EMP) describes this program in detail. The data derived from systematically monitoring the various environmental media on site enable BNL to make informed decisions concerning the protection of human health and the environment and to be responsive to community concerns.

  1. BNl 703 MHz superconducting RF cavity testing

    Energy Technology Data Exchange (ETDEWEB)

    Sheehy, B.; Altinbas, Z.; Burrill, A.; Ben-Zvi, I.; Gassner, D.; Hahn, H.; Hammons, L.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Laloudakis, N.; Lederle, D.; Litvinenko, V.; McIntyre, G.; Pate, D.; Phillips, D.; Schultheiss, C.; Seda,T.; Than, R.; Xu, W.; Zaltsman, A.; Schultheiss, T.

    2011-03-28

    The BNL 5-cell, 703 MHz superconducting accelerating cavity has been installed in the high-current ERL experiment. This experiment will function as a proving ground for the development of high-current machines in general and is particularly targeted at beam development for an electron-ion collider (eRHIC). The cavity performed well in vertical tests, demonstrating gradients of 20 MV/m and a Q{sub 0} of 1e10. Here we will present its performance in the horizontal tests, and discuss technical issues involved in its implementation in the ERL.

  2. OPERATIONS ELECTRONIC LOGBOOK EXPERIENCE AT BNL.

    Energy Technology Data Exchange (ETDEWEB)

    SATOGATA,T.; CAMPBELL,I.; MARR,G.; SAMPSON,P.

    2002-06-02

    A web-based system for electronic logbooks, ''elog'', developed at Fermilab (FNAL), has been adopted for use by AGS and RHIC operations and physicists at BNL for the 2001-2 fixed target and collider runs. This paper describes the main functional and technical issues encountered in the first year of electronic logbook use, including security, search and indexing, sequencer integration, archival, and graphics management. We also comment on organizational experience and planned changes for the next facility run starting in September 2002.

  3. Analytic solution for relativistic transverse flow at the softest point

    CERN Document Server

    Biro, T S

    2000-01-01

    We obtain an extension of Bjorken's 1+1 dimensional scaling relativistic flow solution to relativistic transverse velocities with cylindrical symmetry in 1+3 dimensions at constant, homogeneous pressure (vanishing sound velocity). This can be the situation during a first order phase transition converting quark matter into hadron matter in relativistic heavy ion collisions.

  4. Relativistic shell model calculations

    Science.gov (United States)

    Furnstahl, R. J.

    1986-06-01

    Shell model calculations are discussed in the context of a relativistic model of nuclear structure based on renormalizable quantum field theories of mesons and baryons (quantum hadrodynamics). The relativistic Hartree approximation to the full field theory, with parameters determined from bulk properties of nuclear matter, predicts a shell structure in finite nuclei. Particle-hole excitations in finite nuclei are described in an RPA calculation based on this QHD ground state. The particle-hole interaction is prescribed by the Hartree ground state, with no additional parameters. Meson retardation is neglected in deriving the RPA equations, but it is found to have negligible effects on low-lying states. The full Dirac matrix structure is maintained throughout the calculation; no nonrelativistic reductions are made. Despite sensitive cancellations in the ground state calculation, reasonable excitation spectra are obtained for light nuclei. The effects of including charged mesons, problems with heavy nuclei, and prospects for improved and extended calculations are discussed.

  5. Local Relativistic Exact Decoupling

    CERN Document Server

    Peng, Daoling

    2012-01-01

    We present a systematic hierarchy of approximations for {\\it local} exact-decoupling of four-component quantum chemical Hamiltonians based on the Dirac equation. Our ansatz reaches beyond the trivial local approximation that is based on a unitary transformation of only the atomic block-diagonal part of the Hamiltonian. Systematically, off-diagonal Hamiltonian matrix blocks can be subjected to a unitary transformation to yield relativistically corrected matrix elements. The full hierarchy is investigated with respect to the accuracy reached for the electronic energy and molecular properties on a balanced test molecule set that comprises molecules with heavy elements in different bonding situations. Our atomic (local) assembly of the unitary transformation needed for exact decoupling provides an excellent local approximation for any relativistic exact-decoupling approach. Its order-$N^2$ scaling can be further reduced to linear scaling by employing the neighboring-atomic-blocks approximation. Therefore, it is a...

  6. Dynamics of relativistic jets

    Science.gov (United States)

    Nishikawa, K.-I.; Frank, J.; Christodoulou, D. M.; Koide, S.; Sakai, J.-I.; Sol, Hélène; Mutel, Robert L.

    1998-12-01

    We discuss the structure and relativistic kinematics that develop in three spatial dimensions when a moderately hot, supersonic jet propagates into a denser background medium and encounters resistance from an oblique magnetic field. Our simulations incorporate relativistic MHD in a four-dimensional spacetime and clearly show that (a) relatively weak, oblique fields (at 1/16 of the equipartition value) have only a negligible influence on the propagating jet and they are passively pushed away by the relativistically moving head; (b) oblique fields in equipartition with the ambient plasma provide more resistance and cause bending at the jet head, but the magnitude of this deflection and the associated backflow are small compared to those identified by previous studies. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently during the simulations. The effect is analogous to pushing Japanese "noren" or vertical Venetian blinds out of the way while the slats are allowed to bend and twist in 3-D space. Applied to relativistic extragalactic jets from blazars, the new results are encouraging since superluminal outflows exhibit bending near their sources and their environments are profoundly magnetized - but observations do not provide support for irregular kinematics such as large-scale vortical motions and pronounced reverse flows near the points of origin.

  7. Relativistic hydrodynamics

    CERN Document Server

    Luciano, Rezzolla

    2013-01-01

    Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...

  8. Emergency response training with the BNL plant analyzer

    International Nuclear Information System (INIS)

    Presented in the experience in the use of the BNL plant analyzer for NRC emergency response training to simulated accidents in a BWR. The unique features of the BNL Plant Analyzer that are important for the emergency response training are summarized. A closed-loop simulation of all the key systems of a power plant in question was found essential to the realism of the emergency drills conducted at NRC. The faster than real-time simulation speeds afforded by the BNL Plant Analyzer have demonstrated its usefulness for the timely conduct of the emergency response training

  9. Strange hadrons and antiprotons as probes of hot and dense nuclear matter in relativistic heavy-ion collisions; Seltsame Hadronen und Antiprotonen als Proben heisser und dichter Kernmaterie in relativistischen Schwerionenkollisionen

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Henry

    2010-09-15

    Strange particles play an important role as probes of relativistic heavy-ion collisions where hot and dense matter is studied. The focus of this thesis is on the production of strange particles within a transport model of Boltzmann-Uehling-Uhlenbeck (BUU) type. Current data of the HADES Collaboration concerning K{sup {+-}} and {phi} spectra provide the appropriate experimental framework. Moreover, the double-strange hyperon {xi}{sup -} is analyzed below the free NN production threshold. Hadron multiplicities, transversemomentum and rapidity spectra are compared with recent experimental data. Further important issues are in-medium mass shifts, the nuclear equation of state as well as the mean field of nucleons. Besides the study of AA collisions a comparison with recent ANKE data regarding the {phi} yield in pA collisions is done. Transparency ratios are determined and primarily investigated for absorption of {phi} mesons by means of the BUU transport code. Thereby, secondary {phi} production channels, isospin asymmetry and detector acceptance are important issues. A systematic analysis is presented for different system sizes. The momentum integrated Boltzmann equations describe dense nuclear matter on a hadronic level appearing in the Big Bang as well as in little bangs, in the context of kinetic off-equilibrium dynamics. This theory is applied to antiprotons and numerically calculated under consideration of various expansion models. Here, the evolution of proton- and antiproton densities till freeze-out is analyzed for ultra-relativistic heavy-ion collisions within a hadrochemic resonance gas model acting as a possible ansatz for solving the ''antiproton puzzle''. Furthermore, baryonic matter and antimatter is investigated in the early universe and the adiabatic path of cosmic matter is sketched in the QCD phase diagram. (orig.)

  10. Relativistic Kinematics

    CERN Document Server

    Sahoo, Raghunath

    2016-01-01

    This lecture note covers Relativistic Kinematics, which is very useful for the beginners in the field of high-energy physics. A very practical approach has been taken, which answers "why and how" of the kinematics useful for students working in the related areas.

  11. Relativistic EOS for supernova simulations

    Directory of Open Access Journals (Sweden)

    Shen H.

    2014-03-01

    Full Text Available We study the relativistic equation of state (EOS of dense matter covering a wide range of temperature, proton fraction, and baryon density for the use of supernova simulations. This work is based on the relativistic mean-field theory (RMF and the Thomas-Fermi approximation. The Thomas-Fermi approximation in combination with assumed nucleon distribution functions and a free energy minimization is adopted to describe the non-uniform matter, which is composed of a lattice of heavy nuclei. We treat the uniform matter and non-uniform matter consistently using the same RMF theory. We compare the EOS tables in detail.

  12. Heavy Quark Dynamics in Heavy Ion Reactions

    OpenAIRE

    Nagle, J. L.

    2003-01-01

    Collisions between heavy nuclei at the Relativistic Heavy Ion Collider liberate from the nuclear wavefunction of order 10,000 gluons, quarks and antiquarks. The system is dominated by gluons and up and down (anti) quarks. Heavy quarks, though having little effect on the overall equation of state, are critical as probes of the surrounding medium. We compare predictions from a scenario where the charm quarks escape the medium unaffected and fragment into hadrons in vacuum, and one where the cha...

  13. Radionuclide production and radiopharmaceutical chemistry with BNL cyclotrons

    International Nuclear Information System (INIS)

    The Brookhaven National Laboratory (BNL) radiopharmaceutical chemistry program focuses on production and utilization of radionuclides having a half-life of > 2 hr. However, a major portion of the BNL program is devoted to short-lived radionuclides, such as 11C and 18F. Activities encompassed in the program are classified into seven areas: cyclotron parameters, radiochemistry, design and rapid synthesis of radiopharmaceuticals and labeled compounds, radiotracer evaluation in animals, studies in humans, technology transfer, and several other areas

  14. Exposure of Plastic Track Detectors to Relativistic Pb Beam for the Purpose of Providing Calibration for the DUBLIN-ESTEC Ultra Heavy Cosmic Ray Experiment Which was Exposed for Sixty-Nine Months in Earth Orbit

    CERN Multimedia

    2002-01-01

    % WA100 \\\\ \\\\ Solid state nuclear track detectors which formed part of the Dublin-ESTEC ultra heavy~cosmic~ray experiment aboard LDEF (Long Duration Exposure Facility) and which was deployed in Earth orbit for sixty-nine months, will be exposed to relativistic Pb ions. The experiment was the largest of its kind ever undertaken in space and has successfully accumulated more than fifteen times the world sample of cosmic ray nuclei in the region above Z~=~70. The data include the first significant sample of cosmic ray actinide elements and is of major astrophysical importance. The total number of ultra heavy nuclei (Z~$>$~70) in the Dublin-ESTEC sample is $\\sim$~2800. \\\\ \\\\The exposure will be very simple. A stack of detectors (20.5~cm~x~26~cm x~3~cm in size) will be irradiated with a low density beam of Pb ions (a few hundred per cm$^2$ would be ideal, but a wide range of densities and areas could be tolerated). The response of the detectors to these ions of known charge and velocity will be measured and the da...

  15. Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD project. Proceedings of RIKEN BNL Research Center workshop: Volume 13

    International Nuclear Information System (INIS)

    A workshop was held at the RIKEN-BNL Research Center on October 16, 1998, as part of the first anniversary celebration for the center. This meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. Many of the talks in the workshop were devoted to domain wall fermions, a discretization of the continuum description of fermions which preserves the global symmetries of the continuum, even at finite lattice spacing. This formulation has been the subject of analytic investigation for some time and has reached the stage where large-scale simulations in QCD seem very promising. With the computational power available from the QCDSP computers, scientists are looking forward to an exciting time for numerical simulations of QCD

  16. Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD project. Proceedings of RIKEN BNL Research Center workshop: Volume 13

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-16

    A workshop was held at the RIKEN-BNL Research Center on October 16, 1998, as part of the first anniversary celebration for the center. This meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. Many of the talks in the workshop were devoted to domain wall fermions, a discretization of the continuum description of fermions which preserves the global symmetries of the continuum, even at finite lattice spacing. This formulation has been the subject of analytic investigation for some time and has reached the stage where large-scale simulations in QCD seem very promising. With the computational power available from the QCDSP computers, scientists are looking forward to an exciting time for numerical simulations of QCD.

  17. Calibration of the Heavy Flavor Tracker (HFT) detector in star experiment at RHIC

    Science.gov (United States)

    Alanazi, Norah

    This project is in the area of Relativistic Nuclear collisions and the commissioning of a new silicon vertex detector, the Heavy Flavor Tracker (HFT) in the STAR experiment at Brookhaven National Laboratory (BNL). BNL hosts RHIC, the Relativistic Heavy Ion Collider, the world's most advanced dedicated heavy ion and polarized proton accelerator facility. Heavy Ion collisions at RHIC provide a unique probe into the understanding of several aspects of the behavior of nuclear, i.e. strongly inter- acting, matter. Among the many insights that can be provided is the description of parton interaction inside the hot and dense medium produced in the early stages of a collision. It also allows us to search for evidence for a phase transition in nuclear matter, a phase where partons [quarks and gluons] can move freely over an extended volume. Production of heavy quarks in high-energy nuclear collisions at RHIC occurs mainly during the initial collisions where energetic gluon and quark interactions can create heavy quarks. Thus, heavy flavor provides an ideal probe in studying the hot and dense medium created in the early phases of high-energy nuclear collisions. A detailed study of heavy flavor is essential to better understand the parton dynamics and select among competing theoretical approaches, however, precise measurements of heavy flavor are difficult to obtain due to relatively low production rates and short lifetimes of heavy flavor hadrons. The combinatorial background in nuclear collisions makes the measurement of heavy flavor a challenging task. One approach to dramatically reduce the combinatorial background by several orders of magnitude is to separate the heavy-flavor hadron's decay vertex from the background. This is done with the help of high resolution vertex detectors. The Heavy Flavor Tracker upgrade for the STAR experiment, which made its debut during the year 2014 RHIC run (Run14), greatly improved the experiment's track pointing capabilities making STAR

  18. Relativistic geodesy

    Science.gov (United States)

    Flury, J.

    2016-06-01

    Quantum metrology enables new applications in geodesy, including relativistic geodesy. The recent progress in optical atomic clocks and in long-distance frequency transfer by optical fiber together pave the way for using measurements of the gravitational frequency redshift for geodesy. The remote comparison of frequencies generated by calibrated clocks will allow for a purely relativistic determination of differences in gravitational potential and height between stations on Earth surface (chronometric leveling). The long-term perspective is to tie potential and height differences to atomic standards in order to overcome the weaknesses and inhomogeneity of height systems determined by classical spirit leveling. Complementarily, gravity measurements with atom interferometric setups, and satellite gravimetry with space borne laser interferometers allow for new sensitivities in the measurement of the Earth's gravity field.

  19. Review: BNL graphite blanket design concepts

    International Nuclear Information System (INIS)

    A review of the Brookhaven National Laboratory (BNL) minimum activity graphite blanket designs is made. Three designs are identified and discussed in the context of an experimental power reactor (EPR) and commercial power reactor. Basically, the three designs employ a thick graphite screen (typically 30 cm or greater, depending on type as well as application-experimental power reactor or commercial reactor). Bremsstrahlung energy is deposited on the graphite surface and re-radiated away as thermal radiation. Fast neutrons are slowed down in the graphite, depositing most of their energy. This energy is then either radiated to a secondary blanket with coolant tubes, as in types A and B, or is removed by intermittent direct gas cooling (type C). In types A and B, radiation damage to the structural material of the coolant tubes in the secondary blanket is reduced by one or two orders of magnitude by the graphite screen, while in type C, the blanket is only cooled when the reactor is shut down, so that coolant cannot quench the plasma, whatever the degree of radiation damage

  20. BNL ALARA Center: ALARA Notes, No. 9

    Energy Technology Data Exchange (ETDEWEB)

    Khan, T.A.; Xie, J.W.; Beckman, M.C. [eds.] [and others

    1994-02-01

    This issue of the Brookhaven National Laboratory`s Alara Notes includes the agenda for the Third International Workshop on ALARA and specific instructions on the use of the on-line fax-on-demand service provided by BNL. Other topics included in this issue are: (1) A discussion of low-level discharges from Canadian nuclear plants, (2) Safety issues at French nuclear plants, (3) Acoustic emission as a means of leak detection, (4) Replacement of steam generators at Doel-3, Beaznau, and North Anna-1, (5) Remote handling equipment at Bruce, (6) EPRI`s low level waste program, (7) Radiation protection during concrete repairs at Savannah River, (8) Reactor vessel stud removal/repair at Comanche Peak-1, (9) Rework of reactor coolant pump motors, (10) Restoration of service water at North Anna-1 and -2, (11) Steam generator tubing problems at Mihama-1, (12) Full system decontamination at Indian Point-2, (13) Chemical decontamination at Browns Ferry-2, and (14) Inspection methodolody in France and Japan.

  1. BNL ALARA Center: ALARA Notes, No. 9

    International Nuclear Information System (INIS)

    This issue of the Brookhaven National Laboratory's Alara Notes includes the agenda for the Third International Workshop on ALARA and specific instructions on the use of the on-line fax-on-demand service provided by BNL. Other topics included in this issue are: (1) A discussion of low-level discharges from Canadian nuclear plants, (2) Safety issues at French nuclear plants, (3) Acoustic emission as a means of leak detection, (4) Replacement of steam generators at Doel-3, Beaznau, and North Anna-1, (5) Remote handling equipment at Bruce, (6) EPRI's low level waste program, (7) Radiation protection during concrete repairs at Savannah River, (8) Reactor vessel stud removal/repair at Comanche Peak-1, (9) Rework of reactor coolant pump motors, (10) Restoration of service water at North Anna-1 and -2, (11) Steam generator tubing problems at Mihama-1, (12) Full system decontamination at Indian Point-2, (13) Chemical decontamination at Browns Ferry-2, and (14) Inspection methodolody in France and Japan

  2. Non-relativistic particles in a thermal bath

    Directory of Open Access Journals (Sweden)

    Vairo Antonio

    2014-04-01

    Full Text Available Heavy particles are a window to new physics and new phenomena. Since the late eighties they are treated by means of effective field theories that fully exploit the symmetries and power counting typical of non-relativistic systems. More recently these effective field theories have been extended to describe non-relativistic particles propagating in a medium. After introducing some general features common to any non-relativistic effective field theory, we discuss two specific examples: heavy Majorana neutrinos colliding in a hot plasma of Standard Model particles in the early universe and quarkonia produced in heavy-ion collisions dissociating in a quark-gluon plasma.

  3. Non-relativistic particles in a thermal bath

    CERN Document Server

    Vairo, Antonio

    2014-01-01

    Heavy particles are a window to new physics and new phenomena. Since the late eighties they are treated by means of effective field theories that fully exploit the symmetries and power counting typical of non-relativistic systems. More recently these effective field theories have been extended to describe non-relativistic particles propagating in a medium. After introducing some general features common to any non-relativistic effective field theory, we discuss two specific examples: heavy Majorana neutrinos colliding in a hot plasma of Standard Model particles in the early universe and quarkonia produced in heavy-ion collisions dissociating in a quark-gluon plasma.

  4. QED and relativistic corrections in superheavy elements

    CERN Document Server

    Indelicato, P J; Desclaux, J P; Santos, J P; Indelicato, Paul

    2007-01-01

    In this paper we review the different relativistic and QED contributions to energies, ionic radii, transition probabilities and Land\\'{e} $g$-factors in super-heavy elements, with the help of the MultiConfiguration Dirac-Fock method (MCDF). The effects of taking into account the Breit interaction to all orders by including it in the self-consistent field process are demonstrated. State of the art radiative corrections are included in the calculation and discussed. We also study the non-relativistic limit of MCDF calculation and find that the non-relativistic offset can be unexpectedly large.

  5. Event-by-event gluon multiplicity, energy density, and eccentricities in ultrarelativistic heavy-ion collisions

    Science.gov (United States)

    Schenke, Björn; Tribedy, Prithwish; Venugopalan, Raju

    2012-09-01

    The event-by-event multiplicity distribution, the energy densities and energy density weighted eccentricity moments ɛn (up to n=6) at early times in heavy-ion collisions at both the BNL Relativistic Heavy Ion Collider (RHIC) (s=200GeV) and the CERN Large Hardron Collider (LHC) (s=2.76TeV) are computed in the IP-Glasma model. This framework combines the impact parameter dependent saturation model (IP-Sat) for nucleon parton distributions (constrained by HERA deeply inelastic scattering data) with an event-by-event classical Yang-Mills description of early-time gluon fields in heavy-ion collisions. The model produces multiplicity distributions that are convolutions of negative binomial distributions without further assumptions or parameters. In the limit of large dense systems, the n-particle gluon distribution predicted by the Glasma-flux tube model is demonstrated to be nonperturbatively robust. In the general case, the effect of additional geometrical fluctuations is quantified. The eccentricity moments are compared to the MC-KLN model; a noteworthy feature is that fluctuation dominated odd moments are consistently larger than in the MC-KLN model.

  6. Proceedings of RIKEN BNL Research Center Workshop: Progress in High-pT Physics at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Bazilevsky, A.; Bland, L.; Vogelsang, W.

    2010-03-17

    This volume archives the presentations at the RIKEN BNL Research Center workshop 'Progress in High-PT Physics at RHIC', held at BNL in March 2010. Much has been learned from high-p{sub T} physics after 10 years of RHIC operations for heavy-ion collisions, polarized proton collisions and d+Au collisions. The workshop focused on recent progress in these areas by both theory and experiment. The first morning saw review talks on the theory of RHIC high-p{sub T} physics by G. Sterman and J. Soffer, and on the experimental results by M. Tannenbaum. One of the most exciting recent results from the RHIC spin program is the first observation of W bosons and their associated single-spin asymmetry. The new preliminary data were reported on the first day of our workshop, along with a theoretical perspective. There also were detailed discussions on the global analysis of polarized parton distributions, including the knowledge on gluon polarization and the impact of the W-data. The main topic of the second workshop day were single-transverse spin asymmetries and their analysis in terms of transverse-momentum dependent parton distributions. There is currently much interest in a future Drell-Yan program at RHIC, thanks to the exciting physics opportunities this would offer. This was addressed in some of the talks. There also were presentations on the latest results on transverse-spin physics from HERMES and BELLE. On the final day of the workshop, the focus shifted toward forward and small-x physics at RHIC, which has become a cornerstone of the whole RHIC program. Exciting new data were presented and discussed in terms of their possible implications for our understanding of strong color-field phenomena in QCD. In the afternoon, there were discussions of nuclear parton distributions and jet observables, among them fragmentation. The workshop was concluded with outlooks toward the near-term (LHC, JLab) and longer-term (EIC) future. The workshop has been a great success

  7. Relativistic electron- and proton-impact ionization of highly stripped heavy ions determined from projectile-electron loss in H2 and He

    International Nuclear Information System (INIS)

    We show that electron- and proton-impact ionization cross sections for highly stripped heavy ions can be deduced from the projectile-electron-loss cross sections determined by collisions with a H2 and a He target. We measure electron loss for 100- and 380-MeV/u Au52+, and 405-MeV/u U86+ in H2 and He targets, and extract the electron- and proton-impact ionization cross sections. Our results are compared with calculations and with channeling experiments

  8. The B->pi l nu and Bs->K l nu form factors and |Vub| from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

    CERN Document Server

    Flynn, J M; Kawanai, T; Lehner, C; Soni, A; Van de Water, R S; Witzel, O

    2015-01-01

    We calculate the form factors for B->pi l nu & Bs->K l nu decay in lattice QCD. We use the (2+1)-flavor RBC-UKQCD gauge field-ensembles generated with the domain-wall fermion and Iwasaki gauge actions. For the b quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation. We analyze data at 2 lattice spacings a~0.11, 0.086 fm with pion masses as light as M_pi~290 MeV. We extrapolate our numerical results to the physical light-quark masses and to the continuum and interpolate in the pion/kaon energy using SU(2) "hard-pion" chiral perturbation theory. We provide complete systematic error budgets for the vector & scalar form factors f+(q^2) & f0(q2) for B->pi l nu & Bs ->K l nu at 3 momenta that span the q^2 range accessible in our numerical simulations. Next we extrapolate these results to q^2 = 0 using a model-independent z-parameterization based on analyticity & unitarity. We present our final results for f+(q^2) & f0(q^2) as the z coefficients and matr...

  9. Relativistic Achilles

    CERN Document Server

    Leardini, Fabrice

    2013-01-01

    This manuscript presents a problem on special relativity theory (SRT) which embodies an apparent paradox relying on the concept of simultaneity. The problem is represented in the framework of Greek epic poetry and structured in a didactic way. Owing to the characteristic properties of Lorenz transformations, three events which are simultaneous in a given inertial reference system, occur at different times in the other two reference frames. In contrast to the famous twin paradox, in the present case there are three, not two, different inertial observers. This feature provides a better framework to expose some of the main characteristics of SRT, in particular, the concept of velocity and the relativistic rule of addition of velocities.

  10. 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)

  11. Applying Bayesian parameter estimation to relativistic heavy-ion collisions: Simultaneous characterization of the initial state and quark-gluon plasma medium

    Science.gov (United States)

    Bernhard, Jonah E.; Moreland, J. Scott; Bass, Steffen A.; Liu, Jia; Heinz, Ulrich

    2016-08-01

    We quantitatively estimate properties of the quark-gluon plasma created in ultrarelativistic heavy-ion collisions utilizing Bayesian statistics and a multiparameter model-to-data comparison. The study is performed using a recently developed parametric initial condition model, TRENTo, which interpolates among a general class of particle production schemes, and a modern hybrid model which couples viscous hydrodynamics to a hadronic cascade. We calibrate the model to multiplicity, transverse momentum, and flow data and report constraints on the parametrized initial conditions and the temperature-dependent transport coefficients of the quark-gluon plasma. We show that initial entropy deposition is consistent with a saturation-based picture, extract a relation between the minimum value and slope of the temperature-dependent specific shear viscosity, and find a clear signal for a nonzero bulk viscosity.

  12. Verification of Monte-Carlo transport codes FLUKA, GEANT4 and SHIELD for radiation protection purposes at relativistic heavy-ion accelerators

    International Nuclear Information System (INIS)

    The crucial problem for radiation shielding design at heavy-ion accelerator facilities with beam energies to several GeV/n is the source term problem. Experimental data on double differential neutron yields from thick target irradiated with high-energy uranium nuclei are lacking. At present, there are not many Monte-Carlo multipurpose codes that can work with primary high-energy uranium nuclei. These codes use different physical models for simulation of nucleus-nucleus reactions. Therefore, verification of the codes with available experimental data is very important for selection of the most reliable code for practical tasks. This paper presents comparisons of the FLUKA, GEANT4 and SHIELD codes simulations with the experimental data on neutron production at 1 GeV/n 238U beam interaction with thick Fe target

  13. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOLUME 70)

    Energy Technology Data Exchange (ETDEWEB)

    JACAK, B.; SHURYAK, E.; HALLMAN, T.; BASS, S.; DAVIDSON, R.

    2005-01-14

    The Relativistic Heavy Ion Collider (RHIC) was commissioned for heavy ion collisions and for polarized pp collisions in 2001. All principal components of the accelerator chain were operational by the 2003 RHIC run. Approximately 50 papers on RHIC experimental results have been published in refereed journals to date. This is a testament to the vast amount of exciting new information and the unprecedented analysis and publication rate from RHIC. A number of signals of creation of matter at extreme energy density, and of new physics in that matter, have been observed. The RHIC community has been heavily engaged in discussion about these signals, and about the appropriate level of proof for Quark Gluon Plasma discovery at the RHIC. In fact, such discussions were the subject of an earlier RBRC Workshop. One of the striking results from heavy ion collisions at RHIC is that the quark gluon plasma accessible appears to be strongly coupled. The properties of strongly coupled plasmas are of intense interest in the traditional Plasma Physics community, who have been developing tools to study such matter theoretically and experimentally. Despite the fact that one plasma interacts electromagnetically and the other through the strong interaction, there is tremendous commonality in the intellectual approach and even the theoretical and experimental tools. It is important to broaden the discussion of Quark Gluon Plasma discovery beyond possible signals of deconfinement to also encompass signals of plasma phenomena in heavy ion collisions. Thus it is imperative establish more direct contact among Nuclear, Plasma and Atomic physicists to share techniques and ideas. RHIC physicists will benefit from familiarity with typical plasma diagnostics and theoretical methods to study strongly coupled plasmas. Plasma and Atomic physicists may fmd new techniques parallel to the multi-particle correlations used in RHIC data analysis, and theoretical tools to study high energy density matter

  14. Data Model of the BNL Archive and Dissemination System

    Energy Technology Data Exchange (ETDEWEB)

    Heller, J; Osterer, L

    1977-02-01

    The Data Model, i.e., the information content of the data base as it is viewed by the users, of the BNL Archive and Dissemination System is presented. The syntax of the data model is stated in BNF form, and the semantic meaning is discussed. Examples of the use of the data model are given. 3 figs.

  15. BNL hypernuclear spectrometers and instrumentation present and future

    International Nuclear Information System (INIS)

    During the period 1981 to 1984 the BNL hypernuclear spectrometer system was upgraded resulting in an increase in kaon flux and an increase in solid angle and momentum acceptance. The modifications require drift chambers to be operated at rates up to 107 s-1. The performance of the spectrometer-drift chamber systems will be discussed

  16. Jet asymmetry and momentum imbalance from $2 \\to 2$ and $2 \\to 3$ partonic processes in relativistic heavy-ion collisions

    CERN Document Server

    Ayala, Alejandro; Jalilian-Marian, Jamal; Tejeda-Yeomans, Maria Elena

    2015-01-01

    We study momentum imbalance as a function of jet asymmetry in high-energy heavy-ion collisions. To implement parton production during the collision, we include all Leading Order (LO) $2\\to 2$ and $2\\to 3$ parton processes in pQCD. The produced partons lose energy within the quark gluon plasma and hadronize collinearly when they leave it. The energy and momentum deposited into the plasma is described using linear viscous hydrodynamics with a constant energy loss per unit length and a total energy loss given by a Gaussian probability centered around a mean value $\\bar{\\mathcal{E}}$ and a half-width $\\Delta{\\mathcal{E}}$. We argue that the shape of the asymmetry observed by the CERN-CMS Collaboration can indeed be attributed to parton energy loss in the medium and that a good description of data is achieved when one includes a slight enhancement coming from the contribution of $2\\to 3$ parton processes that modifies the asymmetry distribution of the dijet events. We compare our results to CMS data for the most c...

  17. Development of large area diamond detectors for time-of-flight measurements of relativistic heavy ions for the super-FRS

    Science.gov (United States)

    Schirru, F.; Nociforo, C.; Kiš, M.; Ciobanu, M.; Frühauf, J.; Kratz, A.; Kurz, N.; Szczepanczyk, B.; Träger, M.; Visinka, R.

    2016-06-01

    Time-of-flight (ToF) performances of large area diamond detectors based on polycrystalline samples of dimensions 20 mm  ×  20 mm and thickness of 0.3 mm are presented. The devices that feature segmented Cr/Au electrodes in a sandwich configuration were irradiated with a heavy ions 197Au beam of 1 GeV u‑1 showing, when mounted with a separation distance of 2 cm, a ToF resolution \\barσ of 37.5 ps averaged on 16 strip pairs. When ToF measurements were performed over a particle path of 30 m, a resolution σ of 45 ps was achieved. The detectors were mounted on high-vacuum compatible printed circuit boards (PCBs) with integrated processing electronics. This is the first time that ToF measurements have been performed using integrated electronics with such a large separation distance between the diamond detectors.

  18. THE BNL ASTD FIELD LAB - NEAR - REAL - TIME CHARACTERIZATION OF BNL STOCKPILED SOILS TO ACCELERATE COMPLETION OF THE EM CHEMICAL HOLES PROJECT

    International Nuclear Information System (INIS)

    As of October 2001, approximately 7,000 yd3 of stockpiled soil remained at Brookhaven National Laboratory (BNL) after the remediation of the BNL Chemical/Animal/Glass Pits disposal area. The soils were originally contaminated with radioactive materials and heavy metals, depending on what materials had been interred in the pits, and how the pits were excavated. During the 1997 removal action, the more hazardous/radioactive materials were segregated, along with, chemical liquids and solids, animal carcasses, intact gas cylinders, and a large quantity of metal and glass debris. Nearly all of these materials have been disposed of. In order to ensure that all debris was removed and to characterize the large quantity of heterogeneous soil, BNL initiated an extended sorting, segregation, and characterization project directed at the remaining soil stockpiles. The project was co-funded by the Department of Energy Environmental Management Office (DOE EM) through the BNL Environmental Restoration program and through the DOE EM Office of Science and Technology Accelerated Site Technology Deployment (ASTD) program. The focus was to remove any non-conforming items, and to assure that mercury and radioactive contaminant levels were within acceptable limits for disposal as low-level radioactive waste. Soils with mercury concentrations above allowable levels would be separated for disposal as mixed waste. Sorting and segregation were conducted simultaneously. Large stockpiles (ranging from 150 to 1,200 yd3) were subdivided into manageable 20 yd3 units after powered vibratory screening. The 1/2-inch screen removed almost all non-conforming items (plus some gravel). Non-conforming items were separated for further characterization. Soil that passed through the screen was also visually inspected before being moved to a 20 yd3 ''subpile.'' Eight samples from each subpile were collected after establishing a grid of four quadrants: north, east, south and west, and two layers: top and

  19. Theoretical study of the relativistic molecular rotational g-tensor

    Energy Technology Data Exchange (ETDEWEB)

    Aucar, I. Agustín, E-mail: agustin.aucar@conicet.gov.ar; Gomez, Sergio S., E-mail: ssgomez@exa.unne.edu.ar [Institute for Modeling and Technological Innovation, IMIT (CONICET-UNNE) and Faculty of Exact and Natural Sciences, Northeastern University of Argentina, Avenida Libertad 5400, W3404AAS Corrientes (Argentina); Giribet, Claudia G.; Ruiz de Azúa, Martín C. [Physics Department, Faculty of Exact and Natural Sciences, University of Buenos Aires and IFIBA CONICET, Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina)

    2014-11-21

    An original formulation of the relativistic molecular rotational g-tensor valid for heavy atom containing compounds is presented. In such formulation, the relevant terms of a molecular Hamiltonian for non-relativistic nuclei and relativistic electrons in the laboratory system are considered. Terms linear and bilinear in the nuclear rotation angular momentum and an external uniform magnetic field are considered within first and second order (relativistic) perturbation theory to obtain the rotational g-tensor. Relativistic effects are further analyzed by carrying out the linear response within the elimination of the small component expansion. Quantitative results for model systems HX (X=F, Cl, Br, I), XF (X=Cl, Br, I), and YH{sup +} (Y=Ne, Ar, Kr, Xe, Rn) are obtained both at the RPA and density functional theory levels of approximation. Relativistic effects are shown to be small for this molecular property. The relation between the rotational g-tensor and susceptibility tensor which is valid in the non-relativistic theory does not hold within the relativistic framework, and differences between both molecular parameters are analyzed for the model systems under study. It is found that the non-relativistic relation remains valid within 2% even for the heavy HI, IF, and XeH{sup +} systems. Only for the sixth-row Rn atom a significant deviation of this relation is found.

  20. Theoretical study of the relativistic molecular rotational g-tensor.

    Science.gov (United States)

    Aucar, I Agustín; Gomez, Sergio S; Giribet, Claudia G; Ruiz de Azúa, Martín C

    2014-11-21

    An original formulation of the relativistic molecular rotational g-tensor valid for heavy atom containing compounds is presented. In such formulation, the relevant terms of a molecular Hamiltonian for non-relativistic nuclei and relativistic electrons in the laboratory system are considered. Terms linear and bilinear in the nuclear rotation angular momentum and an external uniform magnetic field are considered within first and second order (relativistic) perturbation theory to obtain the rotational g-tensor. Relativistic effects are further analyzed by carrying out the linear response within the elimination of the small component expansion. Quantitative results for model systems HX (X=F, Cl, Br, I), XF (X=Cl, Br, I), and YH(+) (Y=Ne, Ar, Kr, Xe, Rn) are obtained both at the RPA and density functional theory levels of approximation. Relativistic effects are shown to be small for this molecular property. The relation between the rotational g-tensor and susceptibility tensor which is valid in the non-relativistic theory does not hold within the relativistic framework, and differences between both molecular parameters are analyzed for the model systems under study. It is found that the non-relativistic relation remains valid within 2% even for the heavy HI, IF, and XeH(+) systems. Only for the sixth-row Rn atom a significant deviation of this relation is found. PMID:25416870

  1. Search for (exotic) strange matter in the Star and Alice experiments with the ultra-relativistic heavy ion colliders RHIC and LHC; Recherche de matiere etrange (exotique) dans les experiences STAR et ALICE aupres des collisionneurs d'ions lourds ultra-relativistes RHIC et LHC

    Energy Technology Data Exchange (ETDEWEB)

    Vernet, R

    2006-02-15

    Ultra-relativistic heavy ion collisions offer the possibility to create conditions of temperature and density that could lead nuclear matter to a state of deconfined partons, the quark-gluon plasma. Strange baryon production is one of the essential observables to understand the mechanisms involved in the medium. Furthermore, theories predict a possible production of strange dibaryons, still hypothetical particles, from which one could draw important inferences in nuclear physics and astrophysics. The experiments STAR at RHIC, and, soon, ALICE at LHC, allow one to search for strange baryons and dibaryons. The STAR sensitivity to the metastable dibaryon H{sup 0} in the {lambda}p{pi}{sup -} decay mode was calculated thanks to a dedicated simulation. The search for the H{sup 0}, and for the {xi}{sup -}p resonance as well, was performed in the STAR Au+Au data at {radical}(s{sub NN}) = 62.4 and 200 GeV energies. Within the framework of the preparation of ALICE to the first Pb+Pb data, the detector ability to identify strange baryons {lambda}, {xi} and {omega}, was estimated via several simulations. So as to favour the reconstruction efficiency in a large range of transverse momentum while keeping a reasonable S/B ratio, the influence of the geometrical selections and the size of the reconstruction zone was emphasized. The ALICE sensitivities to the metastable strange dibaryons H{sup 0} and ({xi}{sup 0}p){sub b} and to the {lambda}{lambda} resonance were calculated as well. (author)

  2. Hadron Production in Heavy Ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, Hans Georg; Xu, Nu

    2009-05-19

    Heavy ion collisions are an ideal tool to explore the QCD phase diagram. The goal is to study the equation of state (EOS) and to search for possible in-medium modifications of hadrons. By varying the collision energy a variety of regimes with their specific physics interest can be studied. At energies of a few GeV per nucleon, the regime where experiments were performed first at the Berkeley Bevalac and later at the Schwer-Ionen-Synchrotron (SIS) at GSI in Darmstadt, we study the equation of state of dense nuclear matter and try to identify in-medium modifications of hadrons. Towards higher energies, the regime of the Alternating Gradient Synchrotron (AGS) at the Brookhaven National Laboratory (BNL), the Super-Proton Synchrotron (SPS) at CERN, and the Relativistic Heavy Ion Collider (RHIC) at BNL, we expect to produce a new state of matter, the Quark-Gluon Plasma (QGP). The physics goal is to identify the QGP and to study its properties. By varying the energy, different forms of matter are produced. At low energies we study dense nuclear matter, similar to the type of matter neutron stars are made of. As the energy is increased the main constituents of the matter will change. Baryon excitations will become more prevalent (resonance matter). Eventually we produce deconfined partonic matter that is thought to be in the core of neutron stars and that existed in the early universe. At low energies a great variety of collective effects is observed and a rather good understanding of the particle production has been achieved, especially that of the most abundantly produced pions and kaons. Many observations can be interpreted as time-ordered emission of various particle species. It is possible to determine, albeit model dependent, the equation of state of nuclear matter. We also have seen indications, that the kaon mass, especially the mass of the K{sup +}, might be modified by the medium created in heavy ion collisions. At AGS energies and above, emphasis shifts towards

  3. Relativistic diffusive transport

    OpenAIRE

    Haba, Z.

    2009-01-01

    We discuss transport equations resulting from relativistic diffusions in the proper time. We show that a solution of the transport equation can be obtained from the solution of the diffusion equation by means of an integration over the proper time. We study the stochastic processes solving the relativistic diffusion equation and the relativistic transport equation. We show that the relativistic transport equation for massive particles in the light cone coordinates and for massless particles i...

  4. Relativistic Theory of Superconductivity

    OpenAIRE

    Capelle, K.; Marques, M. A. L.; Gross, E. K. U.

    2001-01-01

    The relativistic generalization of the theory of superconductivity is reviewed with respect to its conceptual basis and first applications. The construction of relativistically covariant order parameters for superconductors is outlined and the generalization of the Dirac equation for the superconducting state is presented. A weakly relativistic expansion of this equation leads to the Pauli equation for superconductors, which describes the lowest-order relativistic corrections to the conventio...

  5. Relativistic Fluid Dynamics

    CERN Document Server

    Cattaneo, Carlo

    2011-01-01

    This title includes: Pham Mau Quam: Problemes mathematiques en hydrodynamique relativiste; A. Lichnerowicz: Ondes de choc, ondes infinitesimales et rayons en hydrodynamique et magnetohydrodynamique relativistes; A.H. Taub: Variational principles in general relativity; J. Ehlers: General relativistic kinetic theory of gases; K. Marathe: Abstract Minkowski spaces as fibre bundles; and, G. Boillat: Sur la propagation de la chaleur en relativite.

  6. BNL Citric Acid Technology: Pilot Scale Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    FRANCIS, A J; DODGE,; J, C; GILLOW, J B; FORRESTER, K E

    1999-09-24

    The objective of this project is to remove toxic metals such as lead and cadmium from incinerator ash using the Citric Acid Process developed at Brookhaven National Laboratory. In this process toxic metals in bottom ash from the incineration of municipal solid waste were first extracted with citric acid followed by biodegradation of the citric acid-metal extract by the bacterium Pseudomonas fluorescens for metals recovery. The ash contained the following metals: Al, As, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Se, Sr, Ti, and Zn. Optimization of the Citric Acid Process parameters which included citric acid molarity, contact time, the impact of mixing aggressiveness during extraction and pretreatment showed lead and cadmium removal from incinerator ash of >90%. Seeding the treated ash with P. fluorescens resulted in the removal of residual citric acid and biostabilization of any leachable lead, thus allowing it to pass EPA?s Toxicity Characteristic Leaching Procedure. Biodegradation of the citric acid extract removed >99% of the lead from the extract as well as other metals such as Al, Ca, Cu, Fe, Mg, Mn, Ti, and Zn. Speciation of the bioprecipitated lead by Extended X-ray Absorption Fine Structure at the National Synchrotron Light Source showed that the lead is predominantly associated with the phosphate and carboxyl functional groups in a stable form. Citric acid was completely recovered (>99%) from the extract by sulfide precipitation technique and the extraction efficiency of recovered citric acid is similar to that of the fresh citric acid. Recycling of the citric acid should result in considerable savings in the overall treatment cost. We have shown the potential application of this technology to remove and recover the metal contaminants from incinerator ash as well as from other heavy metal bearing wastes (i.e., electric arc furnace dust from steel industry) or soils. Information developed from this project is being applied to demonstrate the remediation of

  7. Bremsstrahlung from relativistic heavy ions in matter

    DEFF Research Database (Denmark)

    Sørensen, Allan Hvidkjær

    2010-01-01

     MeV for a lead ion (γ≡E/Mc2 is the Lorentz factor of the projectile of energy E and mass M). The maximum exceeds the bremsstrahlung from a hypothetical structureless, pointlike particle of the same charge and mass as the incoming nucleus, but rapid depletion follows on the high-energy side of the peak...

  8. Measurement of high-pT single electrons from heavy-flavor decays in p + p collisions at square root of s = 200 GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; 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; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bickley, A A; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Campbell, 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; 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; 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; Esumi, S; Eyser, K O; Fields, D E; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Franz, A; Frantz, J; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Garishvili, I; 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; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hamagaki, H; Han, R; Harada, H; Hartouni, E P; Haruna, K; Haslum, E; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; He, X; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; 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; Kano, H; Kawall, D; Kazantsev, A V; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, E; 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; 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; Lee, D M; Lee, M K; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Liska, T; Litvinenko, A; Liu, M X; Li, X; 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; McCumber, M; McGaughey, P L; Miake, Y; Mikes, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, M; Mitchell, J T; Mitrovski, M; Morreale, A; Morrison, D P; 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; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Okada, H; Okada, K; Oka, M; Omiwade, O O; Oskarsson, A; 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; 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; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakata, H; Samsonov, V; Sato, S; Sawada, S; Seele, J; Seidl, R; Semenov, V; Seto, R; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Slunecka, 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; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; 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; 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; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y; 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

    2006-12-22

    The momentum distribution of electrons from decays of heavy flavor (charm and bottom) for midrapidity absolute value of y < 0.35 in p + p collisions at square root of s = 200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.3 < pT < 9 GeV/c. Two independent methods have been used to determine the heavy-flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.71+/-0.02stat+/-0.18sys for 0.3 < pT < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma cc = 567+/-57stat+/-193sys microb. PMID:17280343

  9. Relativistic Remnants of Non-Relativistic Electrons

    CERN Document Server

    Kashiwa, Taro

    2015-01-01

    Electrons obeying the Dirac equation are investigated under the non-relativistic $c \\mapsto \\infty$ limit. General solutions are given by derivatives of the relativistic invariant functions whose forms are different in the time- and the space-like region, yielding the delta function of $(ct)^2 - x^2$. This light-cone singularity does survive to show that the charge and the current density of electrons travel with the speed of light in spite of their massiveness.

  10. Relativistic Remnants of Non-Relativistic Electrons

    OpenAIRE

    Kashiwa, Taro; Yamaguchi, Taisuke

    2014-01-01

    Electrons obeying the Dirac equation are investigated under the non-relativistic $c \\mapsto \\infty$ limit. General solutions are given by derivatives of the relativistic invariant functions whose forms are different in the time- and the space-like region, yielding the delta function of $(ct)^2 - x^2$. This light-cone singularity does survive to show that the charge and the current density of electrons travel with the speed of light in spite of their massiveness.

  11. Relativistic Spin Operators

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng-Fei; RUAN Tu-Nan

    2001-01-01

    A systematic theory on the appropriate spin operators for the relativistic states is developed. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativistic one, which is called in this paper as moving spin. Further the concept of moving spin is discussed in the quantum field theory. A new is constructed. It is shown that, in virtue of the two operators, problems in quantum field concerned spin can be neatly settled.

  12. Relativistic Linear Restoring Force

    Science.gov (United States)

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  13. Relativistic Guiding Center Equations

    Energy Technology Data Exchange (ETDEWEB)

    White, R. B. [PPPL; Gobbin, M. [Euratom-ENEA Association

    2014-10-01

    In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.

  14. Results from the experiment E895 at the BNL AGS

    CERN Document Server

    Rai, G; Alexander, J; Anderson, M; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D A; Chance, J L; Chung, P; Cole, B; Crowe, K; Das, A; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A S; Hjort, E L; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J; Klay, J; Krofcheck, D; Lacey, R; Lisa, M A; Liu, H; Liu, Y M; McGrath, R; Milosevich, Z; Odyniec, Grazyna Janina; Olson, D L; Panitkin, S Y; Pinkenburg, C H; Porile, N T; Ritter, H G; Romero, J L; Scharenberg, R P; Schröder, L S; Srivastava, B K; Stone, N T B; Symons, T J M; Wang, S; Wells, R; Whitfield, J; Wienold, T; Witt, R; Wood, L; Yang, X; Zhang, W; Zhang, Y

    1999-01-01

    We present some of the latest results from the E895 experiment conducted at the BNL AGS accelerator. Au+Au collisions were recorded by the EOS Time Projection Chamber (TPC) at beam energies of 2, 4, 6, and 8 A GeV. The TPC detector permitted the reconstruction of individual collision events with almost 4 pi acceptance and good particle identification. This capability allowed E895 to study global observables and two particle correlations with respect to symmetries of the event. Flow excitation functions are examined and discussed in the context of the Nuclear Equation of State.

  15. Studies of new inorganic species using relativistic quantum chemistry

    OpenAIRE

    Patzschke, Michael

    2006-01-01

    In the present work the methods of relativistic quantum chemistry have been applied to a number of small systems containing heavy elements, for which relativistic effects are important. First, a thorough introduction of the methods used is presented. This includes some of the general methods of computational chemistry and a special section dealing with how to include the effects of relativity in quantum chemical calculations. Second, after this introduction the results obtained are prese...

  16. Calculation of the relativistic Bloch correction to stopping power

    Science.gov (United States)

    Ahlen, S. P.

    1982-01-01

    Bloch's technique of joining the nonrelativistic Bethe and Bohr stopping-power expressions by taking into account wave-packet effects for close collisions is extended to the relativistic case. It is found that Bloch's nonrelativistic correction term must be modified and that charge asymmetric terms appear. Excellent agreement is observed by comparing the results of these calculations to recent data on the stopping power of relativistic heavy ions.

  17. Evolution of direct mechanisms with incident energy from the Coulomb-barrier to relativistic energies. - Two-center effects in nucleon transfer between nuclei. - Signatures of nucleon promotion in heavy ion reactions at barrier energies

    International Nuclear Information System (INIS)

    This report contains a review article considering the evolution of direct mechanisms with incident energy in heavy ion reactions and two theoretical articles concerning two-center effects in transfer reactions between heavy ions and the nucleon promotion in heavy ion reactions. See hints under the relevant topics. (HSI)

  18. RELATIVISTIC TRANSPORT-THEORY

    NARCIS (Netherlands)

    MALFLIET, R

    1993-01-01

    We discuss the present status of relativistic transport theory. Special emphasis is put on problems of topical interest: hadronic features, thermodynamical consistent approximations and spectral properties.

  19. L-shell ionization by relativistic electrons

    International Nuclear Information System (INIS)

    Measurements of the relative x-ray production cross-sections Lsub(α)/Lsub(l), Lsub(β)/Lsub(α) and Lsub (γ)/Lsub(α) by relativistic electrons for the heavy elements Gd, Tm, Ta, Au, Pb, Bi and Th have been carried out. The ratios Lsub(β)/Lsub(α) and Lsub(α)/Lsub (l), are compared with previous experimental and theoretical work

  20. Using MUSIC to study relativistic nuclear collisions

    International Nuclear Information System (INIS)

    A large Multiple Sampling Ionization Chamber (MUSIC) has been developed as a part of the Heavy Ion Spectrometer System (HISS). This facility is being used for the study of relativistic nuclear collisions at the Bevalac of Lawrence Berkeley Laboratory. Preliminary data from MUSIC indicate that a charge resolution of one unit should be achieved from Z approximately equal to 7 to Z approximately equal to 100. (author)

  1. $\\Lambda$ polarization in peripheral collisions at moderate relativistic energies

    CERN Document Server

    Xie, Y L; Stöcker, H; Wang, D J; Csernai, L P

    2016-01-01

    The polarization of $\\Lambda$ hyperons from relativistic flow vorticity is studied in peripheral heavy ion reactions at FAIR and NICA energies, just above the threshold of the transition to the Quark-Gluon Plasma. Previous calculations at higher energies with larger initial angular momentum, predicted significant $\\Lambda$ polarization based on the classical vorticity term in the polarization, while relativistic modifications decreased the polarization and changed its structure in the momentum space. At the lower energies studied here, we see the same effect namely that the relativistic modifications decrease the polarization arising from the initial shear flow vorticity.

  2. DOE/NORA/BNL oil heat research agenda development

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.J. [Brookhaven National Lab., Upton, NY (United States); Batey, J. [Energy Research Center, Easton, CT (United States)

    1996-07-01

    The National Oilheat Research Alliance (NORA) has been formed and is currently working to establish a Congressionally approved oilheat check-off program to provide funding for research, education, training, safety, and marketing to benefit the US oilheat industry. NORA will be presenting this program to the Congress for its consideration and approval in the coming year. It will follow the same path as the National Propane Gas Association which is currently working on obtaining Congressional approval of a propane check off program that has already attracted over 120 cosponsors in the House of representatives. An effort to define the basis of a joint US Department of Energy (DOE) and Oilheat industry (marketers) program for future oilheat equipment research and development will be conducted during FY-1996. At the request of NORA representatives BNL will coordinate the development of a research agenda addressing three categories of activities, research appropriate for DOE support only, research appropriate for NORA support only, and research appropriate for co-funding by both organizations. This will also serve to update a prior oil-fueled research plan developed for DOE ten years ago which has been the road map for DOE`s very successful Oil Heat R&D program at BNL.

  3. Heavy ions at the LHC: Physics perspectives and experimental program

    Indian Academy of Sciences (India)

    J Schukraft

    2001-08-01

    Ultrarelativistic heavy ion physics is entering the new era of collider experiments with the start-up of RHIC at BNL and construction for detectors at LHC well under way. At this crossroads, the article will give a summary of the experimental program and our current view of heavy ion physics at the LHC, concentrating in particular on physics topics that are different or unique compared to current facilities.

  4. Relativistic quantum mechanics; Mecanique quantique relativiste

    Energy Technology Data Exchange (ETDEWEB)

    Ollitrault, J.Y. [CEA Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Universite Pierre et Marie Curie, 75 - Paris (France)

    1998-12-01

    These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.) 2 refs.

  5. Relativistic Quark Physics

    OpenAIRE

    Rafelski, Johann

    1998-01-01

    We present a brief survey of the development of nuclear physics towards relativistic quark physics. This is followed by a thorough discussion of the quest for the observation of the dissolution of nuclear matter into the deconfined quark matter (QGP) in relativistic nuclear collisions. Use of strange particle signatures in search for QGP is emphasized.

  6. Towards relativistic quantum geometry

    Directory of Open Access Journals (Sweden)

    Luis Santiago Ridao

    2015-12-01

    Full Text Available We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.

  7. eRHIC Design Study: An Electron-Ion Collider at BNL

    CERN Document Server

    Aschenauer, E C; Bazilevsky, A; Boyle, K; Belomestnykh, S; Ben-Zvi, I; Brooks, S; Brutus, C; Burton, T; Fazio, S; Fedotov, A; Gassner, D; Hao, Y; Jing, Y; Kayran, D; Kiselev, A; Lamont, M A C; Lee, J -H; Litvinenko, V N; Liu, C; Ludlam, T; Mahler, G; McIntyre, G; Meng, W; Meot, F; Miller, T; Minty, M; Parker, B; Pinayev, I; Ptitsyn, V; Roser, T; Stratmann, M; Sichtermann, E; Skaritka, J; Tchoubar, O; Thieberger, P; Toll, T; Trbojevic, D; Tsoupas, N; Tuozzolo, J; Ullrich, T; Wang, E; Wang, G; Wu, Q; Xu, W; Zheng, L

    2014-01-01

    This document presents BNL's plan for an electron-ion collider, eRHIC, a major new research tool that builds on the existing RHIC facility to advance the long-term vision for Nuclear Physics to discover and understand the emergent phenomena of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction that binds the atomic nucleus. We describe the scientific requirements for such a facility, following up on the community wide 2012 white paper, "Electron-Ion Collider: the Next QCD Frontier", and present a design concept that incorporates new, innovative accelerator techniques to provide a cost-effective upgrade of RHIC with polarized electron beams colliding with the full array of RHIC hadron beams. The new facility will deliver electron-nucleon luminosity of $\\sim10^{33} cm^{-2}sec^{-1}$ for collisions of 15.9 GeV polarized electrons on either 250 GeV polarized protons or 100 GeV/u heavy ion beams. The facility will also be capable of providing an electron beam energy of 21.2 GeV, at reduc...

  8. EVENT DRIVEN AUTOMATIC STATE MODIFICATION OF BNL'S BOOSTER FOR NASA SPACE RADIATION LABORATORY SOLAR PARTICLE SIMULATOR.

    Energy Technology Data Exchange (ETDEWEB)

    BROWN, D.; BINELLO, S.; HARVEY, M.; MORRIS, J.; RUSEK, A.; TSOUPAS, N.

    2005-05-16

    The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. NASA is interested in reproducing the energy spectrum from a solar flare in the space environment for a single ion species. To do this we have built and tested a set of software tools which allow the state of the Booster and the NSRL beam line to be changed automatically. In this report we will describe the system and present results of beam tests.

  9. 3-D Relativistic MHD Simulations

    Science.gov (United States)

    Nishikawa, K.-I.; Frank, J.; Koide, S.; Sakai, J.-I.; Christodoulou, D. M.; Sol, H.; Mutel, R. L.

    1998-12-01

    We present 3-D numerical simulations of moderately hot, supersonic jets propagating initially along or obliquely to the field lines of a denser magnetized background medium with Lorentz factors of W = 4.56 and evolving in a four-dimensional spacetime. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently in the simulations. This effect is analogous to pushing Japanese ``noren'' or vertical Venetian blinds out of the way while the slats are allowed to bend in 3-D space rather than as a 2-D slab structure.

  10. Proceedings of RIKEN BNL Research Center workwhop on RHIC spin

    Energy Technology Data Exchange (ETDEWEB)

    SOFFER,J.

    1999-10-06

    This RHIC Spin Workshop is the 1999 annual meeting of the RHIC Spin Collaboration, and the second to be hosted at Brookhaven and sponsored by the RIKEN BNL Research Center. The previous meetings were at Brookhaven (1998), Marseille (1996), MIT in 1995, Argonne 1994, Tucson in 1991, and the Polarized Collider Workshop at Penn State in 1990. As noted last year, the Center provides a home for combined work on spin by theorists, experimenters, and accelerator physicists. This proceedings, as last year, is a compilation of 1 page summaries and 5 selected transparencies for each speaker. It is designed to be available soon after the workshop is completed. Speakers are welcome to include web or other references for additional material. The RHIC spin program and RHIC are rapidly becoming reality. RHIC has completed its first commissioning run, as described here by Steve Peggs. The first Siberian Snake for spin has been completed and is being installed in RHIC. A new polarized source from KEK and Triumf with over 1 milliampere of polarized H{sup minus} is being installed, described by Anatoli Zelenski. They have had a successful test of a new polarimeter for RHIC, described by Kazu Kurita and Haixin Huang. Spin commissioning is expected next spring (2000), and the first physics run for spin is anticipated for spring 2001. The purpose of the workshop is to get everyone together about once per year and discuss goals of the spin program, progress, problems, and new ideas. They also have many separate regular forums on spin. There are spin discussion sessions every Tuesday, now organized by Naohito Saito and Werner Vogelsang. The spin discussion schedule and copies of presentations are posted on http://riksg01.rhic.bnl.gov/rsc. Speakers and other spinners are encouraged to come to BNL and to lead a discussion on your favorite idea. They also have regular polarimeter and snake meetings on alternate Thursdays, led by Bill McGahern, the lead engineer for the accelerator spin

  11. Beam Loss Estimates and Control for the BNL Neutrino Facility

    CERN Document Server

    Weng, Wu-Tsung; Raparia, Deepak; Tsoupas, Nicholaos; Wei, Jie; Yung Lee, Yong; Zhang, S Y

    2005-01-01

    BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW for a very long baseline neutrino oscillation experiment. This increase in beam power is mainly due to the faster repetition rate of the AGS by a new 1.5 GeV superconductiong linac as injector, replacing the existing booster. The requirement for low beam loss is very important both to protect the beam component, and to make the hands-on maintenance possible. In this report, the design considerations for achieving high intensity and low loss will be presented. We start by specifying the beam loss limit at every physical process followed by the proper design and parameters for realising the required goals. The process considered in this paper include the emittance growth in the linac, the H-

  12. Field testing the prototype BNL fan-atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    BNL has developed a new oil burner design referred to as the Fan Atomized burner System. The primary objective of the field study was to evaluate and demonstrate the reliable operation of the Fan Atomized Burner. The secondary objective was to establish and validate the ability of a low firing rate burner (0.3-0.4 gph) to fully satisfy the heating and domestic hot water load demands of an average household in a climate zone with over 5,000 heating-degree-days. The field activity was also used to evaluate the practicality of side-wall venting with the Fan Atomized Burner with a low stack temperature (300F) and illustrate the potential for very high efficiency with an integrated heating system approach based on the Fan Atomized Burner.

  13. PHYSICS OF THE 1 TERAFLOP RIKEN-BNL-COLUMBIA QCD PROJECT.

    Energy Technology Data Exchange (ETDEWEB)

    MAWHINNEY,R.

    1998-10-16

    A workshop was held at the RIKEN-BNL Research Center on the afternoon of October 16, i 998, as part of the first anniversary ceremony for the center. Titled ''Workshop on Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD Project'', this meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. In addition, Akira Ukawa, a leader of the CP-PACS project at the University of Tsukuba in Japan, attended and gave a talk on the Aoki phase. There were also others in attendance who were interested in more general properties of the QCDSP computer. The QCDSP computer and lattice QCD had been presented during the morning ceremony by Shigemi Ohta of KEK and the RIKEN-BNL Research Center. This was followed by a tour of the QCDSP machine room and a formal unveiling of the computer to the attendees of the anniversary ceremony and the press. The rapid completion of construction of the QCDSP computer was made possible through many factors: (1) the existence of a complete design and working hardware at Columbia when the RIKEN-BNL center was being set up, (2) strong support for the project from RIKEN and the center and (3) aggressive involvement of members of the Computing and Communications Division at BNL. With this powerful new resource, the members of the RIKEN-BNL-Columbia, QCD project are looking forward to advances in our understanding of QCD.

  14. PHYSICS OF THE 1 TERAFLOP RIKEN-BNL-COLUMBIA QCD PROJECT.

    Energy Technology Data Exchange (ETDEWEB)

    MAWHINNEY,R.

    1998-10-16

    A workshop was held at the RIKEN-BNL Research Center on the afternoon of October 16, 1998, as part of the first anniversary ceremony for the center. Titled ''Workshop on Physics of the 1 Teraflop RIKEN-BNL-Columbia QCD Project'', this meeting brought together the physicists from RIKEN-BNL, BNL and Columbia who are using the QCDSP (Quantum Chromodynamics on Digital Signal Processors) computer at the RIKEN-BNL Research Center for studies of QCD. In addition, Akira Ukawa, a leader of the CP-PACS project at the University of Tsukuba in Japan, attended and gave a talk on the Aoki phase. There were also others in attendance who were interested in more general properties of the QCDSP computer. The QCDSP computer and lattice QCD had been presented during the morning ceremony by Shigemi Ohta of KEK and the RIKEN-BNL Research Center. This was followed by a tour of the QCDSP machine room and a formal unveiling of the computer to the attendees of the anniversary ceremony and the press. The rapid completion of construction of the QCDSP computer was made possible through many factors: (1) the existence of a complete design and working hardware at Columbia when the RIKEN-BNL center was being set up, (2) strong support for the project from RIKEN and the center and (3) aggressive involvement of members of the Computing and Communications Division at BNL. With this powerful new resource, the members of the RIKEN-BNL-Columbia, QCD project are looking forward to advances in our understanding of QCD.

  15. 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.)

  16. Relativistic Hall Effect

    CERN Document Server

    Bliokh, Konstantin Y

    2011-01-01

    We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the correct Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices, mechanical flywheel, and discuss various fundamental aspects of the phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales: from elementary spinning particles, through classical light, to rotating black-holes.

  17. Relativistic spherical plasma waves

    Science.gov (United States)

    Bulanov, S. S.; Maksimchuk, A.; Schroeder, C. B.; Zhidkov, A. G.; Esarey, E.; Leemans, W. P.

    2012-02-01

    Tightly focused laser pulses that diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we study theoretically and numerically relativistic spherical wake waves and their properties, including wave breaking.

  18. 7th high energy heavy ion study

    International Nuclear Information System (INIS)

    These proceedings contain the articles presented at the named conference. They deal with relativistic heavy ion reactions, the expansion and freeze-out of nuclear matter, anomalon experiments, and multifragmentation and particle correlations in heavy ion reactions. See hints under the relevant topics. (HSI)

  19. Renormalization of NN Interaction with Relativistic Chiral Two Pion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Higa, R; Valderrama, M Pavon; Arriola, E Ruiz

    2007-06-14

    The renormalization of the NN interaction with the Chiral Two Pion Exchange Potential computed using relativistic baryon chiral perturbation theory is considered. The short distance singularity reduces the number of counter-terms to about a half as those in the heavy-baryon expansion. Phase shifts and deuteron properties are evaluated and a general overall agreement is observed.

  20. BNL workshop on rare K decays and CP violation, August 25-27, 1988

    International Nuclear Information System (INIS)

    This report contains viewgraphs on the following topics: rare and forbidden K decays; CP violation in the K system; the status of current experiments at BNL, CERN, FNAL, and KEK; and future experiments and facilities

  1. BNL workshop on rare K decays and CP violation, August 25-27, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1988-10-01

    This report contains viewgraphs on the following topics: rare and forbidden K decays; CP violation in the K system; the status of current experiments at BNL, CERN, FNAL, and KEK; and future experiments and facilities.

  2. Relativistic internally contracted multireference electron correlation methods

    CERN Document Server

    Shiozaki, Toru

    2015-01-01

    We report internally contracted relativistic multireference configuration interaction (ic-MRCI), complete active space second-order perturbation (CASPT2), and strongly contracted n-electron valence state perturbation theory (NEVPT2) on the basis of the four-component Dirac Hamiltonian, enabling accurate simulations of relativistic, quasi-degenerate electronic structure of molecules containing transition-metal and heavy elements. Our derivation and implementation of ic-MRCI and CASPT2 are based on an automatic code generator that translates second-quantized ans\\"atze to tensor-based equations, and to efficient computer code. NEVPT2 is derived and implemented manually. The rovibrational transition energies and absorption spectra of HI and TlH are presented to demonstrate the accuracy of these methods.

  3. Strong decays of vector mesons to pseudoscalar mesons in the relativistic quark model

    Directory of Open Access Journals (Sweden)

    D. Ebert

    2015-05-01

    Full Text Available Strong decays of vector (S13 mesons to the pair of pseudoscalar (S01 mesons are considered in the framework of the microscopic decay mechanism and the relativistic quark model based on the quasipotential approach. The quark–antiquark potential, which was previously used for the successful description of meson spectroscopy and electroweak decays, is employed as the source of the qq¯ pair creation. The relativistic structure of the decay matrix element, relativistic contributions and boosts of the meson wave functions are comprehensively taken into account. The calculated rates of strong decays of light, heavy-light mesons and heavy quarkonia agree well with available experimental data.

  4. Strong decays of vector mesons to pseudoscalar mesons in the relativistic quark model

    CERN Document Server

    Ebert, D; Galkin, V O

    2014-01-01

    Strong decays of vector ($^3S_1$) mesons to the pair of pseudoscalar ($^1S_0$) mesons are considered in the framework of the microscopic decay mechanism and the relativistic quark model based on the quasipotential approach. The quark-antiquark potential, which was previously used for the successful description of meson spectroscopy and electroweak decays, is employed as the source of the $q\\bar q$ pair creation. The relativistic structure of the decay matrix element, relativistic contributions and boosts of the meson wave functions are comprehensively taken into account. The calculated rates of strong decays of light, heavy-light mesons and heavy quarkonia agree well with available experimental data.

  5. Matching heavy-light currents with NRQCD and HISQ quarks

    OpenAIRE

    Monahan, Christopher; Davies, Christine; Horgan, Ron; Lepage, G. Peter; Na, Heechang; Shigemitsu, Junko

    2012-01-01

    We calculate the one loop renormalisation parameters for the heavy-light axial-vector and vector currents using lattice perturbation theory. We use NonRelativistic QCD (NRQCD) heavy quarks and the Highly Improved Staggered Quark (HISQ) action for the light quarks. We present results for heavy-light currents with massless HISQ quarks and briefly discuss the extension to heavy-heavy currents with massive HISQ quarks.

  6. Centrality and energy dependence of charged-particle multiplicities in heavy ion collisions in the context of elementary reactions

    Science.gov (United States)

    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.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, 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.; Michałowski, 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.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2006-08-01

    The PHOBOS experiment at the BNL Relativistic Heavy Ion Collider has measured the total multiplicity of primary charged particles as a function of collision centrality in Au+Au collisions at sNN= 19.6, 130, and 200 GeV. An approximate independence of / on the number of participating nucleons is observed, reminiscent of “wounded nucleon” scaling (Nch∝Npart) observed in proton-nucleus collisions. Unlike p+A, the constant of proportionality does not seem to be set by the pp/p¯p data at the same energy. Rather, there seems to be a surprising correspondence with the total multiplicity measured in e+e- annihilations, as well as the rapidity shape measured over a large range. The energy dependence of the integrated multiplicity per participant pair shows that e+e- and A+A data agree over a large range of center-of-mass energies (s>20 GeV), and pp/p¯p data can be brought to agree approximately with the e+e- data by correcting for the typical energy taken away by leading particles. This is suggestive of a mechanism for soft particle production that depends mainly on the amount of available energy. It is conjectured that the dominant distinction between A+A and p+p collisions is the multiple collisions per participant, which appears to be sufficient to substantially reduce the energy taken away by leading particles.

  7. HARD PARTON PHYSICS IN HIGH ENERGY NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 17

    Energy Technology Data Exchange (ETDEWEB)

    CARROLL,J.

    1999-09-10

    The RIKEN-BNL center workshop on ''Hard parton physics in high energy nuclear collisions'' was held at BNL from March 1st-5th! 1999. The focus of the workshop was on hard probes of nucleus-nucleus collisions that will be measured at RHIC with the PHENIX and STAR detectors. There were about 45 speakers and over 70 registered participants at the workshop, with roughly a quarter of the speakers from overseas. About 60% of the talks were theory talks. A nice overview of theory for RHIC was provided by George Sterman. The theoretical talks were on a wide range of topics in QCD which can be classified under the following: (a) energy loss and the Landau-Pomeranchuk-Migdal effect; (b) minijet production and equilibration; (c) small x physics and initial conditions; (d) nuclear parton distributions and shadowing; (e) spin physics; (f) photon, di-lepton, and charm production; and (g) hadronization, and simulations of high pt physics in event generators. Several of the experimental talks discussed the capabilities of the PHENIX and STAR detectors at RHIC in measuring high pt particles in heavy ion collisions. In general, these talks were included in the relevant theory sessions. A session was set aside to discuss the spin program at RHIC with polarized proton beams. In addition, there were speakers from 08, HERA, the fixed target experiments at Fermilab, and the CERN fixed target Pb+Pb program, who provided additional perspective on a range of issues of relevance to RHIC; from jets at the Tevatron, to saturation of parton distributions at HERA, and recent puzzling data on direct photon production in fixed target experiments, among others.

  8. Theory of heavy ion collisions. Annual progress report

    International Nuclear Information System (INIS)

    It is demonstrated clearly that macroscopic models account for many of the observed features of heavy ion collisions. During this phase of the program major steps have been taken toward a better understanding of fusion excitation function, strongly damped collisions, the emission of nucleons at intermediate energies, heavy ion collisions and pions in relativistic heavy ion collisions

  9. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP (VOLUME 55) COLLECTIVE FLOW AND QGP PROPERTIES.

    Energy Technology Data Exchange (ETDEWEB)

    BASS,S.ESUMI,S.HEINZ,U.KOLB,P.SHURYAK,E.XU,N.

    2003-11-17

    The first three years of RHIC physics, with Au/Au collisions induced at 65, 130 and 200 GeV per nucleon pair, produced dramatic results, particularly with respect to collective observables such as transverse flow and anisotropies in transverse momentum spectra. It has become clear that the data show very strong rescattering at very early times of the reaction, strong enough in fact to be described by the hydrodynamic limit. Therefore, with today's experiments, we are able to investigate the equation of state of hot quark gluon matter, discuss its thermodynamic properties and relate them to experimental observables. At this workshop we came together to discuss our latest efforts both in the theoretical description of heavy ion collisions as well as most recent experimental results that ultimately allow us to extract information on the properties of RHIC matter. About 50 participants registered for the workshop, but many more dropped in from the offices at BNL. The workshop lasted for three days, of which each day was assigned a special topic on which the talks focused. On the first day we dealt with the more general question what the strong collective phenomena observed in RHIC collisions tell us about the properties and the dynamics of RHIC matter. The second day covered all different aspects of momentum anisotropies, and interesting new experimental results were presented for the first time. On the third day, we focused on the late fireball dynamics and the breakdown of the assumption of thermalization. New experimental observables were discussed, which will deliver more information of how the expanding fireball breaks up, once the frequent interaction ceases.

  10. Relativistic Multiple Scattering Theory and the Relativistic Impulse Approximation

    OpenAIRE

    Maung, Khin Maung; Norbury, John W.; Coleman, Trina

    2007-01-01

    It is shown that a relativistic multiple scattering theory for hadron-nucleus scattering can be consistently formulated in four-dimensions in the context of meson exchange. We give a multiple scattering series for the optical potential and discuss the differences between the relativistic and non-relativistic versions. We develop the relativistic multiple scattering series by separating out the one boson exchange term from the rest of the Feynman series. However this particular separation is n...

  11. The BNL Accelerator Test Facility and experimental program

    International Nuclear Information System (INIS)

    The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high power laser pulses synchronized to the electron beam, suitable for studies of new methods of high gradient acceleration and state of the art free electron lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 to 100 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps Nd:YAG laser and a 100 mJ, 10 ps CO2 laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various acceleration schemes, Free-Electron Laser experiments and a program on the development of high brightness electron beams. The AFT's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the High power laser will begin operation this year. 28 refs., 4 figs

  12. First Results from the DUV-FEL Upgrade at BNL

    CERN Document Server

    Wang, Xijie; Murphy, James; Pinayev, Igor; Rakowsky, George; Rose, James; Shaftan, Timur; Sheehy, Brian; Skaritka, John; Wu, Zilu; Yu Li Hua

    2005-01-01

    The DUV-FEL at BNL is the world’s only facility dedicated to laser-seeded FEL R&D and its applications. Tremendous progress was made in both HGHG FEL and its applications in the last couple years.*,** In response to the requests of many users to study chemical science at the facility, the DUV-FEL linac was upgraded from 200 to 300 MeV to enable the HGHG FEL to produce 100 uJ pulses of 100 nm light. This will establish the DUV FEL as a premier user facility for ultraviolet radiation and enable state-of-the-art gas phase photochemistry research. The upgraded facility will also make possible key R&D experiments such as higher harmonic HGHG (n>5) that would lay the groundwork for future X-ray FEL based on HGHG. The upgraded HGHG FEL will operate at the 4th harmonic with the seed laser at either 800 nm or 400nm. The increase of the electron beam energy will be accomplished by installing a 5th linac cavity and two 45 MW klystrons. New HGHG modulator and dispersion sections vacuum chambers w...

  13. The BNL fan-atomized burner system prototype

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    Brookhaven National Laboratory (BNL) has a continuing interest in the development of advanced oil burners which can provide new capabilities not currently available with pressure atomized, retention head burners. Specifically program goals include: the ability to operate at firing rates as low as 0.25 gph; the ability to operate with very low excess air levels for high steady state efficiency and to minimize formation of sulfuric acid and iron sulfate fouling; low emissions of smoke, CO, and NO{sub x} even at very low excess air levels; and the potential for modulation - either staged firing or continuous modulation. In addition any such advanced burner must have production costs which would be sufficiently attractive to allow commercialization. The primary motivation for all work sponsored by the US DOE is, of course, improved efficiency. With existing boiler and furnace models this can be achieved through down-firing and low excess air operation. Also, with low excess air operation fouling and efficiency degradation due to iron-sulfate scale formation are reduced.

  14. BWR stability analysis with the BNL Engineering Plant Analyzer

    International Nuclear Information System (INIS)

    March 9, 1989 instability at the LaSalle-2 Power Plant and more than ninety related BWR transients have been simulated on the BNL Engineering Plant Analyzer (EPA). Power peaks were found to be potentially seventeen times greater than the rated power, flow reversal occurs momentarily during large power oscillations, the fuel centerline temperature oscillates between 1,030 and 2,090 K, while the cladding temperature oscillates between 560 and 570 K. The Suppression Pool reaches its specified temperature limit either never or in as little as 4.3 minutes, depending on operator actions and transient scenario. Thermohydraulic oscillations occur at low core coolant flow (both Recirculation Pumps tripped), with sharp axial or redial fission power peaking and with partial loss of feedwater preheating while the feedwater is flow kept high to maintain coolant inventory in the vessel. Effects from BOP system were shown to influence reactor stability strongly through dosed-loop resonance feedback. High feedwater flow and low temperature destabilize the reactor. Low feedwater flow restabilizes the reactor, because of steam condensation and feedwater preheating in the downcomer, which reduces effectively the destabilizing core inlet subcooling. The EPA has been found to be capable of analyzing BWR stability '' shown to be effective for scoping calculations and for supporting accident management

  15. Serpentine Coil Topology for BNL Direct Wind Superconducting Magnets

    CERN Document Server

    Parker, Brett

    2005-01-01

    BNL direct wind technology, with the conductor pattern laid out without need for extra tooling (no collars, coil presses etc.) began with RHIC corrector production. RHIC patterns were wound flat and then wrapped on cylindrical support tubes. Later for the HERA-II IR magnets we improved conductor placement precision by winding directly on a support tube. To meet HERA-II space and field quality goals took sophisticated coil patterns, (some wound on tapered tubes). We denote such patterns, topologically equivalent to RHIC flat windings, "planar patterns." Multi-layer planar patterns run into trouble because it is hard to wind across existing turns and magnet leads get trapped at poles. So we invented a new "Serpentine" winding style, which goes around 360 degrees while the conductor winds back and forth on the tube. To avoid making solenoidal fields, we wind Serpentine layers in opposite handed pairs. With a Serpentine pattern each turn can have the same projection on the coil axis and integral field harmonics t...

  16. Relativistic quantum mechanics

    CERN Document Server

    Horwitz, Lawrence P

    2015-01-01

    This book describes a relativistic quantum theory developed by the author starting from the E.C.G. Stueckelberg approach proposed in the early 40s. In this framework a universal invariant evolution parameter (corresponding to the time originally postulated by Newton) is introduced to describe dynamical evolution. This theory is able to provide solutions for some of the fundamental problems encountered in early attempts to construct a relativistic quantum theory. A relativistically covariant construction is given for which particle spins and angular momenta can be combined through the usual rotation group Clebsch-Gordan coefficients. Solutions are defined for both the classical and quantum two body bound state and scattering problems. The recently developed quantum Lax-Phillips theory of semigroup evolution of resonant states is described. The experiment of Lindner and coworkers on interference in time is discussed showing how the property of coherence in time provides a simple understanding of the results. Th...

  17. The relativistic Pauli equation

    CERN Document Server

    Delphenich, David

    2012-01-01

    After discussing the way that C2 and the algebra of complex 2x2 matrices can be used for the representation of both non-relativistic rotations and Lorentz transformations, we show that Dirac bispinors can be more advantageously represented as 2x2 complex matrices. One can then give the Dirac equation a form for such matrix-valued wave functions that no longer necessitates the introduction of gamma matrices or a choice for their representation. The minimally-coupled Dirac equation for a charged spinning particle in an external electromagnetic field then implies a second order equation in the matrix-valued wave functions that is of Klein-Gordon type and represents the relativistic analogue of the Pauli equation. We conclude by presenting the Lagrangian form for the relativistic Pauli equation.

  18. Relativistic theories of materials

    CERN Document Server

    Bressan, Aldo

    1978-01-01

    The theory of relativity was created in 1905 to solve a problem concerning electromagnetic fields. That solution was reached by means of profound changes in fundamental concepts and ideas that considerably affected the whole of physics. Moreover, when Einstein took gravitation into account, he was forced to develop radical changes also in our space-time concepts (1916). Relativistic works on heat, thermodynamics, and elasticity appeared as early as 1911. However, general theories having a thermodynamic basis, including heat conduction and constitutive equations, did not appear in general relativity until about 1955 for fluids and appeared only after 1960 for elastic or more general finitely deformed materials. These theories dealt with materials with memory, and in this connection some relativistic versions of the principle of material indifference were considered. Even more recently, relativistic theories incorporating finite deformations for polarizable and magnetizable materials and those in which couple s...

  19. Heavy quarkonium production and polarization

    CERN Document Server

    Kang, Zhong-Bo; Sterman, George

    2011-01-01

    We present a perturbative QCD factorization formalism for the production of heavy quarkonia of large transverse momentum $p_T$ at collider energies, which includes both the leading power (LP) and next-to-leading power (NLP) contributions to the cross section in the $m_Q^2/p_T^2$ expansion for heavy quark mass $m_Q$. We estimate fragmentation functions in the non-relativistic QCD formalism, and reproduce the bulk of the large enhancement found in explicit NLO calculations in the color singlet model. Heavy quarkonia produced from NLP channels prefer longitudinal polarization.

  20. Dynamical phase trajectories for relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Central collisions of gold nuclei are simulated by several existing models and the central net baryon density ρ and the energy density ε are extracted at successive times for beam kinetic energies of 5-40 GeV/nucleon. The resulting trajectories in the (ρ,ε) phase plane are discussed from the perspective of experimentally exploring the expected first-order hadronization phase transition with the planned FAIR at GSI or in a low-energy campaign at the Relativistic Heavy Ion Collider

  1. Relativistic Rotating Vector Model

    CERN Document Server

    Lyutikov, Maxim

    2016-01-01

    The direction of polarization produced by a moving source rotates with the respect to the rest frame. We show that this effect, induced by pulsar rotation, leads to an important correction to polarization swings within the framework of rotating vector model (RVM); this effect has been missed by previous works. We construct relativistic RVM taking into account finite heights of the emission region that lead to aberration, time-of-travel effects and relativistic rotation of polarization. Polarizations swings at different frequencies can be used, within the assumption of the radius-to-frequency mapping, to infer emission radii and geometry of pulsars.

  2. Relativistic electronic dressing

    CERN Document Server

    Attaourti, Y

    2002-01-01

    We study the effects of the relativistic electronic dressing in laser-assisted electron-hydrogen atom elastic collisions. We begin by considering the case when no radiation is present. This is necessary in order to check the consistency of our calculations and we then carry out the calculations using the relativistic Dirac-Volkov states. It turns out that a simple formal analogy links the analytical expressions of the differential cross section without laser and the differential cross section in presence of a laser field.

  3. Open heavy flavor production at RHIC

    CERN Document Server

    Suaide, A A P

    2007-01-01

    The study of heavy flavor production in relativistic heavy ion collisions is an extreme experimental challenge but provides important information on the properties of the Quark-Gluon Plasma (QGP) created in Au+Au collisions at RHIC. Heavy-quarks are believed to be produced in the initial stages of the collision, and are essential on the understanding of parton energy loss in the dense medium created in such environment. Moreover, heavy-quarks can help to investigate fundamental properties of QCD in elementary p+p collisions. In this work we review recent results on heavy flavor production and their interaction with the hot and dense medium at RHIC.

  4. Relativistic Effect in Galaxy Clustering

    OpenAIRE

    Yoo, Jaiyul

    2014-01-01

    The general relativistic description of galaxy clustering provides a complete and unified treatment of all the effects in galaxy clustering such as the redshift-space distortion, gravitational lensing, Sachs-Wolfe effects, and their relativistic effects. In particular, the relativistic description resolves the gauge issues in the standard Newtonian description of galaxy clustering by providing the gauge-invariant expression for the observed galaxy number density. The relativistic effect in ga...

  5. A General Quadrature Solution for Relativistic, Non-relativistic, and Weakly-Relativistic Rocket Equations

    CERN Document Server

    Bruce, Adam L

    2015-01-01

    We show the traditional rocket problem, where the ejecta velocity is assumed constant, can be reduced to an integral quadrature of which the completely non-relativistic equation of Tsiolkovsky, as well as the fully relativistic equation derived by Ackeret, are limiting cases. By expanding this quadrature in series, it is shown explicitly how relativistic corrections to the mass ratio equation as the rocket transitions from the Newtonian to the relativistic regime can be represented as products of exponential functions of the rocket velocity, ejecta velocity, and the speed of light. We find that even low order correction products approximate the traditional relativistic equation to a high accuracy in flight regimes up to $0.5c$ while retaining a clear distinction between the non-relativistic base-case and relativistic corrections. We furthermore use the results developed to consider the case where the rocket is not moving relativistically but the ejecta stream is, and where the ejecta stream is massless.

  6. The Relativistic Rocket

    Science.gov (United States)

    Antippa, Adel F.

    2009-01-01

    We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful…

  7. Relativistic cosmology; Cosmologia Relativista

    Energy Technology Data Exchange (ETDEWEB)

    Bastero-Gil, M.

    2015-07-01

    Relativistic cosmology is nothing but the study of the evolution of our universe expanding from the General Theory of Relativity, which describes the gravitational interaction at any scale and given its character far-reaching is the force that dominate the evolution of the universe. (Author)

  8. Relativistic kinetic momentum operators

    International Nuclear Information System (INIS)

    In the framework of the quantum theory in the relativistic configuration r-space the kinetic momenta, corresponding to the half of the non-Euclidean distance in the Lobachevsky velocities space, are introduced. These operators, coinciding up to the constant factor with the generators of translations of the r-space, are the exterior derivatives of the noncommutative differential calculus

  9. Relativistic Astrophysics; Astrofisica Relativista

    Energy Technology Data Exchange (ETDEWEB)

    Font, J. A.

    2015-07-01

    The relativistic astrophysics is the field of astrophysics employing the theory of relativity Einstein as physical-mathematical model is to study the universe. This discipline analyzes astronomical contexts in which the laws of classical mechanics of Newton's law of gravitation are not valid. (Author)

  10. Relativistic Brueckner-Hartree-Fock theory for finite nuclei

    CERN Document Server

    Shen, Shihang; Liang, Haozhao; Meng, Jie; Ring, Peter; Zhang, Shuangquan

    2016-01-01

    Starting with a bare nucleon-nucleon interaction, for the first time the full relativistic Brueckner-Hartree-Fock equations are solved for finite nuclei in a Dirac-Woods-Saxon basis. No free parameters are introduced to calculate the ground-state properties of finite nuclei. The nucleus $^{16}$O is investigated as an example. The resulting ground-state properties, such as binding energy and charge radius, are considerably improved as compared with the non-relativistic Brueckner-Hartree-Fock results and much closer to the experimental data. This opens the door for \\emph{ab initio} covariant investigations of heavy nuclei.

  11. THEORETICAL CALCULATION OF THE RELATIVISTIC SUBCONFIGURATION-AVERAGED TRANSITION ENERGIES

    Institute of Scientific and Technical Information of China (English)

    张继彦; 杨向东; 杨国洪; 张保汉; 雷安乐; 刘宏杰; 李军

    2001-01-01

    A method for calculating the average energies of relativistic subconfigurations in highly ionized heavy atoms has been developed in the framework of the multiconfigurational Dirac-Fock theory. The method is then used to calculate the average transition energies of the spin-orbit-split 3d-4p transition of Co-like tungsten, the 3d-5f transition of Cu-like tantalum, and the 3d-5f transitions of Cu-like and Zn-like gold samples. The calculated results are in good agreement with those calculated with the relativistic parametric potential method and also with the experimental results.

  12. B -meson decay constants from 2+1 -flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

    Energy Technology Data Exchange (ETDEWEB)

    Christ, N. H.; Flynn, J. M.; Izubuchi, T.; Kawanai, T.; Lehner, C.; Soni, A.; Van de Water, R. S.; Witzel, O.

    2015-03-01

    We calculate the B-meson decay constants fB, fBs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of a0.11, 0.086 fm with unitary pion masses as light as Mπ290MeV; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the b quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the

  13. Coulomb dissociation in nonrelativistic and relativistic collisions

    International Nuclear Information System (INIS)

    Electromagnetic excitations in the Coulomb field of nuclei have been studied using quantum as well as semiclassical methods. Even at relatively modest incident energies, the Coulomb dissociation cross sections of projectiles with relatively low particle thresholds could be of sizeable order of magnitude. Such a study complements our knowledge about radiative capture processes, which are of interest for nuclear astrophysics. Quite a few questions remain to be answered, like the importance of nuclear interactions for small angle scattering, interference of different multipolarities for triple differentiial cross sections and distortion effects on the three-body final states. In the case of dissociation at relativistic energies it is shown that only for the total cross section both semiclassical and quantim-mechanical methods yield the same results. As an example the Primakoff effect is considered, where in an M1 excitation of ≅ 80 MeV a Λ hyperion is converted into a Σo hyperion by means of the virtual photon field of heavy target nuclei. Virtual photon spectra for all multipolarities can be calculated. This provides a sound basis for the analysis of electromagnetic dissociation experiments at relativistic heavy ion accelerators, like the BEVALAC. 10 figs., 25 refs

  14. Measurements of the radioactive inventory of the old effluent pipe line on the BNL site

    International Nuclear Information System (INIS)

    When Berkeley Nuclear Laboratory (BNL) was built, a 3 inch cast iron pipe was laid to carry the radioactive effluent from the BNL effluent treatment plant to the power station for further treatment and/or discharge. In 1980/81 a new pipe line was installed and since then the old line has remained unused. As part of the refurbishment of certain parts of the BNL site currently in progress, the majority of the pipe is to be dug up in two stages, although a small length of the pipe which runs under existing foundations will be left in the ground. This report gives the radioactive inventory of the pipe based on measurements made during the first state of removal. Samples from the trench dug to expose the pipe were taken before and after the removal of the pipe and analysed to determine whether the pipe had leaked and the level of contamination caused by the pipe's removal. (author)

  15. Relativistic Hydrodynamics with Wavelets

    CERN Document Server

    DeBuhr, Jackson; Anderson, Matthew; Neilsen, David; Hirschmann, Eric W

    2015-01-01

    Methods to solve the relativistic hydrodynamic equations are a key computational kernel in a large number of astrophysics simulations and are crucial to understanding the electromagnetic signals that originate from the merger of astrophysical compact objects. Because of the many physical length scales present when simulating such mergers, these methods must be highly adaptive and capable of automatically resolving numerous localized features and instabilities that emerge throughout the computational domain across many temporal scales. While this has been historically accomplished with adaptive mesh refinement (AMR) based methods, alternatives based on wavelet bases and the wavelet transformation have recently achieved significant success in adaptive representation for advanced engineering applications. This work presents a new method for the integration of the relativistic hydrodynamic equations using iterated interpolating wavelets and introduces a highly adaptive implementation for multidimensional simulati...

  16. Relativistic nuclear reactions and the intranuclear cascade method

    International Nuclear Information System (INIS)

    The intranuclear cascade (INC) procedure is analised as a method to describe the processes of relativistic heavy ions collisions. The effects caused by nucleon concentration during the collision are discussed. It is shown explicitly that the occurence of nonbinary collisions among particles is not at all negligible, in spite of the fact that the convencional INC only permits nucleon-nucleon binary collisions. The relativistic invariance of the results obtained by the INC method is discussed. This is especially important when the method is applied for much higher energies. Many of conventional procedures in the method will give certainly different predictions depending on what system of reference is used. The origin of such non-invariance nature of INC calculations is discussed and an alternative way of defining the INC procedure which presents a better credibility with respect to the relativistic invariance property is proposed. (Author)

  17. Kinetic Theory of Radiation in Nonequilibrium Relativistic Plasmas

    CERN Document Server

    Morozov, V G

    2009-01-01

    Many-particle QED is applied to kinetic theory of radiative processes in many- component plasmas with relativistic electrons and nonrelativistic heavy particles. Within the framework of nonequilibrium Green's function technique, transport and mass-shell equations for fluctuations of the electromagnetic field are obtained. We show that the transverse field correlation functions can be decomposed into sharply peaked (non-Lorentzian) parts that describe resonant (propagating) photons and off-shell parts corresponding to virtual photons in plasmas. Analogous decomposi- tions are found for the longitudinal field correlation functions and the correlation functions of relativistic electrons. As a novel result a kinetic equation for the reso- nant photons with a finite spectral width is derived. The off-shell parts of the particle and field correlation functions are shown to be essential to calculate the local ra- diating power in relativistic plasmas and recover the results of vacuum QED. The influence of plasma eff...

  18. Relativistic Viscous Universe Models

    OpenAIRE

    Brevik, Iver; Grøn, Øyvind

    2014-01-01

    The research on relativistic universe models with viscous fluids is reviewed. Viscosity may have been of significance during the early inflationary era, and may also be of importance for the late time evolution of the Universe. Bulk viscosity and shear viscosity cause exponential decay of anisotropy, while nonlinear viscosity causes power-law decay of anisotropy. We consider also the influence from turbulence, in connection with future singularities of the universe (Big Rip and Little Rip). F...

  19. Relativistic quark models

    OpenAIRE

    Simula, Silvano

    2001-01-01

    The application of relativistic constituent quark models to the evaluation of the electromagnetic properties of the nucleon and its resonances is addressed. The role of the pair creation process in the Feynmann triangle diagram is discussed and the importance both of choosing the light-front formalism and of using a Breit frame where the plus component of the four-momentum transfer is vanishing, is stressed. The nucleon elastic form factors are calculated free of spurious effects related to t...

  20. Relativistic spherical plasma waves

    CERN Document Server

    Bulanov, S S; Schroeder, C B; Zhidkov, A G; Esarey, E; Leemans, W P

    2011-01-01

    Tightly focused laser pulses as they diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we report on theoretical study of relativistic spherical wake waves and their properties, including wave breaking. These waves may be suitable as particle injectors or as flying mirrors that both reflect and focus radiation, enabling unique X-ray sources and nonlinear QED phenomena.