WorldWideScience

Sample records for antihyperons

  1. Antihyperon potentials in nuclei via exclusive antiproton-nucleus reactions at FAIR

    CERN Document Server

    Lorente, Alicia Sanchez; Steinen, Marcell; Pochodzalla, Josef

    2015-01-01

    The exclusive production of hyperon-antihyperon pairs close to their production threshold in antiproton - nucleus collisions offers a unique and hitherto unexplored opportunity to elucidate the behaviour of antihyperons in nuclei. For the first time we analyse these reactions in a microscopic transport model using the the Gie\\ss en Boltzmann-Uehling-Uhlenbeck transport model. The calculation take the delicate interplay between the strong absorption of antihyperons, their rescattering and refraction at the nuclear surface as well as the Fermi motion of the struck nucleon into account. We find a substantial sensitivity of transverse momentum correlations of coincident $\\Lambda\\overline{\\Lambda}$-pairs to the assumed depth of the $\\overline{\\Lambda}$-potential. Because of the high cross section for this process and the simplicity of the experimental method our results are highly relevant for future activities at the international Facility for Antiproton and Ion Research (FAIR).

  2. Longitudinal polarization of hyperon and anti-hyperon in semi-inclusive deep-inelastic scattering

    CERN Document Server

    Zhou, Shan-shan; Liang, Zuo-tang; Xu, Qing-hua

    2009-01-01

    We make a detailed study of the longitudinal polarization of hyperons and anti-hyperons in semi-inclusive deep-inelastic lepton-nucleon scattering. We present the numerical results for spin transfer in quark fragmentation processes, analyze the possible origins for a difference between the polarization for hyperon and that for the corresponding anti-hyperon. We present the results obtained in the case that there is no asymmetry between sea and anti-sea distribution in nucleon as well as those obtained when such an asymmetry is taken into account. We compare the results with the available data such as those from COMPASS and make predictions for future experiments including those at even higher energies such as at eRHIC.

  3. Study of {Sigma}(1385) and {Xi}(1321) hyperon and antihyperon production in deep inelastic muon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Schmidt, A. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Alekseev, M.G.; Birsa, R.; Bravar, A.; Dalla Torre, S.; Dasgupta, S.S.; Gobbo, B.; Sozzi, F.; Steiger, L.; Tessaro, S.; Tessarotto, F. [Trieste Section of INFN, Trieste (Italy); Alexakhin, V.Y.; Alexeev, G.D.; Efremov, A.; Gavrichtchouk, O.P.; Gushterski, R.; Guskov, A.; Ivanshin, Y.; Kroumchtein, Z.V.; Kuchinski, N.; Meshcheryakov, G.; Nagaytsev, A.; Olshevsky, A.G.; Rodionov, V.; Rossiyskaya, N.S.; Sapozhnikov, M.G.; Savin, I.A.; Shevchenko, O.Y.; Zemlyanichkina, E.; Zhuravlev, N. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Alexandrov, Y. [Lebedev Physical Institute, Moscow (Russian Federation); Amoroso, A.; Balestra, F.; Bertini, R.; Chiosso, M.; Garfagnini, R.; Gnesi, I.; Grasso, A.; Kotzinian, A.M.; Parsamyan, B.; Piragino, G.; Sosio, S. [University of Turin, Department of Physics (Italy); Torino Section of INFN, Turin (Italy); Austregesilo, A.; Bicker, K. [CERN, Geneva 23 (Switzerland); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Badelek, B. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Barth, J.; Bieling, J.; Goertz, S.; Klein, F.; Panknin, R.; Pretz, J.; Windmolders, R. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Baum, G. [Universitaet Bielefeld, Fakultaet fuer Physik, Bielefeld (Germany); Bedfer, Y.; Burtin, E.; Capozza, L.; Ferrero, A.; Hose, N. d' ; Kunne, F.; Magnon, A.; Marchand, C.; Morreale, A.; Neyret, D.; Platchkov, S.; Thibaud, F.; Vandenbroucke, M.; Wollny, H. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Berlin, A.; Gautheron, F.; Hess, C.; Kisselev, Y.; Koivuniemi, J.H.; Meyer, W.; Reicherz, G.; Wang, L. [Universitaet Bochum, Institut fuer Experimentalphysik, Bochum (Germany); Bernhard, J.; Harrach, D. von; Jasinski, P.; Kabuss, E.; Kang, D.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Schmiden, H. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M. [LIP, Lisbon (Portugal); Bradamante, F.; Bressan, A.; Duic, V.; Elia, C.; Giorgi, M.; Levorato, S.; Martin, A.; Sbrizzai, G.; Schiavon, P. [University of Trieste, Department of Physics (Italy); Trieste Section of INFN, Trieste (Italy); Buechele, M.; Fischer, H.; Guthoerl, T.; Heinsius, F.H.; Herrmann, F.; Koenigsmann, K.; Nerling, F.; Nowak, W.D.; Schill, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Wolbeek, J. ter [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Hoeppner, C.; Huber, S.; Ketzer, B.; Kraemer, M.; Mann, A.; Nagel, T.; Neubert, S.; Paul, S.; Schmitt, L.; Uhl, S. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Cicuttin, A.; Crespo, M.L. [Abdus Salam ICTP, Trieste (Italy); Trieste Section of INFN, Trieste (Italy); Dasgupta, S.; Sarkar, S.; Sinha, L. [Matrivani Institute of Experimental Research and Education, Calcutta (India); Denisov, O.Y.; Maggiora, A.; Takekawa, S. [Torino Section of INFN, Turin (Italy); Donskov, S.V.; Filin, A.; Khaustov, G.V.; Khokhlov, Y.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D. [State Research Center of the Russian Federation, Institute for High Energy Physics, Protvino (Russian Federation); Doshita, N.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Suzuki, H. [Yamagata University, Yamagata (Japan); Duennweber, W.; Faessler, M.; Geyer, R.; Schlueter, T.; Uman, I. [Ludwig-Maximilians-Universitaet Muenchen, Department fuer Physik, Munich (Germany); Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Zaremba, K.; Ziembicki, M. [Warsaw University of Technology, Institute of Radioelectronics, Warsaw (Poland); Finger, M.; Finger, M.; Novy, J. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Du Fresne von Hohenesche, N. [CERN, Geneva 23 (Switzerland); Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Frolov, V.; Mallot, G.K.; Rocco, E.; Schoenning, K.; Schott, M. [CERN, Geneva 23 (Switzerland); Gerassimov, S.; Konorov, I. [Lebedev Physical Institute, Moscow (Russian Federation); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Horikawa, N. [Nagoya University, Nagoya (Japan); Jary, V.; Virius, M. [Czech Technical University in Prague, Prague (Czech Republic); Klimaszewski, K.; Kurek, K.; Rondio, E.; Sandacz, A.; Sulej, R.; Sznajder, P.; Wislicki, W. [National Centre for Nuclear Research, Warsaw (Poland); Kouznetsov, O. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Lichtenstadt, J. [Tel Aviv University, School of Physics and Astronomy, Tel Aviv (Israel); Makke, N. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); University of Trieste, Department of Physics (IT); Trieste Section of INFN, Trieste (IT); Matsuda, T. [University of Miyazaki, Miyazaki (JP); Panzieri, D. [University of Eastern Piedmont, Alessandria (IT); Polak, J. [Technical University in Liberec, Liberec (CZ); University of Trieste, Department of Physics (IT); Trieste Section of INFN, Trieste (IT); Srnka, A. [AS CR, Institute of Scientific Instruments, Brno (CZ); Sulc, M. [Technical University in Liberec, Liberec (CZ); Zavertyaev, M. [Lebedev Physical Institute, Moscow (RU)

    2013-10-15

    Large samples of {Lambda}, {Sigma}(1385) and {Xi}(1321) hyperons produced in the deep-inelastic muon scattering off a {sup 6}LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of {Sigma}(1385){sup +}, {Sigma}(1385){sup -}, anti {Sigma}(1385){sup -}, anti {Sigma}(1385){sup +}, {Xi}(1321){sup -}, and anti {Xi}(1321){sup +} hyperons decaying into {Lambda}(anti {Lambda}){pi} were measured. The ratios of heavy-hyperon to {Lambda} and heavy-antihyperon to anti {Lambda} were found to be in the range 3.8 % to 5.6 % with a relative uncertainty of about 10 %. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator. (orig.)

  4. Study of $\\Sigma$(1385) and $\\Xi$(1321) hyperon and antihyperon production in deep inelastic muon scattering

    CERN Document Server

    Adolph, C; Alexakhin, V.Yu; Alexandrov, Yu.; Alexeev, G D; Amoroso, A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Berlin, A; Bernhard, J; Bertini, R; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Buchele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O.Yu; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M., Jr; Fischer, H; Franco, C; von Hohenesche, N. du Fresne; Friedrich, J M; Frolov, V; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Hoppner, Ch; Horikawa, N; d'Hose, N; Huber, S; Ishimoto, S; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu. A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kuchinski, N; Kunne, F.; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu. V; Miyachi, Y; Morreale, A; Nagaytsev, A; Nagel, T.; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Novy, J; Nowak, W D; Nunes, A.S.; Olshevsky, A G; Ostrick, M; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S.; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Reicherz, G; Rocco, E; Rodionov, V; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S.; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C.; Schluter, T.; Schmidt, A; Schmidt, K; Schmitt, L; Schmiden, H; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O.Yu; Silva, L.; Sinha, L; Sirtl, S; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Sznajder, P; Takekawa, S; Wolbeek, J.Ter; Tessaro, S; Tessarotto, F; Thibaud, F; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Wang, L; Weisrock, T; Wilfert, M; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Zhuravlev, N; Ziembicki, M

    2013-01-01

    Large samples of $\\Lambda$, $\\Sigma(1385)$ and $\\Xi(1321)$ hyperons produced in deep-inelastic muon scattering off a $^6$LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of $\\Sigma(1385)^+$, $\\Sigma(1385)^-$, $\\bar{\\Sigma}(1385)^-$, $\\bar{\\Sigma}(1385)^+$, $\\Xi(1321)^-$, and $\\bar{\\Xi}(1321)^+$ hyperons decaying into $\\Lambda(\\bar{\\Lambda})\\pi$ were measured. The heavy hyperon to $\\Lambda$ and heavy antihyperon to $\\bar{\\Lambda}$ yield ratios were found to be in the range 3.8% to 5.6% with a relative uncertainty of about 10%. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator.

  5. Antihyperon-hyperon production in antiproton-proton annihilations with PANDA at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Papenbrock, Michael [Department of Nuclear Physics and Astronomy, Uppsala University, Uppsala (Sweden); Collaboration: PANDA-Collaboration

    2015-07-01

    The production of antihyperon-hyperon pairs in antiproton-proton annihilations involves the annihilation of at least one light (u,d) quark-antiquark pair and the creation of a heavier (s,c,b) pair. Production of strange hyperons occur in an energy region in which QCD is difficult to predict. By studying hyperon production we learn about the strong interaction in this energy region, i.e. the confinement domain. It is an open question what the relevant degrees of freedom are: quarks and gluons, or hadrons. Spin observables is an excellent tool in order to better understand the physical processes. These are accessible via the weak, parity violating decay of the hyperon which results in an angular asymmetry of the decay products. The future PANDA experiment at FAIR is going to be ideally suited to study spin physics on hyperons with both high precision and high statistics. Since hyperons decay weakly and thus have long life-times, their decay vertices are displaced with respect to the production point. This sets high demands on precise track reconstruction. A pattern recognition algorithm is currently under development, with the ability to reconstruct tracks originating in displaced vertices. Simulation studies done by the Uppsala group as well as the status of the development will be presented and discussed.

  6. Spin observables in antihyperon-hyperon production at P¯ANDA at FAIR

    Science.gov (United States)

    Papenbrock, Michael

    2016-02-01

    Hyperon production is an excellent probe of QCD in the confinement domain, and spin observables are a powerful tool in understanding the underlying physics. For the Ω hyperon, seven polarisation parameters can be extracted from the angular distributions of its decay products with the future P¯ANDA experiment at FAIR. Simulation studies reveal great prospects for strange and single charmed hyperon channels with P¯ANDA. Software tools supporting these investigations are currently under development.

  7. Antihyperon-Hyperon production in antiproton-proton annihilations with PANDA at FAIR

    Science.gov (United States)

    Papenbrock, Michael

    2016-03-01

    Hyperon production is an excellent probe of QCD in the confinement domain, and spin observables are a powerful tool in understanding the underlying physics. For the Ω hyperon, seven polarisation parameters can be extracted from the angular distributions of its decay products with the future PANDA experiment at FAIR. Simulation studies reveal great prospects for strange and single charmed hyperon channels with PANDA. Software tools supporting these investigations are currently under development.

  8. Antihyperon-Hyperon production in antiproton-proton annihilations with PANDA at FAIR

    Directory of Open Access Journals (Sweden)

    Papenbrock Michael

    2016-01-01

    Full Text Available Hyperon production is an excellent probe of QCD in the confinement domain, and spin observables are a powerful tool in understanding the underlying physics. For the Ω hyperon, seven polarisation parameters can be extracted from the angular distributions of its decay products with the future PANDA experiment at FAIR. Simulation studies reveal great prospects for strange and single charmed hyperon channels with PANDA. Software tools supporting these investigations are currently under development.

  9. Recent results on (anti)nucleus and (anti)hyperon production in nucleus-nucleus collisions at CERN SPS energies

    CERN Document Server

    Melkumov, G L; Anticic, T; Baatar, B; Barna, D; Bartke, J; Betev, L; Bialkowska, H; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Buncic, P; Cerny, V; Christakoglou, P; Chung, P; Chvala, O; Cramer, J G; Csató, P; Dinkelaker, P; Eckardt, V; Flierl, D; Fodor, Z; Foka, P; Friese, V; Gál, J; Gazdzicki, M; Genchev, V; Georgopoulos, G; Grebieszkow, K; Hegyi, S; Höhne, C; Kadija, K; Karev, A; Kikola, D; Gladysz-Dziadus, E; Kliemant, M; Kniege, S; Kolesnikov, V I; Kornas, E; Korus, R; Kowalski, M; Kraus, I; Kreps, M; Laszlo, A; Lacey, R; Van Leeuwen, M; Lvai, P; Litov, L; Lungwitz, B; Makariev, M; Malakhov, A I; Mateev, M; Melkumov, G L; Mischke, A; Mitrovski, M; Molnár, J; Mrówczynski, S; Nicolic, V; Pálla, G; Panagiotou, A D; Panayotov, D; Petridis, A; Peryt, W; Pikna, M; Pluta, J; Prindle, D; Pühlhofer, F; Renfordt, R; Roland, C; Roland5, G; Rybczynski, M; Rybicki, A; Sandoval, A; Schmitz, N; Schuster, T; Siklér, F; Sitár, B; Skrzypczak, E; Slodkowski, M; Stefanek, G; Stock, R; Seyboth, P; Strabel, C; Ströbele, H; Susa, T; Szentpetery, I; Sziklai, J; Szuba, M; Szymanski, P; Trubnikov, V; Varga, D; Vassiliou, M; Veres, G I; Vesztergombi, G; Vranic, D; Wlodarczyk, Z; Wojtaszek11, A; Yoo, I K; Zimnyi, J; Wetzler, A

    2007-01-01

    The NA49 experiment has collected comprehensive data on particle production in nucleus-nucleus collisions over the whole SPS beam energies range, the critical energy domain where the expected phase transition to a deconfined phase is expected to occur. The latest results from Pb+Pb collisions between 20$A$ GeV and 158$A$ GeV on baryon stopping and light nuclei production as well as those for strange hyperons are presented. The measured data on $p$, $\\bar{p}$, $\\Lambda$, $\\bar{\\Lambda}$, $\\Xi^-$ and $\\bar{\\Xi}^+$ production were used to evaluate the rapidity distributions of net-baryons at SPS energies and to compare with the results from the AGS and the RHIC for central Pb+Pb (Au+Au) collisions. The dependence of the yield ratios and the inverse slope parameter of the $m_t$ spectra on the collision energy and centrality, and the mass number of the produced nuclei $^3He$, $t$, $d$ and $\\bar{d}$ are discussed within coalescence and statistical approaches. Analysis of the total multiplicity exhibits remarkable a...

  10. Study of Threshold Production of $\\overline{p}p \\rightarrow \\overline{Y}Y$ at LEAR

    CERN Multimedia

    2002-01-01

    Y bar Y $. The channels $ \\bar{\\Lambda} \\Lambda $, $ \\bar{\\Lambda} Sigma ^0 $+c.c., $ Sigma bar sup + Sigma sup + $ and $ Sigma bar sup - Sigma sup - $ are studied. Our aim is to determine quantum numbers of the strange-antistrange quark pair creation which is embedded in these different $ Y bar Y $ channels. In addition, total and differential cross-sections for $\\bar{p}$p$\\rightarrow$ $ K _{s} K _{s} $ are measured.\\\\ \\\\ The data allow for a comparison of decay-asymmetry parameters, partial decay branching ratios and lifetimes of hyperon and antihyperon non-leptonic decays, which can provide tests of fundamental symmetries CP and CPT, respectively. We study also aspects of low-energy $ Y bar Y $ final-state interactions. We can obtain information on hyperon and antihyperon scattering on protons and carbon, including the spin dependence of the cross-section. \\\\ \\\\ The signature of delayed hyperon decays Y$\\rightarrow$N$\\pi$ (or $ K _{s} $ $\\rightarrow

  11. Many Facets of Strangeness Nuclear Physics with Stored Antiprotons

    CERN Document Server

    Pochodzalla, Josef; Lorente, Alicia Sanchez; Rojo, Marta Martinez; Steinen, Marcell; Gerl, Jürgen; Kojouharova, Jasmina; Kojouharova, Ivan

    2016-01-01

    Stored antiprotons beams in the GeV range represent a unparalleled factory for hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of strange hadronic systems with unprecedented precision. The behavior of hyperons and -- for the first time -- of antihyperons in nuclear systems can be studied under well controlled conditions. The exclusive production of $\\Lambda\\bar{\\Lambda}$ and $\\Sigma^-\\bar{\\Lambda}$ pairs in antiproton-nucleus interactions probe the neutron and proton distribution in the nuclear periphery and will help to sample the neutron skin. For the first time, high resolution $\\gamma$-spectroscopy of doubly strange nuclei will be performed, thus complementing measurements of ground state decays of double hypernuclei with mesons beams at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange $\\Xi$-atoms are feasible and even the pr...

  12. Milla Baldo Ceolin (1924-2011)

    CERN Multimedia

    2012-01-01

    At the end of November the particle physics community lost one of its most inquisitive, enthusiastic and active members when Milla Baldo Ceolin, emeritus professor at the University of Padua, passed away after several months of disabling illness.   After graduating from Padua in 1952, Milla began her scientific career in research with balloon-borne nuclear emulsions exposed to cosmic rays in the high atmosphere. Using a pion beam from the Bevatron at Berkeley, in 1958 Milla and D J Prowse discovered the first antihyperon: the antilambda. At the beginning of the 1960s she decided to change detection technique and began experiments with bubble chambers at Argonne, CERN and the Institute for Theoretcial and Experimental Physics (ITEP) in Moscow to investigate selection rules and conservation laws in the kaon system with higher statistics. In the meantime, her group in Padua grew steadily, working in international collaborations. The main field of her investigations changed to neutrino physics ...

  13. Antiproton Production in 11.5A GeV/c Au+Pb Nucleus-Nucleus Collisions

    Energy Technology Data Exchange (ETDEWEB)

    De Cataldo, G.; Giglietto, N.; Raino, A.; Spinelli, P. [University of Bari/INFN, Bari (Italy); Dover, C.B. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Huang, H.Z. [University of California at Los Angeles, Los Angeles, California 90024 (United States); Hill, J.C.; Libby, B.; Wohn, F.K. [Iowa State University, Ames, Iowa 50011 (United States); Rabin, M.S. [University of Massachusetts, Amherst, Massachusetts 01003 (United States); Haridas, P.; Pless, I.A.; Van Buren, G. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Armstrong, T.A.; Lewis, R.A.; Reid, J.D.; Smith, G.A.; Toothacker, W.S. [Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Davies, R.; Hirsch, A.S.; Porile, N.T.; Rimai, A.; Scharenberg, R.P.; Srivastava, B.K.; Tincknell, M.L. [Purdue University, West Lafayette, Indiana 47907 (United States); Greene, S.V. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Bennett, S.J.; Cormier, T.M.; Dee, P.; Fachini, P.; Kim, B.; Li, Q.; Li, Y.; Munhoz, M.G.; Pruneau, C.A.; Wilson, W.K.; Zhao, K. [Wayne State University, Detroit, Michigan 48201 (United States); Barish, K.N.; Bennett, M.J.; Chikanian, A.; Coe, S.D.; Diebold, G.E.; Finch, L.E.; George, N.K.; Kumar, B.S.; Lajoie, J.G.; Majka, R.D.; Nagle, J.L.; Pope, J.K.; Rotondo, F.S.; Sandweiss, J.; Slaughter, A.J.; Wolin, E.J. [Yale University, New Haven, Connecticut 06520 (United States)

    1997-11-01

    We present the first results from the E864 Collaboration on the production of antiprotons in 10{percent} central 11.5A GeV /c Au+Pb nucleus collisions at the Brookhaven Alternating Gradient Synchrotron. We report invariant multiplicities for antiproton production in the kinematic region 1.4{lt}y{lt}2.2 and 50{lt} p{sub T}{lt} 300 MeV/c , and compare our data with a first collision scaling model and previously published results from the E878 Collaboration. The differences between the E864 and E878 antiproton measurements and the implications for antihyperon production are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  14. Reconstructing Hyperons with the ANDA Detector at FAIR

    Science.gov (United States)

    Ikegami Andersson, W.

    2016-08-01

    Hyperon production and the study of their properties is an important part of the physics programme of the future ANDA experiment at FAIR. Antihyperon-hyperon pairs will be produced in antiproton-proton collisions through the annihilation of at least one light antiquark-quark (u, d) pair and the creation of a corresponding number of antiquark-quark s pairs. By measuring the decay products of the hyperons, spin observables such as the polarisation can be measured. Many hyperons have a long life-time which gives rise to final state particles originating from displaced vertices. A pattern recognition algorithm using information from the ANDA Straw Tube Tracker is extended to reconstruct not only the transversal, but also the longitudinal components of charged tracks. A Hough transform and a path finding method as tools to extract the longitudinal components are being developed.

  15. Strangeness in strongly interacting matter

    CERN Document Server

    Greiner, C

    2002-01-01

    This talk is devoted to review the field of strangeness production in (ultra-)relativistic heavy ion collisions within our present theoretical understanding. Historically there have been (at least) three major ideas for the interest in the production of strange hadronic particles: (1) mass modification of the kaons in a (baryon-)dense environment; (2) (early) K+ - production probes the nuclear equation of state (EoS); (3) enhanced strangeness production especially in the (multi-)strange (anti-)baryon channels as a signal of quark gluon plasma (QGP) formation. As a guideline for the discussion I employ the extensive experience with microscopic hadronic transport models. In addition, I elaborate on the recent idea of antihyperon production solely by means of multi-mesonic fusion-type reactions.

  16. First measurements of timelike form factors of the hyperons, Λ0, Σ0, Σ+, Ξ0, Ξ−, and Ω−, and evidence of diquark correlations

    Directory of Open Access Journals (Sweden)

    S. Dobbs

    2014-12-01

    Full Text Available Using 805 pb−1 of e+e− annihilation data taken with the CLEO-c detector at ψ(3770, s=3770 MeV, we report the first measurements of the electromagnetic form factors of the Λ0, Σ0, Σ+, Ξ0, Ξ−, and Ω− hyperons for the large timelike momentum transfer of |Q2|=14.2 GeV2. The form factors for the different hyperons are found to vary by nearly a factor two. It is found that |GM(Λ0|=1.66(24×|GM(Σ0|. The Λ0 and Σ0 hyperons have the same uds quark content, but differ in their isospin, and therefore the spin of the ud quark pair. It is suggested that the spatial correlation implied by the singlet spin–isospin configuration in the Λ0 is an example of strong diquark correlations in the Λ0, as anticipated by Jaffe and Wilczek. Improved measurements of the branching fractions of ψ(2S→pp¯ and hyperon–antihyperon pairs are also reported.

  17. Study of doubly strange systems using stored antiprotons

    Science.gov (United States)

    Singh, B.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, E.; Lisowski, F.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Psyzniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Nicmorus Marinescu, D.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Y. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Olshevskiy, A.; Perevalova, E.; Piskun, A. A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M. G.; Shabratova, G.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopyanov, A.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J. S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M. N.; Wasem, T.; Wohlfarth, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J. C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H. H.; Lin, D.; Maas, F.; Maldaner, S.; Martìnez Rojo, M.; Marta, M.; Michel, M.; Mora Espì, M. C.; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Rodríguez Piñeiro, D.; Sanchez Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, P.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.

    2016-10-01

    Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P ‾ ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ--atoms will be feasible and even the production of Ω--atoms will be within reach. The latter might open the door to the | S | = 3 world in strangeness nuclear physics, by the study of the hadronic Ω--nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions.

  18. Future Perspectives on Baryon Form Factor Measurements with BES III

    Science.gov (United States)

    Schönning, Karin; Li, Cui

    2017-03-01

    The electromagnetic structure of hadrons, parameterised in terms of electromagnetic form factors, EMFF's, provide a key to the strong interaction. Nucleon EMFF's have been studied rigorously for more than 60 years but the new techniques and larger data samples available at modern facilities have given rise to a renewed interest for the field. Recently, the access to hyperon structure by hyperon time-like EMFF provides an additional dimension. The BEijing Spectrometer (BES III) at the Beijing Electron Positron Collider (BEPC-II) in China is the only running experiment where time-like baryon EMFF's can be studied in the e+e- → BB̅ reaction. The BES III detector is an excellent tool for baryon form factor measurements thanks to its near 4π coverage, precise tracking, PID and calorimetry. All hyperons in the SU(3) spin 1/2 octet and spin 3/2 decuplet are energetically accessible within the BEPC-II energy range. Recent data on proton and Λ hyperon form factors will be presented. Furthermore, a world-leading data sample was collected in 2014-2015 for precision measurements of baryon form factors. In particular, the data will enable a measurement of the relative phase between the electric and the magnetic form factors for Λ and Λc+ and hyperons. The modulus of the phase can be extracted from the hyperon polarisation, which in turn is experimentally accessible via the weak, parity violating decay. Furthermore, from the spin correlation between the outgoing hyperon and antihyperon, the sign of the phase can be extracted. This means that the time-like form factors can be completely determined for the first time. The methods will be outlined and the prospects of the BES III form factor measurements will be given. We will also present a planned upgrade of the BES III detector which is expected to improve future form factor measurements.

  19. Gravitational constant is likely dependent on the absolute velocity of galaxy

    Science.gov (United States)

    Chen, Shao-Guang

    quantized inconsecutive time-space-spin using momentum and turn-quantity as the coordinates drawing the momentum-turn graphics are some points with certain distance. The rest mass m _{0} is the lowest energy state advance-back neutrinos pair, when j direction have 2n nuυ _{0} or nuυ (0) , the i , k directions must have (2n-1), (2n+1) nuυ _{0} or nuυ (0) for i, j, k three directions all matching into pair to eliminate the external interaction of electric quantity q (0) in nuυ _{0}. The spatial rest mass is: (n) m _{0} = (2n-1) 2n (2n+1) m (0) = 6, 60, 210, 504, 990 and 1716 m (0) . According to the uncertainty principle n large rest mass layer is more little and at the inside layer of particle. The spatial unit charge quanta e or \\underline{e} are composed by nine one-dimensional unit charge quanta _{0}nuυnuυ (0) or nuυ _{0} (0) nuυ because of the vertical polarization at each spatial direction there is only three states: the left, the right and the middle of left-right balance. With nuυ _{0} ( _{0}nuυ), e (\\underline{e}) and (n) m _{0} ((n) \\underline{m} _{0}) to constitute the muμ antineutrino, muμ neutrino, electro e (-) , and positive electro e (+) . With neutral electron ne(0) ((0) ne) as new unit compose the elementary particles masses (n) m((n) \\underline{m}) = (2n -1) 2n (2n +1) me (\\underline{m}e). The ne(0) ((0) ne) with the rest mass of electron me (\\underline{m}e). The nuυ _{0} ( _{0}nuυ), e ( \\underline{e} ) and (n) m ( (n) \\underline{m} ) to constitute the meson piπ (0) , piπ (-) , piπ (+) , K (0) , \\underline{K} (0) , K (+) , K (-) , nucleons p, \\underline{p}, n , \\underline{n}, hyperons LambdaΛ (0) ,Sigma∑ (0) , Sigma∑ (+) ,Sigma∑ (-) , XiΞ (-) , XiΞ (0) and six anti-hyperons. These particles outside layer at least has one ({2) -1} m ( ({2) -1} \\underline{m}) = 66 me (\\underline{m}e ) of piπ mesons outside layer. The nuclear force is just the direct strong interaction between _{0}nuυ, nuυ_{0}, (0) nuυ, nuυ(0) of

  20. Proceedings of the 28th International Conference on High Energy Physics (in 2 Volumes)

    Science.gov (United States)

    Ajduk, Z.; Wroblewski, A. K.

    1997-04-01

    Photoproduction at HERA * Final State Structure, Fragmentation and Fragmentation Functions * An O(α_s^{2}) Analysis of Event Shape and Orientation in Hadronic Z Decays * Scaling Violations, Fragmentation Functions and q/g Jets at LEP * Inclusive Momentum Distributions of Charged Particles in Jets at CDF * Quark and Gluon Jets * Properties of Leading Particles in Hadronic Z0 Decays * Pa-05 Production and Decays of Heavy Flavours * Top Production and Decay at CDF * DØ Top Quark Cross Section for the 1992-1995 Tevatron Run * Theoretical Aspects of Top Quark Production at Hadron Colliders * Experimental Aspects of Inclusive |Vcb| Measurements * Measurement of |Vcb| from Exclusive Semileptonic B Decays * The Experimental Status of |Vub| * Charm Counting in b-Decays * A Review of B Meson Lifetimes * Lifetimes and Decay Modes of Beauty Baryons * On the Theoretical Understanding of Inclusive Λb Decays * b → Xsγ Decay beyond Leading Logarithms * CLEO Results on Hadronic B Decays * Sum-Rule Results on Exclusive Decays of Heavy Mesons * Leptonic Decays of Charm and Beauty Mesons * Λ_b^{0} Polarization at LEP * New Results on Charm Hadron Decays * Quarkonium Production in poverline p Collisions at the Tevatron * Inclusive b-Quark Production at CDF and DØ * Prompt Quarkonium Production at LEP * Production of Charm at HERA * Measurement of the Observed Inclusive Charm Cross Section in e+e- Interactions at 4.03 GeV * Pa-06 High Energy Nuclear Interactions and Heavy Ion Collisions * The Central Pb-Pb Interactions with Energies 158 GeV/Nucleon * Single-Particle Spectra and Two-Particle-Correlations from PbPb Collisions Measured by NA44 * Particle Correlations in Pb+Pb Collisions at the CERN-SPS - Results from the NA49 Experiment * Single Particle Distributions and Interferometry Results from the WA98 Experiment at CERN * Search for Disoriented Chiral Condensates in 158 AGeV Pb+Pb Collisions * Hyperon and Antihyperon Production in Pb-Pb Collisions at 158A GeV/c * Intriguing Aspects on