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1. Production of deuterium, tritium, andHe3in central Pb + Pb collisions at20A,30A,40A,80A, and158A GeV at the CERN Super Proton Synchrotron

Author

M. Vassiliou, D. J. Prindle, Marek Kowalski, Rainer Arno Ernst Renfordt, E. Skrzypczak, Andras Laszlo, B. Baatar, Gunther Roland, R. Lacey, M. Makariev, Bożena Boimska, G. Pálla, Zbigniew Wlodarczyk, Ferenc Sikler, M. Maćkowiak-Pawłowska, V. I. Kolesnikov, A. Sandoval, T. R. Schuster, P. Seyboth, Z. Fodor, Maciej Rybczyński, T. Antičić, D. Vranic, Gyorgy Vesztergombi, Dezso Varga, H. Ströbele, Latchezar Betev, D. Kresan, M. van Leeuwen, M. K. Mitrovski, C. P. A. Roland, M. Botje, P. Chung, R. Stock, A. Rustamov, Predrag Buncic, Katarzyna Grebieszkow, O. Chvala, J. G. Cramer, Christoph Blume, Andrzej Rybicki, M. Szuba, Kreso Kadija, V. Friese, Marek Gaździcki, Mrowczynski, J. Book, A. Wojtaszek-Szwarc, V. Eckardt, A. Karev, J. Bartke, F. Pühlhofer, Hans Peter Beck, N. Schmitz, Apostolos Panagiotou, Panagiota Foka, T. Susa, G. L. Melkumov, G. Stefanek, Helena Bialkowska, M. Słodkowski, C. Höhne, Alexander Malakhov, Panagiotis Christakoglou, and Gabor Istvan Veres

Subjects
Physics, 010308 nuclear & particles physics, Hadron, Context (language use), 7. Clean energy, 01 natural sciences, Super Proton Synchrotron, Nuclear physics, Helium-3, 0103 physical sciences, Transverse mass, High Energy Physics::Experiment, Production (computer science), Impact parameter, Nuclear Experiment, 010306 general physics, Isotopes of helium
Abstract

Production of $d,\phantom{\rule{0.16em}{0ex}}t$, and $^{3}\mathrm{He}$ nuclei in central $\mathrm{Pb}+\mathrm{Pb}$ interactions was studied at five collision energies ($\sqrt{{s}_{NN}}=6.3$, 7.6, 8.8, 12.3, and 17.3 GeV) with the NA49 detector at the CERN Super Proton Synchrotron. Transverse momentum spectra, rapidity distributions, and particle ratios were measured. Yields are compared to predictions of statistical models. Phase-space distributions of light nuclei are discussed and compared to those of protons in the context of a coalescence approach. The coalescence parameters ${B}_{2}$ and ${B}_{3}$, as well as coalescence radii for $d$ and $^{3}\mathrm{He}$ were determined as a function of transverse mass at all energies.

Published
2016

2. Phase-space dependence of particle-ratio fluctuations in Pb + Pb collisions from 20Ato 158A GeV beam energy

Author

Alexander Malakhov, Christoph Blume, St Mrówczyński, D. J. Prindle, Andrzej Rybicki, Anar Rustamov, Panagiotis Christakoglou, G. Stefanek, H. Ströbele, Marek Kowalski, Gabor Istvan Veres, Dezso Varga, M. Botje, B. Baatar, J. G. Cramer, N. Schmitz, P. Chung, Gunther Roland, R. Stock, Marek Gaździcki, R. Lacey, Gyorgy Vesztergombi, Z. Fodor, A. Wojtaszek-Szwarc, M. Słodkowski, Andras Laszlo, V. I. Kolesnikov, Hans Peter Beck, M. Maćkowiak-Pawłowska, J. Bartke, C. Höhne, T. R. Schuster, G. Pálla, M. Szuba, D. Vranic, Helena Bialkowska, Maciej Rybczyński, T. Antičić, Apostolos Panagiotou, G. L. Melkumov, Panagiota Foka, T. Susa, Zbigniew Wlodarczyk, A. Karev, Bożena Boimska, J. Book, Predrag Buncic, P. Seyboth, Kreso Kadija, F. Pühlhofer, M. Vassiliou, Latchezar Betev, W. Peryt, A. Sandoval, Christof Roland, O. Chvala, E. Skrzypczak, M. Makariev, M. K. Mitrovski, Katarzyna Grebieszkow, V. Eckardt, V. Friese, J. Pluta, Rainer Arno Ernst Renfordt, Ferenc Sikler, D. Kresan, and M. van Leeuwen

Subjects
Nuclear physics, Physics, Excitation function, Nuclear and High Energy Physics, Large Hadron Collider, Pion, Phase space, Electron, Atomic physics, Multiplicity (chemistry), Nuclear Experiment, Super Proton Synchrotron, Particle identification
Abstract

A novel approach, the identity method, was used for particle identification and the study of fluctuations of particle yield ratios in Pb + Pb collisions at the CERN Super Proton Synchrotron (SPS). This procedure allows one to measure the moments of the multiplicity distributions of protons ($p$), kaons ($K$), pions ($\ensuremath{\pi}$), and electrons ($e$) in case of incomplete particle identification. Using these moments the excitation function of the fluctuation measure ${\ensuremath{\nu}}_{\mathrm{dyn}}[A,B]$ was measured, with $A$ and $B$ denoting different particle types. The obtained energy dependence of ${\ensuremath{\nu}}_{\mathrm{dyn}}$ agrees with previously published NA49 results on the related measure ${\ensuremath{\sigma}}_{\mathrm{dyn}}$. However, ${\ensuremath{\nu}}_{\mathrm{dyn}}$[$K$,$p$] and ${\ensuremath{\nu}}_{\mathrm{dyn}}$[$K$,$\ensuremath{\pi}$] were found to depend on the phase-space coverage. This feature most likely explains the reported differences between measurements of NA49 and those of STAR in central Au + Au collisions.

Published
2014

3. Measurements of production properties ofKS0mesons andΛhyperons in proton-carbon interactions at 31 GeV/c

Author

V. I. Kolesnikov, A. Redij, T. Nakadaira, J. Pluta, T. Hasegawa, W. Peryt, A. Ivashkin, D. Kolev, K. Sakashita, M. Maćkowiak-Pawłowska, Sergey Kuleshov, William Brooks, H. Hakobyan, B. Maksiak, R. Tsenov, M. Savic, A. Wojtaszek, J. Blümer, A. Bravar, Alexander Malakhov, L. Zambelli, A. Blondel, N. G. Antoniou, Tivadar Kiss, N. Davis, R. Sipos, Antonio Ereditato, M. Nirkko, M. Unger, M.B. Golubeva, G. A. Feofilov, T. Sekiguchi, Z. Fodor, K. Dynowski, Luigi Salvatore Esposito, Antoni Aduszkiewicz, Ludwik Turko, M. Ravonel, O. Wyszyński, T. Tolyhi, Gyorgy Vesztergombi, A. Marchionni, M. Gazdzicki, S. Puławski, Y. Ali, Mrowczynski, B. A. Popov, T. Palczewski, Jan Kisiel, Leonid Vinogradov, A. Grzeszczuk, Alexey Kurepin, E. Rondio, M. Shibata, P. Christakoglou, T. Kobayashi, W. Rauch, Markus Roth, S. Di Luise, A. Sadovsky, P. Staszel, J. Argyriades, A. S. Kapoyannis, E. Skrzypczak, S. Murphy, A. Marcinek, M. Hierholzer, Stuart Kleinfelder, S. Debieux, N. Katrynska, O. Petukhov, D. Maletic, C. Pistillo, Z. Majka, V. V. Lyubushkin, H-J. Mathes, Katarzyna Grebieszkow, Apostolos Panagiotou, G. L. Melkumov, M. Vassiliou, Zbigniew Wlodarczyk, J. Puzović, A. Wilczek, M. Szuba, D. P. Kikola, André Rubbia, V. Tereshchenko, Viktor Matveev, A. Rustamov, Maciej Rybczyński, T. Antičić, K. Schmidt, O. Busygina, P. Seyboth, Darko Veberič, M. Słodkowski, Vincent Marin, J. Stepaniak, Kreso Kadija, M. Tada, M. Posiada la, T. Drozhzhova, Rainer Arno Ernst Renfordt, Alexey Krasnoperov, D. Kielczewska, Dieter Røhrich, J. Brzychczyk, Ralph Engel, Y. Ivanov, M. Kirejczyk, T. Susa, Fotis K. Diakonos, K. Nishikawa, K. Marton, Anne Robert, S.N. Igolkin, W. Dominik, T. Paul, A. Korzenev, H. Dembinski, V. P. Kondratiev, E. Kaptur, A. Haesler, Vladimir Vechernin, T. Matulewicz, S. Kowalski, Ágnes Fülöp, Andras Laszlo, G. Pálla, D. Joković, F.F. Guber, W. Zipper, D. T. Larsen, Tobiasz Czopowicz, D. Manić, N. Abgrall, J. Dumarchez, S.A. Bunyatov, M. Bogomilov, G. Stefanek, R. Płaneta, R. Idczak, B. Baatar, and Ralf Ulrich

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Hyperon, Strangeness production, 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, Nuclear interaction length, High Energy Physics::Experiment, Neutrino, Nuclear Experiment, 010306 general physics, Neutrino oscillation
Abstract

Spectra of KS0 mesons and Λ hyperons were measured in p + C interactions at 31 GeV/c with the large acceptance NA61/SHINE spectrometer at the CERN SPS. The data were collected with an isotropic graphite target with a thickness of 4% of a nuclear interaction length. Interaction cross sections, charged pion spectra, and charged kaon spectra were previously measured using the same data set. Results on KS0 and Λ production in p + C interactions serve as a reference for the understanding of the enhancement of strangeness production in nucleus-nucleus collisions. Moreover, they provide important input for the improvement of neutrino flux predictions for the T2K long baseline neutrino oscillation experiment in Japan. Inclusive production cross sections for KS0 and Λ are presented as a function of laboratory momentum in intervals of the laboratory polar angle covering the range from 0 up to 240 mrad. The results are compared with predictions of several hadron production models. The KS0 mean multiplicity in production processes 〈nKS0〉 and the inclusive cross section for KS0 production σKS0 were measured and amount to 0.127 ± 0.005 (stat) ± 0.022 (sys) and 29.0 ± 1.6 (stat) ± 5.0 (sys) mb, respectively. © 2014 American Physical Society.

Published
2014

4. K*(892)0andK¯*(892)0production in central Pb+Pb, Si+Si, C+C, and inelasticp+pcollisions at 158AGeV

Author

Christof Roland, O. Chvala, D. J. Prindle, Marek Kowalski, Panagiotis Christakoglou, E. Skrzypczak, D. Kresan, M. van Leeuwen, Gabor Istvan Veres, R. Lacey, M. Utvić, N. Schmitz, M. Bogusz, Rainer Arno Ernst Renfordt, F. Pühlhofer, J. G. Cramer, A. Karev, Marek Gaździcki, A. Wojtaszek-Szwarc, Latchezar Betev, G. Stefanek, Alexander Malakhov, Gyorgy Vesztergombi, W. Peryt, P. Chung, Andras Laszlo, Christoph Blume, D. Barna, R. Stock, J. Bartke, Andrzej Rybicki, G. Pálla, M. Makariev, Ferenc Sikler, T. R. Schuster, M. Botje, J. Book, Zbigniew Wlodarczyk, Predrag Buncic, M. K. Mitrovski, M. Słodkowski, Tatjana Susa, Katarzyna Grebieszkow, M. Vassiliou, C. Höhne, Tome Anticic, T. Cetner, V. Friese, Hans Peter Beck, V. Eckardt, V. I. Kolesnikov, Panagiota Foka, P. Seyboth, D. Vranic, M. Szuba, Dezso Varga, Kreso Kadija, Gunther Roland, Helena Bialkowska, Z. Fodor, H. Ströbele, M. Mackowiak, A. Sandoval, M. Mateev, Bożena Boimska, Apostolos Panagiotou, V. Nicolic, G. L. Melkumov, Maciej Rybczyński, B. Baatar, St Mrówczyński, and J. Pluta

Subjects
Physics, Nuclear and High Energy Physics, Silicon, 010308 nuclear & particles physics, Nuclear Theory, Hadron, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Nuclear physics, chemistry, Yield (chemistry), Phase (matter), 0103 physical sciences, Transverse momentum, High Energy Physics::Experiment, Rapidity, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

Production of the K*(892)0 and K*(892)⁰ resonances was studied via their K⁺π⁻ and K⁻π⁺ decay modes in central Pb+Pb, Si+Si, C+C, and inelastic p+p collisions at 158A GeV(√(sNN)=17.3 GeV) with the NA49 detector at the CERN SPS. Transverse momentum and rapidity distributions were measured and total yields were estimated. The yield of K* exceeds that of K* by about a factor of two in nucleus-nucleus reactions. The total yield ratios ⟨K*⟩/⟨K+⟩ and ⟨K*⟩/⟨K-⟩ are strongly suppressed in central Pb+Pb compared to p+p, C+C, and Si+Si collisions, in agreement with the expected attenuation of these short-lived resonance states in the hadronic phase of the expanding fireball. The UrQMD model, although incorporating such a scenario, does not provide a quantitative description of the experimental results. The statistical hadron gas model assuming the same freeze-out parameters for stable hadrons and resonances overestimates the ⟨K*⟩/⟨K⟩ ratios in central Pb+Pb collisions by about a factor of 2.5.

Published
2011

5. Energy dependence of kaon-to-proton ratio fluctuations in centralPb+Pbcollisions fromsNN=6.3to 17.3 GeV

Author

Panagiotis Christakoglou, Andras Laszlo, Gabor Istvan Veres, G. Pálla, Predrag Buncic, Christoph Blume, Andrzej Rybicki, A. Sandoval, M. Mateev, M. Botje, Thorsten Sven Kollegger, Tatjana Susa, Dezso Varga, M. Utvić, M. Słodkowski, Hans Peter Beck, M. Mackowiak, Zbigniew Wlodarczyk, H. Ströbele, J. Pluta, T. Cetner, M. K. Mitrovski, P. Seyboth, R. Lacey, F. Pühlhofer, Katarzyna Grebieszkow, Z. Fodor, W. Peryt, G. Stefanek, V. Friese, St Mrówczyński, M. Makariev, Maciej Rybczyński, E. Skrzypczak, A. Wojtaszek-Szwarc, B. Baatar, Christof Roland, J. Book, Alexander Malakhov, Panagiota Foka, N. Schmitz, V. I. Kolesnikov, O. Chvala, C. Höhne, Gyorgy Vesztergombi, J. Bartke, M. Bogusz, D. Vranic, P. Chung, V. Eckardt, R. Stock, J. G. Cramer, Marek Gaździcki, Rainer Arno Ernst Renfordt, Latchezar Betev, Ferenc Sikler, D. Kresan, M. van Leeuwen, Gunther Roland, Bożena Boimska, V. Nicolic, T. R. Schuster, A. Karev, Apostolos Panagiotou, G. L. Melkumov, D. J. Prindle, D. Barna, Marek Kowalski, M. Szuba, Helena Bialkowska, Kreso Kadija, M. Vassiliou, and Tome Anticic

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, Proton, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Strangeness, 01 natural sciences, Super Proton Synchrotron, Nuclear physics, Baryon, 0103 physical sciences, High Energy Physics::Experiment, Baryon number, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Kaons and protons carry large parts of two conserved quantities: strangeness and baryon number. It is argued that their correlation and thus also fluctuations are sensitive to conditions prevailing at the anticipated parton-hadron phase boundary. Fluctuations of the (K++K-)/(p+p ) and K+/p ratios have been measured for the first time by NA49 in central Pb+Pb collisions at five CERN Super Proton Synchrotron energies between √sNN=6.3 and √sNN=17.3 GeV. Both ratios exhibit a change of sign in σdyn, a measure of nonstatistical fluctuations, around √sNN=8 GeV. Below this energy, σdyn is positive, indicating higher fluctuation compared to a mixed event background sample, while for higher energies, σdyn is negative, indicating correlated emission of kaons and protons. The results are compared to hadronic transport model calculations which fail to reproduce the energy dependence.

Published
2011

6. Centrality dependence of proton and antiproton spectra in Pb+Pb collisions at40AGeV and158AGeV measured at the CERN Super Proton Synchrotron

Author

R. Lacey, N. Schmitz, M. Bogusz, D. J. Prindle, Rainer Arno Ernst Renfordt, Panagiota Foka, Panagiotis Christakoglou, Marek Kowalski, B. Baatar, M. Słodkowski, Gabor Istvan Veres, M. Gazdzicki, T. Cetner, A. Karev, Ferenc Sikler, D. Barna, D. Kresan, H. Ströbele, F. Pühlhofer, M. K. Mitrovski, Christof Roland, T. R. Schuster, M. Vassiliou, Helena Bialkowska, M. van Leeuwen, J. Pluta, Z. Fodor, Gunther Roland, Hans Peter Beck, Katarzyna Grebieszkow, Tome Anticic, W. Peryt, P. Seyboth, P. Chung, R. Stock, A. Sandoval, V. I. Kolesnikov, Christoph Blume, Andrzej Rybicki, O. Chvala, Alexander Malakhov, D. Vranic, Zbigniew Wlodarczyk, Kreso Kadija, Maciej Rybczyński, M. Botje, A. Wojtaszek-Szwarc, Gyorgy Vesztergombi, M. Mateev, Latchezar Betev, J. Book, E. Skrzypczak, Apostolos Panagiotou, J. Bartke, M. Mackowiak, G. L. Melkumov, St Mrówczyński, M. Utvić, J. G. Cramer, M. Makariev, M. Szuba, V. Eckardt, Tatjana Susa, Predrag Buncic, Andras Laszlo, G. Pálla, V. Nicolic, C. Hohne, G. Stefanek, Dezso Varga, and Bożena Boimska

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Time projection chamber, Proton, 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, Super Proton Synchrotron, Nuclear physics, Antiproton, Antimatter, 0103 physical sciences, Transverse mass, Rapidity, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The yields of (anti)protons were measured by the NA49 Collaboration in centrality-selected Pb + Pb collisions at 40A and 158A GeV. Particle identification was obtained in the laboratory momentum range from 5 to 63 GeV/c by measuring the energy loss dE/dx in the time projection chamber detector gas. The corresponding rapidity coverage extends 1.6 units from midrapidity into the forward hemisphere. Transverse-mass spectra, the rapidity dependences of the average transverse mass, and rapidity density distributions were studied as a function of collision centrality. The values of the average transverse mass as well as the midrapidity yields of protons normalized to the number of wounded nucleons show only modest centrality dependences. In contrast, the shape of the rapidity distribution changes significantly with collision centrality, especially at 40A GeV. The experimental results are compared to calculations of the hadron-string dynamics and the ultrarelativistic quantum-molecular-dynamics transport models.

Published
2011

7. System-size dependence ofΛandΞproduction in nucleus-nucleus collisions at40Aand158AGeV measured at the CERN Super Proton Synchrotron

Author

T. Anticic, B. Baatar, D. Barna, J. Bartke, H. Beck, L. Betev, H. Białkowska, C. Blume, B. Boimska, J. Book, M. Botje, J. Bracinik, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kresan, V. I. Kolesnikov, M. Kowalski, I. Kraus, M. Kreps, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, C. Meurer, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, M. Utvić, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, Z. Włodarczyk, A. Wojtaszek, and I. K. Yoo

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Elementary particle, Lambda baryon, 7. Clean energy, 01 natural sciences, Super Proton Synchrotron, Xi baryon, Nuclear physics, 0103 physical sciences, Transverse mass, Rapidity, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Results on Λ, Λ , and Ξ- production in centrality selected Pb+Pb reactions at 40A and 158A GeV and in near-central C+C and Si+Si reactions at 158A GeV are presented. Transverse mass spectra, rapidity spectra, and multiplicities in dependence of the system size are discussed. Comparisons to transport models (ultrarelativistic quantum molecular dynamics and hadron string dynamics) and to the core-corona approach are performed. Although Λ and Λ production can be described by transport models reasonably well, these models do not agree with the Ξ- measurements. However, the core-corona picture fits very well the system-size dependence of Λ and Ξ-, whereas it agrees less well with the Λ data.

Published
2009

8. Energy dependence of particle ratio fluctuations in centralPb+Pbcollisions fromsNN=6.3to 17.3 GeV

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčcić, V. Cerny, P. Christakoglou, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, M. Kliemant, S. Kniege, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, D. Kresan, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, M. Pikna, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, G. Stefanek, R. Stock, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, and I. K. Yoo

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Meson, Proton, 010308 nuclear & particles physics, Hadron, Elementary particle, Fermion, Statistical fluctuations, 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

We present measurements of the energy dependence of event-by-event fluctuations in the K/{pi} and (p+p)/{pi} multiplicity ratios in heavy-ion collisions at the CERN SPS. The particle ratio fluctuations were obtained for central Pb+Pb collisions at five collision energies, {radical}(s{sub NN}), between 6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics and detector resolution, we extract the strength of nonstatistical fluctuations at each energy. For the K/{pi} ratio, larger fluctuations than expected for independent particle production are found at all collision energies. The fluctuations in the (p+p)/{pi} ratio are smaller than expectations from independent particle production, indicating correlated pion and proton production from resonance decays. For both ratios, the deviation from purely statistical fluctuations shows an increase toward lower collision energies. The results are compared to transport model calculations, which fail to describe the energy dependence of the K/{pi} ratio fluctuations.

Published
2009

9. Energy dependence of transverse momentum fluctuations inPb+Pbcollisions at the CERN Super Proton Synchrotron (SPS) at20Ato158AGeV

Author

T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, M. Kreps, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, M. Utvic, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, Z. Włodarczyk, A. Wojtaszek, and I. K. Yoo

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, 01 natural sciences, Super Proton Synchrotron, Charged particle, Nuclear physics, Baryon, Critical point (thermodynamics), 0103 physical sciences, Rapidity, Multiplicity (chemistry), Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Results are presented on event-by-event fluctuations of transverse momenta p{sub T} in central Pb+Pb interactions at 20A, 30A, 40A, 80A, and 158A GeV. The analysis was performed for charged particles at forward center-of-mass rapidity (1.1

Published
2009

10. Energy dependence ofϕmeson production in centralPb+Pbcollisions atsNN=6to 17 GeV

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, M. Kliemant, S. Kniege, V. I. Kolesnikov, T. Kollegger, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, D. Kresan, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, I. K. Yoo, and J. Zimányi

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson production, Isotope, 010308 nuclear & particles physics, Degrees of freedom (physics and chemistry), 7. Clean energy, 01 natural sciences, Nuclear physics, 0103 physical sciences, Thermal, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Beam energy, Energy (signal processing)
Abstract

{phi} meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and with microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies.

Published
2008

11. Energy dependence of Λ and Ξ production in centralPb+Pbcollisions at20A,30A,40A,80A, and 158AGeV measured at the CERN Super Proton Synchrotron

Author

M. Makariev, M. K. Mitrovski, Katarzyna Grebieszkow, V. Friese, D. J. Prindle, B. Baatar, J. Pluta, Andreas Petridis, Alexander Malakhov, M. van Leeuwen, Marek Kowalski, M. Słodkowski, Gyorgy Vesztergombi, H. Ströbele, Christof Roland, D. Barna, Zbigniew Wlodarczyk, Mrowczynski, E. Gladysz, P. Dinkelaker, Michal Kreps, A. Richard, M. Szuba, M. Botje, Miroslav Pikna, Jozsef Molnar, R. Lacey, I. Kraus, P. Christakoglou, J. Zimányi, Andre Mischke, A. Wetzler, P. Csato, J. Gál, P. Chung, E. Kornas, C. Meurer, J. Sziklai, R. Stock, Gunther Roland, R. Bramm, Apostolos Panagiotou, O. Chvala, M. Utvić, B. Lungwitz, P. Seyboth, Predrag Buncic, G. L. Melkumov, D. Panayotov, D. Flierl, P. Szymanski, A. Karev, Bożena Boimska, Peter Levai, Branislav Sitar, Z. Fodor, F. Pühlhofer, J. Bracinik, T. R. Schuster, C. Strabel, Panagiota Foka, Helena Bialkowska, T. Susa, V. Eckardt, Leander Litov, Kreso Kadija, I. K. Yoo, V. Cerny, J. Bartke, V. Trubnikov, W. Peryt, Gabor Istvan Veres, V. Genchev, C. Alt, G. Stefanek, Andras Laszlo, A. Sandoval, M. Mateev, M. Vassiliou, V. Nicolic, C. Höhne, Christoph Blume, E. Skrzypczak, Andrzej Rybicki, G. Pálla, Rainer Arno Ernst Renfordt, M. Kliemant, Dezso Varga, N. Schmitz, M. Gazdzicki, A. Wojtaszek, Ferenc Sikler, S. Hegyi, Latchezar Betev, D. P. Kikola, I. Szentpetery, J. G. Cramer, Maciej Rybczyński, T. Antičić, S. Kniege, V. I. Kolesnikov, and D. Vranic

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Elementary particle, Lambda baryon, 7. Clean energy, 01 natural sciences, Super Proton Synchrotron, Xi baryon, Nuclear physics, Baryon, 0103 physical sciences, Transverse mass, Rapidity, Nuclear Experiment, 010306 general physics
Abstract

Results on {lambda},{lambda},{xi}{sup -}, and {xi}{sup +} production in central Pb+Pb reactions at 20A,30A,40A,80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. Although the latter provide a reasonable description of all particle yields, the first class of models fails to match the {xi}{sup -} and {xi}{sup +} multiplicities.

Published
2008

12. Energy dependence of multiplicity fluctuations in heavy ion collisions at20Ato158AGeV

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, M. Kliemant, S. Kniege, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, M. Utvic, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, and J. Zimányi

Subjects
Physics, Nuclear and High Energy Physics, Conservation law, 010308 nuclear & particles physics, Hadron, Elementary particle, 01 natural sciences, Charged particle, Nuclear physics, Critical point (thermodynamics), 0103 physical sciences, Quark–gluon plasma, Rapidity, Multiplicity (chemistry), Nuclear Experiment, 010306 general physics
Abstract

Multiplicity fluctuations of positively, negatively, and all charged hadrons in the forward hemisphere were studied in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV. The multiplicity distributions and their scaled variances ω are presented as functions of their dependence on collision energy as well as on rapidity and transverse momentum. The distributions have bell-like shapes and their scaled variances are in the range from 0.8 to 1.2 without any significant structure in their energy dependence. No indication of the critical point in fluctuations are observed. The string-hadronic ultrarelativistic quantum molecular dynamics (UrQMD) model significantly overpredicts the mean, but it approximately reproduces the scaled variance of the multiplicity distributions. The predictions of the statistical hadron-resonance gas model obtained within the grand-canonical and canonical ensembles disagree with the measured scaled variances. The narrower than Poissonian multiplicity fluctuations measured in numerous cases may be explained by the impact of conservation laws on fluctuations in relativistic systems.

Published
2008

13. Bose-Einstein correlations ofπ−π−pairs in central Pb+Pb collisions at20A,30A,40A,80A, and158AGeV

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, M. Kliemant, S. Kniege, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, and J. Zimányi

Subjects
Physics, Nuclear and High Energy Physics, Meson, Proton, 010308 nuclear & particles physics, Hadron, Radius, Bose–Einstein correlations, 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, Rapidity, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Measurements of Bose-Einstein correlations of {pi}{sup -}{pi}{sup -} pairs in central Pb+Pb collisions were performed with the NA49 detector at the CERN Super Proton Synchroton for beam energies of 20A,30A,40A,80A, and 158A GeV. Correlation functions were measured in the longitudinally comoving 'out-side-long' reference frame as a function of rapidity and transverse momentum in the forward hemisphere of the reaction. Radius and correlation strength parameters were obtained from fits of a Gaussian parametrization. The results show a decrease of the radius parameters with increasing transverse-momentum characteristic of strong radial flow in the pion source. No striking dependence on pion-pair rapidity or beam energy is observed. Static and dynamic properties of the pion source are obtained from simultaneous fits with a blast-wave model to radius parameters and midrapidity transverse-momentum spectra. Predictions of hydrodynamic and microscopic models of Pb+Pb collisions are discussed.

Published
2008

14. High transverse momentum hadron spectra atsNN=17.3GeV inPb+Pbandp+pcollisions

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, M. Kliemant, S. Kniege, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, A. László, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, and J. Zimányi

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Modification factor, 01 natural sciences, Spectral line, Nuclear physics, 0103 physical sciences, Transverse momentum, Saturation (graph theory), Nuclear Experiment, 010306 general physics, Relativistic Heavy Ion Collider, Energy (signal processing)
Abstract

Transverse momentum spectra up to 4.5 GeV/c around midrapidity of {pi}{sup {+-}},p,p, and K{sup {+-}} in Pb+Pb reactions were measured at {radical}(s{sub NN})=17.3 GeV by the CERN-NA49 experiment. The nuclear modification factors R{sub AA} for {pi}{sup {+-}} and R{sub CP} for {pi}{sup {+-}},p,p,K{sup {+-}} were extracted and compared with results obtained at the BNL Relativistic Heavy Ion Collider (RHIC) at {radical}(s{sub NN})=200 GeV. The modification factor R{sub AA} shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor R{sub CP}, in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the {pi}{sup {+-}} channel. The extracted R{sub CP} values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for {pi}{sup {+-}} above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.

Published
2008

15. Pion and kaon production in centralPb+Pbcollisions at20Aand30AGeV: Evidence for the onset of deconfinement

Author

Rainer Arno Ernst Renfordt, C. Strabel, Michal Kreps, Mrowczynski, C. Alt, A. Karev, F. Pühlhofer, V. Cerny, W. Peryt, A. Wetzler, Ferenc Sikler, E. Skrzypczak, Andre Mischke, D. P. Kikola, Predrag Buncic, Gunther Roland, J. Gál, Zbigniew Wlodarczyk, Gyorgy Vesztergombi, Branislav Sitar, Miroslav Pikna, P. Seyboth, Christoph Blume, Andrzej Rybicki, Panagiota Foka, C. Höhne, J. G. Cramer, M. K. Mitrovski, M. van Leeuwen, Christof Roland, Leander Litov, R. Lacey, B. Lungwitz, Katarzyna Grebieszkow, Latchezar Betev, D. Barna, P. Christakoglou, I. Kraus, J. Pluta, Andreas Petridis, P. Szymanski, Kreso Kadija, Gabor Istvan Veres, V. Friese, M. Kliemant, M. Makariev, O. Chvala, Thorsten Sven Kollegger, E. Kornas, M. Szuba, Apostolos Panagiotou, D. Flierl, V. I. Kolesnikov, G. L. Melkumov, B. Baatar, J. Sziklai, R. Bramm, P. Csato, P. Chung, S. Hegyi, R. Stock, D. Vranic, M. Slodkowski, M. Gazdzicki, D. Panayotov, N. Schmitz, D. J. Prindle, J. Zimányi, Z. Fodor, V. Trubnikov, J. Bracinik, V. Eckardt, Jozsef Molnar, Marek Kowalski, Helena Bialkowska, M. Vassiliou, Alexander Malakhov, E. Gladysz, P. Dinkelaker, Tome Anticic, T. R. Schuster, I. K. Yoo, J. Bartke, H. Ströbele, S. Kniege, Maciej Rybczyński, Tatjana Susa, A. Sandoval, M. Mateev, Bożena Boimska, Peter Levai, V. Nicolic, I. Szentpetery, Andras Laszlo, G. Pálla, M. Botje, V. Genchev, G. Stefanek, and Dezso Varga

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, Proton, 010308 nuclear & particles physics, Nuclear Theory, Hadron, 01 natural sciences, 7. Clean energy, Deconfinement, Nuclear physics, Strange matter, Pion, 0103 physical sciences, Transverse mass, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.

Published
2008

16. Rapidity and energy dependence of the electric charge correlations inA+Acollisions from20Ato158AGeV

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Bunčić, V. Cerny, P. Christakoglou, P. Chung, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, D. Kikola, M. Kliemant, S. Kniege, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, A. Laszlo, R. Lacey, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, W. Peryt, M. Pikna, J. Pluta, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, M. Slodkowski, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, M. Szuba, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, and J. Zimányi

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Jet (particle physics), 01 natural sciences, Electric charge, Super Proton Synchrotron, Hadronization, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, 010306 general physics, Nucleon, Relativistic Heavy Ion Collider
Abstract

Results from electric charge correlations studied with the Balance Function (BF) method in A+A collisions from 20A to 158A GeV are presented in two different rapidity intervals: In the midrapidity region we observe a decrease of the width of the BF distribution with increasing centrality of the collision, whereas this effect vanishes in the forward rapidity region. Results from the energy dependence study in central Pb+Pb collisions show that the narrowing of the BF expressed by the normalized width parameter W increases with energy toward the highest CERN Super Proton Synchrotron and BNL Relativistic Heavy Ion Collider energies. Finally we compare our experimental data points with the predictions of several models. The hadronic string models Ultra-relativistic Quantum Molecular Dynamics and Heavy Ion Jet INteraction Generator (HIJING) do not reproduce the observed narrowing of the BF. However, A MultiPhase Transport medel (AMPT), which contains a quark-parton transport phase before hadronization, can reproduce the narrowing of the BF's width with centrality. This confirms the proposed sensitivity of the BF analysis to the time of hadronization.

Published
2007

17. Energy and centrality dependence ofp¯andpproduction and theΛ¯/p¯ratio in Pb+Pb collisions between 20AGeV and 158AGeV

Author

C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, J. Bracinik, R. Bramm, P. Buncić, V. Cerny, P. Christakoglou, O. Chvala, J. G. Cramer, P. Csató, P. Dinkelaker, V. Eckardt, D. Flierl, Z. Fodor, P. Foka, V. Friese, J. Gál, M. Gaździcki, V. Genchev, G. Georgopoulos, E. Gładysz, K. Grebieszkow, S. Hegyi, C. Höhne, K. Kadija, A. Karev, M. Kliemant, S. Kniege, V. I. Kolesnikov, E. Kornas, R. Korus, M. Kowalski, I. Kraus, M. Kreps, A. Laslo, M. van Leeuwen, P. Lévai, L. Litov, B. Lungwitz, M. Makariev, A. I. Malakhov, M. Mateev, G. L. Melkumov, A. Mischke, M. Mitrovski, J. Molnár, St. Mrówczyński, V. Nicolic, G. Pálla, A. D. Panagiotou, D. Panayotov, A. Petridis, M. Pikna, D. Prindle, F. Pühlhofer, R. Renfordt, C. Roland, G. Roland, M. Rybczyński, A. Rybicki, A. Sandoval, N. Schmitz, T. Schuster, P. Seyboth, F. Siklér, B. Sitar, E. Skrzypczak, G. Stefanek, R. Stock, C. Strabel, H. Ströbele, T. Susa, I. Szentpétery, J. Sziklai, P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, I. K. Yoo, and J. Zimányi

Subjects
Nuclear reaction, Physics, Nuclear physics, Nuclear and High Energy Physics, Proton, Antiproton, Antimatter, Hadron, Transverse mass, Rapidity, Atomic physics, Nuclear Experiment, Lambda baryon
Abstract

The transverse mass m{sub t} distributions for antiprotons are measured at midrapidity for minimum bias Pb+Pb collisions at 158A GeV and for central Pb+Pb collisions at 20A, 30A, 40A, and 80A GeV beam energies in the fixed target experiment NA49 at the CERN SPS. The rapidity density dn/dy, inverse slope parameter T, and mean transverse mass derived from the m{sub t} distributions are studied as a function of the incident energy and the collision centrality and compared to the relevant data on proton production. The shapes of the m{sub t} distributions of p and p are very similar. The ratios of the particle yields, p/p and {lambda}/p, are also analyzed. The p/p ratio exhibits an increase with decreasing centrality and a steep rise with increasing beam energy. The {lambda}/p ratio increases beyond unity with decreasing beam energy.

Published
2006

18. System size and centrality dependence of the balance function inA+Acollisions atsNN=17.2GeV

Author

A. Richard, Miroslav Pikna, R. Korus, P. Christakoglou, J. G. Cramer, E. Kornas, Gunther Roland, A. Wetzler, Thorsten Sven Kollegger, B. Baatar, Zbigniew Wlodarczyk, A. Billmeier, Christina Markert, Leander Litov, Anton Dimitrov, Rainer Arno Ernst Renfordt, B. Lungwitz, V. Eckardt, D. Flierl, P. Seyboth, Marek Gaździcki, St Mrówczyński, Gyorgy Vesztergombi, P. Freund, Dezso Varga, Andreas Petridis, H. Ströbele, Jozsef Molnar, Branislav Sitar, S. Kniege, Panagiota Foka, T. Susa, Gabor Istvan Veres, Bożena Boimska, Peter Levai, N. Darmenov, A. Karev, F. Pühlhofer, M. K. Mitrovski, Katarzyna Grebieszkow, Kreso Kadija, Latchezar Betev, H. Sann, J. Zaranek, V. Friese, N. Schmitz, G. Farantatos, M. Makariev, V. Cerny, Ferenc Sikler, C. Alt, P. Csato, Michal Kreps, R. Stock, Alexander Malakhov, D. Panayotov, A. Sandoval, I. K. Yoo, M. Mateev, G. Pálla, B. W. Mayes, Christof Roland, Maciej Rybczyński, T. Antičić, J. Bartke, A. Rybicki, G. Stefanek, M. van Leeuwen, I. Kraus, E. Skrzypczak, J. Zimányi, Z. Fodor, C. Meurer, J. Bracinik, O. Chvala, M. Botje, I. Szentpetery, V. Trubnikov, V. I. Kolesnikov, M. Kliemant, Jeffrey G. Reid, D. Vranic, G. Georgopoulos, M. Vassiliou, R. Bramm, Predrag Buncic, S. Hegyi, Christoph Blume, Rene Brun, Apostolos Panagiotou, G. L. Melkumov, Helena Bialkowska, L. S. Pinsky, Marek Kowalski, C. Höhne, Andre Mischke, E. Gladysz, P. Dinkelaker, D. Barna, J. Sziklai, and J. Gál

Subjects
Physics, Nuclear and High Energy Physics, Hadron, Elementary particle, Electric charge, Charged particle, Hadronization, Baryon, Nuclear physics, Pseudorapidity, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Nucleon
Abstract

Electric charge correlations were studied for p+p, C+C, Si+Si, and centrality selected Pb+Pb collisions at {radical}(s{sub NN})=17.2 GeV with the NA49 large acceptance detector at the CERN SPS. In particular, long-range pseudorapidity correlations of oppositely charged particles were measured using the balance function method. The width of the balance function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions.

Published
2005

19. Electric charge fluctuations in centralPb+Pbcollisions at20A,30A,40A,80A, and158AGeV

Author

Branislav Sitar, Thorsten Sven Kollegger, Panagiota Foka, I. Szentpetery, Helena Bialkowska, D. Flierl, D. Panayotov, A. Wetzler, A. Rybicki, J. Zimányi, C. Meurer, Anton Dimitrov, I. Kraus, L. Betev, P. Seyboth, M. Makariev, A. Karev, C. Blume, Gunther Roland, F. Pühlhofer, N. Darmenov, R. Korus, M. Kliemant, G. Pálla, P. Christakoglou, Maciej Rybczyński, Lawrence Pinsky, Tatjana Susa, Kreso Kadija, Gyorgy Vesztergombi, V. Cerny, E. Kornas, Andreas Petridis, G. Georgopoulos, P. Freund, Christof Roland, C. Alt, Thomas A. Trainor, Andre Mischke, H. Sann, Apostolos Panagiotou, P. Csato, G. L. Melkumov, S. Kniege, St Mrówczyński, D. Barna, M. K. Mitrovski, A. Richard, R. Stock, M. Vassiliou, R. Bramm, M. van Leeuwen, Miroslav Pikna, Predrag Buncic, O. Chvala, M. Botje, I. K. Yoo, Katarzyna Grebieszkow, M. Behler, B. Baatar, Tome Anticic, J. Bartke, A. Sandoval, Rainer Arno Ernst Renfordt, V. Friese, M. Mateev, J. Sziklai, E. Skrzypczak, A. Billmeier, Ferenc Sikler, Christina Markert, V. Eckardt, H. Ströbele, P. Filip, J. Zaranek, Marek Kowalski, Bożena Boimska, Peter Levai, E. Gladysz, P. Dinkelaker, J. Gál, Leander Litov, C. Höhne, Jeffrey G. Reid, Gabor Istvan Veres, Zbigniew Wlodarczyk, Z. Fodor, J. Bracinik, Alexander Malakhov, Dezso Varga, Jozsef Molnar, Michal Kreps, S. Hegyi, Rene Brun, G. Stefanek, B. Lungwitz, N. Schmitz, V. I. Kolesnikov, D. Vranic, B. W. Mayes, J. G. Cramer, and Marek Gaździcki

Subjects
Quantum chromodynamics, Quark, Physics, Nuclear and High Energy Physics, Charge conservation, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, Electric charge, Gluon, Nuclear physics, Strange matter, Pion, Quark–gluon plasma, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Results are presented on event-by-event electric charge fluctuations in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV. The observed fluctuations are close to those expected for a gas of pions correlated by global charge conservation only. These fluctuations are considerably larger than those calculated for an ideal gas of deconfined quarks and gluons. The present measurements do not necessarily exclude reduced fluctuations from a quark-gluon plasma because these might be masked by contributions from resonance decays.

Published
2004

20. Energy and centrality dependence of deuteron and proton production inPb+Pbcollisions at relativistic energies

Author

R. Korus, P. Christakoglou, A. Wetzler, M. Behler, V. I. Kolesnikov, Apostolos Panagiotou, G. L. Melkumov, A. Sandoval, Thorsten Sven Kollegger, D. Vranic, Tatjana Susa, Gyorgy Vesztergombi, M. Vassiliou, G.E. Cooper, P. Freund, Marek Kowalski, Andreas Petridis, E. Gladysz, P. Dinkelaker, J. Sziklai, Andre Mischke, K. Perl, Tome Anticic, M. K. Mitrovski, Miroslav Pikna, M. van Leeuwen, C. Höhne, P. Filip, H. Sann, I. Kraus, Z. Fodor, Dezso Varga, N. Xu, Gunther Roland, M. Botje, Bożena Boimska, P. Seyboth, J. Bracinik, B. W. Mayes, Peter Levai, S. Hegyi, Rainer Arno Ernst Renfordt, Jozsef Molnar, St Mrówczyński, Michal Kreps, Kreso Kadija, Gabor Istvan Veres, D. Barna, J. G. Cramer, E. Skrzypczak, B. Baatar, G. Pálla, Christof Roland, W. Retyk, Marek Gaździcki, G. Stefanek, Ferenc Sikler, L. Betev, Rene Brun, I. K. Yoo, Helena Bialkowska, Alexander Malakhov, Thomas A. Trainor, O. Chvala, A. Rybicki, J. Gál, A. Billimeier, C. Blume, N. Schmitz, J. Zimányi, C. Meurer, H. G. Fischer, J. Bartke, Lawrence Pinsky, Christina Markert, J. Zaranek, Peter Martin Jacobs, R. Bramm, Szentpétery, Predrag Buncic, Jeffrey G. Reid, V. Eckardt, Zbigniew Wlodarczyk, A. Karev, Maciej Rybczyński, F. Pühlhofer, V. Cerny, V. Friese, G. Georgopoulos, Siegfried Wenig, H. Ströbele, P. Csato, R. Stock, Branislav Sitar, and Panagiota Foka

Subjects
Nuclear reaction, Physics, Coalescence (physics), Nuclear physics, Nuclear and High Energy Physics, Proton, Hadron, Transverse mass, Rapidity, Atomic physics, Nuclear Experiment, Nucleon, Charged particle
Abstract

The transverse mass mt distributions for deuterons and protons are measured in Pb + Pb reactions near midrapidity and in the range 0

Published
2004

21. Directed and elliptic flow of charged pions and protons inPb+Pbcollisions at40Aand158AGeV

Author

A. Wetzler, Thorsten Sven Kollegger, Lawrence Pinsky, Gyorgy Vesztergombi, M. Vassiliou, Phuong Mai Dinh, Tome Anticic, Michal Kreps, I. Kraus, P. Seyboth, A. Karev, Rainer Arno Ernst Renfordt, J. Y. Ollitrault, F. Pühlhofer, Jeffrey G. Reid, Andre Mischke, A. M. Poskanzer, V. Eckardt, Sergey Voloshin, Zbigniew Wlodarczyk, V. Cerny, Kreso Kadija, J. Zaranek, J. Gál, V. Friese, Gunther Roland, Helena Bialkowska, Marek Kowalski, Ferenc Sikler, G.E. Cooper, Tatjana Susa, Gergely Palla, Peter Martin Jacobs, Christof Roland, R. Bramm, Predrag Buncic, Thomas A. Trainor, St Mrówczyński, E. Gladysz, P. Dinkelaker, Andreas Petridis, L. Betev, P. Freund, G. Odyniec, Branislav Sitar, Panagiota Foka, K. Perl, M. van Leeuwen, Dezso Varga, M. K. Mitrovski, E. Skrzypczak, A. Rybicki, Nicolas Borghini, J. Zimányi, C. Meurer, O. Chvala, P. Csato, M. Botje, R. Stock, A. Billmeier, D. Barna, R. Korus, Christina Markert, Apostolos Panagiotou, C. Höhne, G. L. Melkumov, N. Schmitz, Jozsef Molnar, M. Rybczynśki, C. Alt, Miroslav Pikna, J. Sziklai, B. W. Mayes, V. I. Kolesnikov, D. Vranic, B. Baatar, J. G. Cramer, Marek Gaździcki, G. Stefanek, Christoph Blume, I. Szentpetery, S. Kniege, Rene Brun, Z. Fodor, J. Bracinik, Gabor Istvan Veres, G. Georgopoulos, S. Hegyi, R.J.M. Snellings, W. Retyk, H. Ströbele, M. Behler, H. Sann, A. Sandoval, P. Filip, I. K. Yoo, Alexander Malakhov, H. G. Ritter, Bożena Boimska, Peter Levai, and J. Bartke

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Pion, Flow (mathematics), Plane (geometry), Elliptic flow, Transverse momentum, Detector, Rapidity, Nuclear Experiment, Event (particle physics)
Abstract

Directed and elliptic flow measurements for charged pions and protons are reported as a function of transverse momentum, rapidity, and centrality for 40A and 158A GeV Pb+Pb collisions, as recorded by the NA49 detector. Both the standard method of correlating particles with an event plane and the cumulant method of studying multiparticle correlations are used. In the standard method the directed flow is corrected for conservation of momentum. In the cumulant method elliptic flow is reconstructed from genuine four-, six-, and eight-particle correlations, showing the first unequivocal evidence for collective motion in A+A collisions at SPS energies.

Published
2003

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