Refine
Author
- Fodor, Zoltán (29) (remove)
Year of publication
Document Type
- Preprint (16)
- Article (12)
- Conference Proceeding (1)
Language
- English (29)
Has Fulltext
- yes (29)
Is part of the Bibliography
- no (29)
Keywords
- 900 GeV (1)
- ALICE (1)
- Charge fluctuations (1)
- Excluded volume (1)
- Hadron resonance gas (1)
- Imaginary chemical potential (1)
- LHC (1)
- PYTHIA (1)
- QCD equation of state (1)
- QGP (1)
Institute
Vovchenko, Volodymyr ; Steinheimer, Jan ; Philipsen, Owe ; Pásztor, Attila ; Fodor, Zoltán ; Katz, Sandor D. ; Stöcker, Horst
The QCD equation of state at finite baryon density is studied in the framework of a Cluster Expansion Model (CEM), which is based on the fugacity expansion of the net baryon density. The CEM uses the two leading Fourier coefficients, obtained from lattice simulations at imaginary μB, as the only model input and permits a closed analytic form. Excellent description of the available lattice data at both μB = 0 and at imaginary μB is obtained. We also demonstrate how the Fourier coefficients can be reconstructed from baryon number susceptibilities.
The first principle lattice QCD methods allow to calculate the thermodynamic observables at finite temperature and imaginary chemical potential. These can be compared to the predictions of various phenomenological models. We argue that Fourier coefficients with respect to imaginary baryochemical potential are sensitive to modeling of baryonic interactions. As a first application of this sensitivity, we consider the hadron resonance gas (HRG) model with repulsive baryonic interactions, which are modeled by means of the excluded volume correction. The Fourier coefficients of the imaginary part of the netbaryon density at imaginary baryochemical potential – corresponding to the fugacity or virial expansion at real chemical potential – are calculated within this model, and compared with the Nt = 12 lattice data. The lattice QCD behavior of the first four Fourier coefficients up to T 185 MeV is described fairly well by an interacting HRG with a single baryon–baryon eigenvolume interaction parameter b 1 fm3, while the available lattice data on the difference χB 2 − χB 4 of baryon number susceptibilities is reproduced up to T 175 MeV.
Seyboth, Peter ; Kniege, Stefan ; Antičić, Tome ; Barna, Daniel ; Bartke, Jerzy ; Barton, Robert Allan ; Betev, Latchezar ; Białkowska, Helena ; Billmeier, Anja ; Blume, Christoph ; Blyth, Charles O. ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Cerny, Vladimír ; Chvala, Ondrej ; Cramer, John G. ; Csató, Péter ; Dinkelaker, Peter ; Eckardt, Volker ; Filip, Peter ; Fischer, Hans Gerhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Gál, József ; Gaździcki, Marek ; Georgopoulos, George ; Gładysz-Dziaduś, Ewa ; Hegyi, Sándor ; Höhne, Claudia ; Jones, Peter Graham ; Kadija, Krešo ; Karev, Alexandre ; Kolesnikov, Vadim I. ; Kollegger, Thorsten ; Kowalski, Marek ; Kraus, Ingrid ; Kreps, Michal ; Leeuwen, Marco van ; Lévai, Péter ; Malakhov, Aleksandr I. ; Markert, Christina ; Mayes, Bill W. ; Melkumov, Georgy L. ; Mischke, André ; Molnár, József ; Nelson, John M. ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Perl, Katarzyna ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Retyk, Waldemar ; Roland, Christof ; Roland, Gunther ; Rybicki, Andrzej ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Siklér, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Squier, Gordon Thomas Anderson ; Stock, Reinhard ; Ströbele, Herbert ; Šuša, Tatjana ; Szentpétery, Imre ; Sziklai, János ; Trainor, Thomas A. ; Varga, Dezsö ; Vassiliou, Maria ; Veres, Gábor I. ; Vesztergombi, György ; Vranić, Danilo ; Wenig, Siegfried ; Wetzler, Alexander Albert ; Yoo, In-Kwon ; Zaranek, Jacek ; Zimányi, József
Experiment NA49 at the Cern SPS uses a large acceptance detector for a systematic study of particle yields and correlations in nucleus-nucleus, nucleon-nucleus and nucleon-nucleon collisions. Preliminary results for Pb+Pb collisions at 40, 80 and 158 A*GeV beam energy are shown and compared to measurements at lower and higher energies.
Rybczyński, Maciej ; Alt, Christopher ; Antičić, Tome ; Baatar, B. ; Barna, Daniel ; Bartke, Jerzy ; Betev, Latchezar ; Białkowska, Helena ; Billmeier, Anja ; Blume, Christoph ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Cerny, Vladimír ; Christakoglou, Panagiotis ; Chvala, Ondrej ; Cramer, John G. ; Csató, Péter ; Darmenov, Nikolay ; Dimitrov, Anton ; Dinkelaker, Peter ; Eckardt, Volker ; Farantatos, Gerassimos ; Flierl, Dominik Bernhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Gál, József ; Gaździcki, Marek ; Georgopoulos, George ; Gładysz-Dziaduś, Ewa ; Grebieszkow, Katarzyna ; Hegyi, Sándor ; Höhne, Claudia ; Kadija, Krešo ; Karev, Alexandre ; Kliemant, Michael ; Kniege, Stefan ; Kolesnikov, Vadim I. ; Kollegger, Thorsten ; Kornas, Ewelina ; Korus, Robert ; Kowalski, Marek ; Kraus, Ingrid ; Kreps, Michal ; Leeuwen, Marco van ; Lévai, Péter ; Litov, Leandr ; Lungwitz, Benjamin ; Makariev, Martin ; Malakhov, Aleksandr I. ; Markert, Christina ; Mateev, Matej D. ; Mayes, Bill W. ; Melkumov, Georgy L. ; Meurer, Christine ; Mischke, André ; Mitrovski, Michael Kosta ; Molnár, József ; Mrówczyński, Stanislaw ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Panayotov, Dobromir ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Richard, Agnes Carol Joanna ; Roland, Christof ; Roland, Gunther ; Rybicki, Andrzej ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Seyboth, Peter ; Siklér, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Stefanek, Grzegorz ; Stock, Reinhard ; Ströbele, Herbert ; Susa, Tatjana ; Szentpétery, Imre ; Sziklai, János ; Trainor, Thomas A. ; Trubnikov, Victor ; Varga, Dezsö ; Vassiliou, Maria ; Veres, Gábor I. ; Vesztergombi, György ; Vranić, Danilo ; Wetzler, Alexander Albert ; Włodarczyk, Zbigniew ; Yoo, In-Kwon ; Zaranek, Jacek ; Zimányi, József
System size dependence of multiplicity fluctuations of charged particles produced in nuclear collisions at 158 A GeV was studied in the NA49 CERN experiment. Results indicate a non-monotonic dependence of the scaled variance of the multiplicity distribution with a maximum for semi-peripheral Pb+Pb interactions with number of projectile participants of about 35. This effect is not observed in a string-hadronic model of nuclear collision HIJING.
Event-by-event fluctuations of particle ratios in central Pb + Pb collisions at 20 to 158 AGeV
(2004)
Roland, Christof ; Alt, Christopher ; Antičić, Tome ; Baatar, B. ; Barna, Daniel ; Bartke, Jerzy ; Betev, Latchezar ; Białkowska, Helena ; Billmeier, Anja ; Blume, Christoph ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Cerny, Vladimír ; Christakoglou, Panagiotis ; Chvala, Ondrej ; Cramer, John G. ; Csató, Péter ; Darmenov, Nikolay ; Dimitrov, Anton ; Dinkelaker, Peter ; Eckardt, Volker ; Farantatos, Gerassimos ; Flierl, Dominik Bernhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Gál, József ; Gaździcki, Marek ; Georgopoulos, George ; Gładysz, Ewa ; Grebieszkow, Katarzyna ; Hegyi, Sándor ; Höhne, Claudia ; Kadija, Krešo ; Karev, Alexandre ; Kliemant, Michael ; Kniege, Stefan ; Kolesnikov, Vadim I. ; Kollegger, Thorsten ; Kornaś, Ewelina ; Korus, Robert ; Kowalski, Marek ; Kraus, Ingrid ; Kreps, Michal ; Leeuwen, Marco van ; Lévai, Péter ; Litov, Leandr ; Lungwitz, Benjamin ; Makariev, Martin ; Malakhov, Aleksandr I. ; Markert, Christina ; Mateev, Matej D. ; Mayes, Bill W. ; Melkumov, Georgy L. ; Meurer, Christine ; Mischke, André ; Mitrovski, Michael Kosta ; Molnár, József ; Mrówczyński, Stanislaw ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Panayotov, Dobromir ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Roland, Gunther ; Richard, Agnes Carol Joanna ; Rybczyński, Maciej ; Rybicki, Andrzej ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Seyboth, Peter ; Siklér, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Stefanek, Grzegorz ; Stock, Reinhard ; Ströbele, Herbert ; Šuša, Tatjana ; Szentpétery, Imre ; Sziklai, János ; Trainor, Thomas A. ; Varga, Dezsö ; Vassiliou, Maria ; Veres, Gábor I. ; Vesztergombi, György ; Vranić, Danilo ; Wetzler, Alexander Albert ; Włodarczyk, Zbigniew ; Yoo, In-Kwon ; Zaranek, Jacek ; Zimányi, József
In the vicinity of the QCD phase transition, critical fluctuations have been predicted to lead to non-statistical fluctuations of particle ratios, depending on the nature of the phase transition. Recent results of the NA49 energy scan program show a sharp maximum of the ratio of K+ to Pi+ yields in central Pb+Pb collisions at beam energies of 20-30 AGeV. This observation has been interpreted as an indication of a phase transition at low SPS energies. We present first results on event-by-event fluctuations of the kaon to pion and proton to pion ratios at beam energies close to this maximum.
Pásztor, Attila ; Alba, Paolo ; Bellwied, Rene ; Borsányi, Szabolcs ; Fodor, Zoltán ; Günther, Jana N. ; Katz, Sándor ; Ratti, Claudia ; Mantovani Sarti, Valentina ; Noronha-Hostler, Jacquelyn ; Parotto, Paolo ; Portillo Vazquez, Israel ; Vovchenko, Volodymyr ; Stöcker, Horst
We use 4stout improved staggered lattice data at imaginary chemical potentials to calculate fugacity expansion coefficients in finite temperature QCD. We discuss the phenomenological interpretation of our results within the hadron resonance gas (HRG) model, and the hints they give us about the hadron spectrum. We also discuss features of the higher order coefficients that are not captured by the HRG. This conference contribution is based on our recent papers [1, 2].
Odyniec, Grazyna Janina ; Afanasiev, Sergey V. ; Alber, Thomas ; Appelshäuser, Harald ; Bächler, Joachim ; Bailey, Stephen John ; Barnby, Lee Stuart ; Bartke, Jerzy ; Białkowska, Helena ; Blyth, Charles O. ; Bock, Rudolf ; Bormann, Christian ; Brady, Franklin Paul ; Brockmann, Robert ; Buncic, Nenad ; Bunčić, Predrag ; Caines, Helen Louise ; Cebra, Daniel A. ; Chan, P. ; Cooper, Glenn E. ; Cramer, John G. ; Cramer, Pauline B. ; Csató, Péter ; Dietz, Oliver ; Dunn, Jason ; Eckardt, Volker ; Eckhardt, Frank ; Ferguson, M. I. ; Fischer, Hans Gerhard ; Flierl, Dominik Bernhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Fuchs, M. ; Gabler, Frank ; Gál, József ; Gaździcki, Marek ; Gładysz-Dziaduś, Ewa ; Grebieszkow, Jaroslaw ; Günther, Jörg ; Harris, John W. ; Hegyi, Sándor ; Henkel, Torsten ; Hill, L. A. ; Huang, Isaac ; Howe, Mark A. ; Hümmler, Holm Gero ; Igo, George J. ; Irmscher, Detlef ; Jacobs, Peter Martin ; Jones, Peter Graham ; Kadija, Krešo ; Kolesnikov, Vadim I. ; Konashenok, Anton ; Kowalski, Marek ; Lasiuk, Brian ; Lévai, Péter ; Malakhov, Aleksandr I. ; Margetis, Spyridon ; Markert, Christina ; Melkumov, Georgy L. ; Mock, Andreas ; Molnár, József ; Nelson, John M. ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Petridis, Athanasios ; Piper, Andreas ; Porter, R. Jefferson ; Poskanzer, Arthur M. ; Poziombka, Stefan ; Prindle, Duncan J. ; Pühlhofer, Falk ; Rauch, Wolfgang Hans ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Retyk, Waldemar ; Ritter, Hans Georg ; Röhrich, Dieter ; Roland, Christof ; Roland, Gunther ; Rudolph, Heinrich ; Rybicki, Andrzej ; Sakrejda, Iwona ; Sandoval, Andres ; Sann, Hans ; Semenov, Alexei Yu. ; Schäfer, Erich ; Schmischke, Dirk ; Schmitz, Norbert ; Schönfelder, Stefan ; Seyboth, Peter ; Seyerlein, Jürgen ; Siklér, Ferenc ; Skrzypczak, Ewa ; Squier, Gordon Thomas Anderson ; Stock, Reinhard ; Ströbele, Herbert ; Szentpétery, Imre ; Sziklai, János ; Toy, Milton Y. ; Trainor, Thomas A. ; Trentalange, Stephen ; Ullrich, Thomas ; Vassiliou, Maria ; Vesztergombi, György ; Vranić, Danilo ; Wang, Feipeng ; Weerasundara, Dhammika D. ; Wenig, Siegfried ; Whitten, Charles A. ; Wienold, Thomas ; Wood, Lindsay ; Yates, Tim A. ; Zimányi, József ; Zhu, Xue-Zhou ; Zybert, Ryszard
Using the NA49 main TPC, the central production of hyperons has been measured in CERN SPS Pb - Pb collisions at 158 GeV c-1. The preliminary ratio, studied at 2.0 < y < 2.6 and 1 < pT < 3 GeV c-1, equals ~ (13 ± 4)% (systematic error only). It is compatible, within errors, with the previously obtained ratios for central S + S [1], S + W [2], and S + Au [3] collisions. The fit to the transverse momentum distribution resulted in an inverse slope parameter T of 297 MeV. At this level of statistics we do not see any noticeable enhancement of hyperon production with the increased volume (and, possibly, degree of equilibration) of the system from S + S to Pb + Pb. This result is unexpected and counterintuitive, and should be further investigated. If confirmed, it will have a significant impact on our understanding of mechanisms leading to the enhanced strangeness production in heavy-ion collisions.
Mitrovski, Michael K. ; Alt, Christopher ; Antičić, Tome ; Baatar, B. ; Barna, Daniel ; Bartke, Jerzy ; Behler, Matthias ; Betev, Latchezar ; Białkowska, Helena ; Billmeier, Anja ; Blume, Christoph ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Cerny, Vladimír ; Christakoglou, Panagiotis ; Chvala, Ondrej ; Cramer, John G. ; Csató, Péter ; Darmenov, Nikolay ; Dimitrov, Anton ; Dinkelaker, Peter ; Eckardt, Volker ; Filip, Peter ; Fischer, Hans Gerhard ; Flierl, Dominik Bernhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Gál, József ; Gaździcki, Marek ; Georgopoulos, George ; Gładysz, Ewa ; Hegyi, Sándor ; Höhne, Claudia ; Kadija, Krešo ; Karev, Alexandre ; Kliemant, Michael ; Kniege, Stefan ; Kolesnikov, Vadim I. ; Kollegger, Thorsten ; Kornaś, Ewelina ; Korus, Robert ; Kowalski, Marek ; Kraus, Ingrid ; Kreps, Michal ; Leeuwen, Marco van ; Lévai, Péter ; Litov, Leandr ; Lungwitz, Benjamin ; Makariev, Martin ; Malakhov, Aleksandr I. ; Markert, Christina ; Mateev, Matej D. ; Mayes, Bill W. ; Melkumov, Georgy L. ; Meurer, Christine ; Mischke, André ; Mitrovski, Michael Kosta ; Molnár, József ; Mrówczyński, Stanislaw ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Panayotov, Dobromir ; Perl, Katarzyna ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Retyk, Waldemar ; Richard, Agnes Carol Joanna ; Roland, Christof ; Roland, Gunther ; Rybczyński, Maciej ; Rybicki, Andrzej ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Seyboth, Peter ; Siklér, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Stefanek, Grzegorz ; Stock, Reinhard ; Ströbele, Herbert ; Šuša, Tatjana ; Szentpétery, Imre ; Sziklai, János ; Trainor, Thomas A. ; Varga, Dezsö ; Vassiliou, Maria ; Veres, Gábor I. ; Vesztergombi, György ; Vranić, Danilo ; Wenig, Siegfried ; Wetzler, Alexander Albert ; Włodarczyk, Zbigniew ; Yoo, In-Kwon ; Zaranek, Jacek ; Zimányi, József
A non-monotonic energy dependence of the K + / pi + ratio with a sharp maximum close to 30 A GeV is observed in central Pb+Pb collisions. Within a statistical model of the early stage, this is interpreted as a sign of the phase transition to a QGP, which causes a sharp change in the energy dependence of the strangeness to entropy ratio. This observation naturally motivates us to study the production of multistrange hyperons (Xi, Omega) as a function of the beam energy. Furthermore it was suggested that the kinematic freeze-out of Omega takes place directly at QGP hadronization. If this is indeed the case, the transverse momentum spectra of the Omega directly reflect the transverse expansion velocity of a hadronizing QGP. In this report we show preliminary NA49 results on Omega - and Omega + production in central Pb+Pb collisions at 40 and 158 A GeV and compare them to measurements of Xi - and Xi + production in central Pb+Pb collisions at 30, 40, 80 and 158 A GeV.
Mischke, André ; Afanasiev, Sergey V. ; Antičić, Tome ; Baatar, B. ; Barna, Daniel ; Bartke, Jerzy ; Barton, Robert Allan ; Betev, Latchezar ; Białkowska, Helena ; Billmeier, Anja ; Blyth, Charles O. ; Blume, Christoph ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Cerny, Vladimír ; Chvala, Ondrej ; Cramer, John G. ; Csató, Péter ; Dinkelaker, Peter ; Eckardt, Volker ; Filip, Peter ; Flierl, Dominik Bernhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Gál, József ; Gaździcki, Marek ; Georgopoulos, George ; Gładysz-Dziaduś, Ewa ; Hegyi, Sándor ; Höhne, Claudia ; Igo, George J. ; Jones, Peter Graham ; Kadija, Krešo ; Karev, Alexandre ; Kolesnikov, Vadim I. ; Kollegger, Thorsten ; Kowalski, Marek ; Kraus, Ingrid ; Kreps, Michal ; Leeuwen, Marco van ; Lévai, Péter ; Malakhov, Aleksandr I. ; Margetis, Spyridon ; Markert, Christina ; Mayes, Bill W. ; Melkumov, Georgy L. ; Meurer, Christine ; Mitrovski, Michael Kosta ; Molnár, József ; Nelson, John M. ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Perl, Katarzyna ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Retyk, Waldemar ; Roland, Christof ; Roland, Gunther ; Rybicki, Andrzej ; Sammer, Thomas ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Seyboth, Peter ; Siklér, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Squier, Gordon Thomas Anderson ; Stock, Reinhard ; Ströbele, Herbert ; Šuša, Tatjana ; Szentpétery, Imre ; Sziklai, János ; Trainor, Thomas A. ; Varga, Dezsö ; Vassiliou, Maria ; Veres, Gábor I. ; Vesztergombi, György ; Vranić, Danilo ; Wenig, Siegfried ; Wetzler, Alexander Albert ; Whitten, Charles A. ; Yoo, In-Kwon ; Zaranek, Jacek ; Zimányi, József
Rapidity distributions for $\Lambda$ and $\bar{\Lambda}$ hyperons in central Pb-Pb collisions at 40, 80 and 158 A$\cdot$GeV and for ${\rm K}_{s}^{0}$ mesons at 158 A$\cdot$GeV are presented. The lambda multiplicities are studied as a function of collision energy together with AGS and RHIC measurements and compared to model predictions. A different energy dependence of the $\Lambda/\pi$ and $\bar{\Lambda}/\pi$ is observed. The $\bar{\Lambda}/\Lambda$ ratio shows a steep increase with collision energy. Evidence for a $\bar{\Lambda}/\bar{\rm p}$ ratio greater than 1 is found at 40 A$\cdot$GeV.
Mischke, André ; Afanasiev, Sergey V. ; Antičić, Tome ; Baatar, B. ; Barna, Daniel ; Bartke, Jerzy ; Barton, Robert Allan ; Behler, Matthias ; Betev, Latchezar ; Białkowska, Helena ; Billmeier, Anja ; Blume, Christoph ; Blyth, Charles O. ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Cerny, Vladimír ; Chvala, Ondrej ; Cramer, John G. ; Csató, Péter ; Dinkelaker, Peter ; Eckardt, Volker ; Filip, Peter ; Fischer, Hans Gerhard ; Fodor, Zoltán ; Foka, Panagiota ; Freund, Peter ; Friese, Volker ; Gál, József ; Gaździcki, Marek ; Georgopoulos, George ; Gładysz-Dziaduś, Ewa ; Hegyi, Sándor ; Höhne, Claudia ; Igo, George J. ; Jones, Peter Graham ; Kadija, Krešo ; Karev, Alexandre ; Kolesnikov, Vadim I. ; Kollegger, Thorsten ; Kowalski, Marek ; Kraus, Ingrid ; Kreps, Michal ; Leeuwen, Marco van ; Lévai, Péter ; Malakhov, Aleksandr I. ; Margetis, Spyridon ; Markert, Christina ; Mayes, Bill W. ; Melkumov, Georgy L. ; Meurer, Christine ; Mischke, André ; Mitrovski, Michael Kosta ; Molnár, József ; Nelson, John M. ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Perl, Katarzyna ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Reid, Jeffrey G. ; Renfordt, Rainer Arno Ernst ; Retyk, Waldemar ; Roland, Christof ; Roland, Gunther ; Rybicki, Andrzej ; Sammer, Thomas ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Seyboth, Peter ; Siklér, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Squier, Gordon Thomas Anderson ; Stock, Reinhard ; Ströbele, Herbert ; Šuša, Tatjana ; Szentpétery, Imre ; Sziklai, János ; Trainor, Thomas A. ; Varga, Dezsö ; Vassiliou, Maria ; Veres, Gábor I. ; Vesztergombi, György ; Vranić, Danilo ; Wenig, Siegfried ; Wetzler, Alexander Albert ; Whitten, Charles A. ; Yoo, In-Kwon ; Zaranek, Jacek ; Zimányi, József
Rapidity distributions for Lambda and anti-Lambda hyperons in central Pb-Pb collisions at 40, 80 and 158 AGeV and for K 0 s mesons at 158 AGeV are presented. The lambda multiplicities are studied as a function of collision energy together with AGS and RHIC measurements and compared to model predictions. A different energy dependence of the Lambda/pi and anti-Lambda/pi is observed. The anti-Lambda/Lambda ratio shows a steep increase with collision energy. Evidence for a anti-Lambda/anti-p ratio greater than 1 is found at 40 AGeV.