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Lambda and Antilambda reconstruction in central Pb+Pb collisions using a time projection chamber
(1997)
Yates, Tim A. ; 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. ; Kowalski, Marek ; Lasiuk, Brian ; Lévai, Péter ; Malakhov, Aleksandr I. ; Margetis, Spyridon ; Markert, Christina ; Melkumov, Georgy L. ; Mock, Andreas ; Molnár, József ; Nelson, John M. ; Odyniec, Grazyna Janina ; 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 ; Zimányi, József ; Zhu, X Z ; Zybert, Ryszard
The large acceptance time projection chambers of the NA49 experiment are used to record the trajectory of charged particles from Pb + Pb collisions at 158 GeV per nucleon. Neutral strange hadrons have been reconstructed from their charged decay products. To obtain distributions of Λ, and Ks0 in discrete bins of rapidity, y, and transverse momentum, pT, calculations have been performed to determine the acceptance of the detector and the efficiency of the reconstruction software as a function of both variables. The lifetime distributions obtained give values of cτ = 7.8 ± 0.6 cm for Λ and cτ = 2.5 ± 0.3 cm for Ks0, consistent with data book values.
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.
Seyboth, Peter ; Alt, Christopher ; Antičić, Tome ; Baatar, B. ; Barna, Daniel ; Bartke, Jerzy ; Betev, Latchezar ; Białkowska, Helena ; Blume, Christoph ; Boimska, Bożena ; Botje, Michiel ; Bracinik, Juraj ; Bramm, Roland ; Brun, René ; Bunčić, Predrag ; Černý, 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 ; Hoehne, 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 Vasilev ; Malakhov, Aleksandr I. ; Markert, Christina ; Mateev, Matej D. ; Mayes, Bill W. ; Melkumov, Georgy L. ; Meurer, Christine ; Mischke, André ; Mitrovski, Michael Kosta ; Molnar, József ; Mrowczynski, Stanislaw ; Pálla, Gabriella ; Panagiotou, Apostolos D. ; Panayotov, Dobromir ; Petridis, Athanasios ; Pikna, Miroslav ; Pinsky, Lawrence ; Pühlhofer, Falk ; Renfordt, Rainer Arno Ernst ; Richard, Agnes Carol Joanna ; Roland, Christof ; Roland, Gunther ; Rybczyński, Maciej ; Rybicki, Andrzej ; Sandoval, Andres ; Sann, Hans ; Schmitz, Norbert ; Seyboth, Peter ; Sikler, Ferenc ; Sitar, Branislav ; Skrzypczak, Ewa ; Stefanek, Grzegorz ; Stock, Reinhard ; Ströbele, Herbert ; Šuša, Tatjana ; Szentpetery, 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 ; Zimanyi, József
Particle production in central Pb+Pb collisions was studied with the NA49 large acceptance spectrometer at the CERN SPS at beam energies of 20, 30, 40, 80, and 158 GeV per nucleon. A change of the energy dependence is observed around 30A GeV for the yields of pions and strange particles as well as for the shapes of the transverse mass spectra. At present only a reaction scenario with onset of deconfinement is able to reproduce the measurements.
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-Dziaduś, 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 Vasilev ; 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.
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-Dziaduś, 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 Vasilev ; 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.
Experimental and theoretical studies of fluctuations in nucleus-nucleus interactions at high energies have started to play a major role in understanding of the concept of strong interactions. The elaborated procedures have been developed to disentangle different processes happening during nucleus-nucleus collisions. The fluctuations caused by a variation of the number of nucleons which participated in a collision are frequently considered the unwanted one. The methods to reduce the impact of these fluctuations in fixed-target experiments are reviewed and tested. They can be of key importance in the following ongoing fixed-target heavy-ion experiments: NA61/SHINE at the CERN SPS, STAR-FXT at the BNL RHIC, BMN at JINR Nuclotron, HADES at the GSI SIS18 and in future experiments such as NA60+ at the CERN SPS, CBM at the FAIR SIS100, JHITS at J-PARC-HI MR.