Open Access

Marco van Leeuwen, Sergey V. Afanasiev, Tome Antičić, B. Baatar, Daniel Barna, Jerzy Bartke, Robert Allan Barton, Matthias Behler, Latchezar Betev, Helena Białkowska, Anja Billmeier, Christoph Blume, Charles O. Blyth, Bożena Boimska, Michiel Botje, Juraj Bracinik, Roland Bramm, René Brun, Predrag Bunčić, Vladimír Černý, Ondrej Chvala, John G. Cramer, Péter Csató, Peter Dinkelaker, Volker Eckardt, Peter Filip, Hans Gerhard Fischer, Zoltán Fodor, Panagiota Foka, Peter Freund, Volker Friese, József Gál, Marek Gaździcki, George Georgopoulos, Ewa Gładysz, Sándor Hegyi, Claudia Höhne, George J. Igo, Peter Graham Jones, Krešo Kadija, Alexandre Karev, Vadim I. Kolesnikov, Thorsten Kollegger, Marek Kowalski, Ingrid Kraus, Michal Kreps, Marco van Leeuwen, Péter Lévai, Aleksandr I. Malakhov, Spyridon Margetis, Christina Markert, Bill W. Mayes, Georgy L. Melkumov, Christine Meurer, André Mischke, Michael Kosta Mitrovski, József Molnár, John M. Nelson, Gabriella Pálla, Apostolos D. Panagiotou, Katarzyna Perl, Athanasios Petridis, Miroslav Pikna, Lawrence Pinsky, Falk Pühlhofer, Jeffrey G. Reid, Rainer Arno Ernst Renfordt, Waldemar Retyk, Christof Roland, Gunther Roland, Andrzej Rybicki, Thomas Sammer, Andres Sandoval, Hans Sann, Norbert Schmitz, Peter Seyboth, Ferenc Siklér, Branislav Sitar, Ewa Skrzypczak, Gordon Thomas Anderson Squier, Reinhard Stock, Herbert Ströbele, Tatjana Šuša, Imre Szentpétery, János Sziklai, Thomas A. Trainor, Dezsö Varga, Maria Vassiliou, Gábor I. Veres, György Vesztergombi, Danilo Vranić, Siegfried Wenig, Alexander Albert Wetzler, Charles A. Whitten, In-Kwon Yoo, Jacek Zaranek, József Zimányi

• The energy dependence of hadron production in central Pb+Pb collisions is presented and discussed. In particular, midrapidity m_T-spectra for pi-, K-, K+, p, bar p, d, phi, Lambda and bar Lambda at 40, 80 and 158 AGeV are shown. In addition Xi and Omega spectra are available at 158 AGeV. The spectra allow to determine the thermal freeze-out temperature T and the transverse flow velocity beta_T at the three energies. We do not observe a significant energy dependence of these parameters; furthermore there is no indication of early thermal freeze-out of Xi and Omega at 158 AGeV. Rapidity spectra for pi-, K-, K+ and phi at 40, 80 and 158 AGeV are shown, as well as first results on Omega rapidity distributions at 158 AGeV. The chemical freeze-out parameters T and mu_B at the three energies are determined from the total yields. The parameters are close to the expected phase boundary in the SPS energy range and above. Using the total yields of kaons and lambdas, the energy dependence of the strangeness to pion ratio is discussed. A maximum in this ratio is found at 40 AGeV. This maximum could indicate the formation of deconfined matter at energies above 40 AGeV. A search for open charm in a large sample of 158 AGeV events is presented. No signal is observed. This result is compared to several model predictions.