Περίληψη:
The energy dependence of hadron production ill central Pb+Pb collisions is presented and discussed. In particular, midrapidity mT-spectra for π-, K-, K+, p, p̄, d, φ, Λ and Λ̄ at 40, 80 and 158 AGeV are shown. In addition and Ω spectra are available at 158 AGeV. The spectra allow to determine the thermal freeze-out temperature T and the transverse flow velocity βT 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 and Ω at 158 AGeV. Rapidity spectra for π-, K-, K+ and φ at 40, 80 and 158 AGeV are shown, as well as first results on Ω rapidity distributions at 158 AGeV. The chemical freeze-out parameters T and μB 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. © 2003 Elsevier Science B.V. All rights reserved.
Συγγραφείς:
Van Leeuwen, M.
Afanasiev, S.V.
Anticic, T.
Baatar, B.
Barna, D.
Bartke, J.
Barton, R.A.
Behler, M.
Betev, L.
Białkowska, H.
Billmeier, A.
Blume, C.
Blyth, C.O.
Boimska, B.
Botje, M.
Bracinik, J.
Bramm, R.
Brun, R.
Bunčić, P.
Cerny, V.
Chvala, O.
Cramer, J.G.
Csató, P.
Dinkelaker, P.
Eckardt, V.
Filip, P.
Fischer, H.G.
Fodor, Z.
Foka, P.
Freund, P.
Friese, V.
Gál, J.
Gaździcki, M.
Georgopoulos, G.
Gladysz, E.
Hegyi, S.
Höhne, C.
Igo, G.
Jones, P.G.
Kadija, K.
Karev, A.
Kolesnikov, V.I.
Kollegger, T.
Kowalski, M.
Kraus, I.
Kreps, M.
Lévai, P.
Malakhov, A.I.
Margetis, S.
Markert, C.
Mayes, B.W.
Melkumov, G.L.
Meurer, C.
Mischke, A.
Mitrovski, M.
Molnár, J.
Nelson, J.M.
Pálla, G.
Panagiotou, A.D.
Perl, K.
Petridis, A.
Pikna, M.
Pinsky, L.
Pühlhofer, F.
Reid, J.G.
Renfordt, R.
Retyk, W.
Roland, C.
Roland, G.
Rybicki, A.
Sammer, T.
Sandoval, A.
Sann, H.
Schmitz, N.
Seyboth, P.
Siklér, F.
Sitar, B.
Skrzypczak, E.
Squier, G.T.A.
Stock, R.
Ströbele, H.
Susa, T.
Szentpétery, I.
Sziklai, J.
Trainor, T.A.
Varga, D.
Vassiliou, M.
Veres, G.I.
Vesztergombi, G.
Vranić, D.
Wenig, S.
Wetzler, A.
Whitten, C.
Yoo, I.K.
Zaranek, J.
Zimányi, J.
