| Article | |
| Report number | nucl-ex/0506002 |
| Title | e+e--pair production in Pb-Au collisions at 158 GeV per nucleon |
| Related title | GEV |
| Author(s) |
Agakichiev, G. (Darmstadt, GSI) ; Appelshauser, H. (Heidelberg U.) ; Bielcikova, J. (Heidelberg U. ; Heidelberg, Max Planck Inst.) ; Baur, R. (Heidelberg U.) ; Braun-Munzinger, P. (Darmstadt, GSI) ; Cherlin, A. (Weizmann Inst.) ; Damjanovic, S. (Heidelberg U.) ; Drees, A. (Stony Brook U.) ; Esumi, S. (Heidelberg U.) ; Faschingbauer, U. (Heidelberg, Max Planck Inst. ; Heidelberg U.) ; Fraenkel, Z. (Weizmann Inst.) ; Fuchs, Ch. (Heidelberg, Max Planck Inst.) ; Gatti, E. (Milan Polytechnic) ; Glassel, P. (Heidelberg U.) ; Hering, G. (Darmstadt, GSI) ; de los Heros, C.P. (Weizmann Inst.) ; Holl, P. (Brookhaven Natl. Lab.) ; Jung, Ch. (Heidelberg U.) ; Lenkeit, B. (Heidelberg U.) ; Marin, A. (Darmstadt, GSI) ; Messer, F. (Heidelberg U. ; Heidelberg, Max Planck Inst.) ; Messer, M. (Heidelberg U.) ; Miskowiec, D. (Darmstadt, GSI) ; Nix, O. (Heidelberg, Max Planck Inst.) ; Panebrattsev, Yu. (Dubna, JINR) ; Pfeiffer, A. (Heidelberg U.) ; Rak, J. (Heidelberg, Max Planck Inst.) ; Ravinovich, I. (Weizmann Inst.) ; Razin, S. (Dubna, JINR) ; Rehak, P. (Brookhaven Natl. Lab.) ; Richter, M. (Heidelberg U.) ; Sampietro, M. (Milan Polytechnic) ; Sako, H. (Darmstadt, GSI) ; Saveljic, N. (Heidelberg U.) ; Schmitz, W. (Heidelberg U.) ; Schukraft, J. (CERN) ; Seipp, W. (Heidelberg U.) ; Shimanskiy, S. (Dubna, JINR) ; Socol, E. (Weizmann Inst.) ; Specht, H.J. (Heidelberg U.) ; Stachel, J. (Heidelberg U.) ; Tel-Zur, G. (Weizmann Inst.) ; Tserruya, Itzhak (Weizmann Inst.) ; Ullrich, T. (Heidelberg U.) ; Voigt, C. (Heidelberg U.) ; Voloshin, S. (Heidelberg U.) ; Weber, C. (Heidelberg U.) ; Wessels, J.P. (Heidelberg U. ; Munster U.) ; Wienold, T. (Heidelberg U.) ; Wurm, J.P. (Heidelberg, Max Planck Inst.) ; Yurevich, V. (Dubna, JINR) |
| Publication | 2005 |
| Imprint | 1 Jun 2005 |
| Number of pages | 39 |
| In: | Eur. Phys. J. C 41 (2005) 475-513 |
| DOI | 10.1140/epjc/s2005-02272-3 |
| Subject category | Nuclear Physics |
| Abstract | We present the combined results on electron-pair production in 158 GeV/n {Pb-Au} ($\sqrt{s}$= 17.2 GeV) collisions taken at the CERN SPS in 1995 and 1996, and give a detailed account of the data analysis. The enhancement over the reference of neutral meson decays amounts to a factor of 2.31$\pm0.19 (stat.)\pm0.55 (syst.)\pm0.69 (decays)$ for semi-central collisions (28% $\sigma/\sigma_{geo}$) when yields are integrated over $m>$ 200 MeV/$c^2$ in invariant mass. The measured yield, its stronger-than-linear scaling with $N_{ch}$, and the dominance of low pair $p_t$ strongly suggest an interpretation as {\it thermal radiation} from pion annihilation in the hadronic fireball. The shape of the excess centring at $m\approx$ 500 MeV/$c^2$, however, cannot be described without strong medium modifications of the $\rho$ meson. The results are put into perspective by comparison to predictions from Brown-Rho scaling governed by chiral symmetry restoration, and from the spectral-function many-body treatment in which the approach to the phase boundary is less explicit. |
Corresponding record in: Inspire
Record created 2005-06-03, last modified 2024-05-08
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