2020 Impact factor 4.590
Particles and Fields
Eur. Phys. J. C 29, 79-85 (2003)
DOI: 10.1140/epjc/s2003-01209

On energy densities reached in heavy-ion collisions at the CERN SPS

J. Pisút1, 2, N. Pisútová2 and B. Tomásik1

1  CERN, Theory Division, 1211 Geneva 23, Switzerland
2  Department of Physics, Comenius University, 84248 Bratislava, Slovakia

(Received: 3 February 2003 / Revised version: 5 March 2003 / Published online: 5 May 2003 )

We present a few estimates of energy densities reached in heavy-ion collisions at the CERN SPS. The estimates are based on data and models of proton-nucleus and nucleus-nucleus interactions. In all of these estimates the maximum energy density in central Pb+Pb interactions is larger than the critical energy density $\varepsilon_c\approx 0.7\,\mbox{GeV/fm}^{3}$ following from lattice gauge theory computations. In estimates which we consider as realistic the maximum energy density is about $2\varepsilon_c$. In this way our analysis gives some support to claims that deconfined matter has been produced at the CERN SPS. Any definite statement requires a deeper understanding of formation times of partons and hadrons in nuclear collisions. We also compare our results with implicit energy estimates contained in earlier models of anomalous $J/\psi$ suppression in nuclear collisions.

© Società Italiana di Fisica, Springer-Verlag 2003