CERN Heavy Ion Forum

The Parton to Hadron Phase Transformation observed at the CERN SPS

by R. Stock (University of Frankfurt)

Europe/Zurich
CERN

CERN

Description
The most recent issue of NA50 J/Psi production data (at the QM Torino) exhibit an almost complete disappearance at the most central Pb+Pb collision samples. Taking (tentatively) this for final evidence of a QCD partonic suppression mechanism in the high-density phase we conclude that the system has to rehadronize upon expansion. In fact the comprehensive set of 4pi bulk hadron production rates and ratios that is becoming available offers a clear-cut fingerprint of the hadronization transition. A particularly important detail of this picture is seen in the question of whether totals strangeness production relative to non-strange holds a key to further elucidate the flavour composition of the partonic phase. Also the mechanisms by which the 'limiting hadronic temperature' is reached at the SPS but not reached at the AGS deserves attention, in order to arrive at a comprehensive and exhaustive analysis of the data.