J/psi suppression in Pb-Pb collisions at CERN SPS

TL;DR

This paper reports on the observation of anomalous J/psi suppression in lead-lead collisions at CERN SPS, providing evidence for the formation of quark-gluon plasma in high-energy nuclear collisions.

Contribution

It presents experimental evidence of J/psi suppression in Pb-Pb collisions, supporting the hypothesis of quark-gluon plasma formation at CERN SPS.

Findings

J/psi suppression observed in central Pb-Pb collisions

Pattern consistent with quark-gluon plasma production

Supports phase transition from hadronic matter to QGP

Abstract

The NA38 and NA50 experiments at the CERN SPS have measured charmonium production in different colliding systems with the aim of observing a phase transition from ordinary hadronic matter towards a state in which quarks and gluons are deconfined (Quark Gluon Plasma, QGP). In fact it was predicted that the J/psi yield should be suppressed in deconfined matter. The analysis of the data collected by the NA50 experiment with Pb-Pb collisions at 158 GeV/c per nucleon shows that the J/psi is anomalously suppressed in central collisions and the observed pattern can be considered as a strong indication for QGP production.