The onset of the anomalous J/psi suppression in Pb-Pb collisions at the CERN SPS

TL;DR

This paper investigates the onset of anomalous J/psi suppression in lead-lead collisions at CERN SPS, analyzing how suppression correlates with collision centrality and participant nucleons to understand quark-gluon plasma formation.

Contribution

It provides an analysis of J/psi suppression as a function of collision centrality and introduces a correlation study between participant nucleons and suppression patterns.

Findings

Suppression pattern shows a threshold behavior with centrality.

Correlation between Npart and EZDC supports a sudden suppression mechanism.

Results support the formation of quark-gluon plasma at specific collision conditions.

Abstract

The J/psi suppression observed by the NA50 experiment is one of the most striking signatures for quark gluon plasma formation in Pb-Pb collisions at 158 AGeV. The J/psi production has been studied as a function of the centrality of the collision estimated via the forward energy EZDC released in a zero degree calorimeter (ZDC). The study of the correlation between the number of participant nucleons in the collisions, Npart, and EZDC allows to check whether the J/psi suppression pattern vs. EZDC is compatible with a sudden J/psi suppression mechanism expressed as a function of Npart.