J/$\psi$ production measurements by the PHENIX experiment at RHIC

TL;DR

This paper reviews J/ψ production measurements at RHIC across various collision systems, revealing suppression patterns that suggest additional effects beyond cold nuclear matter, with potential insights from elliptic flow measurements.

Contribution

It provides new experimental data on J/ψ suppression and discusses the role of regeneration and elliptic flow in understanding quark-gluon plasma effects.

Findings

Suppression beyond cold nuclear matter effects in central Au+Au collisions

Less suppression at mid rapidity compared to forward rapidity

Potential indication of regeneration through elliptic flow measurements

Abstract

Measurements of J/$\psi$ production by the PHENIX experiment in p+p, d+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV are reviewed. The results show a suppression beyond what can be explained by cold nuclear matter effects in the most central Au+Au and to a lesser extent in Cu+Cu collisions. In addition, the suppression observed at mid rapidity in Au+Au is smaller than at forward rapidity, a tendency opposite to what is expected from the higher energy density at mid rapidity. Regeneration, a possible explanation, can be tested by measuring the elliptic flow parameter v$_2$ of J/$\psi$.