# Quark Matter 2012

12-18 August 2012
US/Eastern timezone

## J/$\psi$ production in $\sqrt{s_{NN}}$ = 39 GeV and 62.4 GeV Au+Au collisions from STAR

16 Aug 2012, 16:00
2h

Poster Heavy flavor and quarkonium production

Wangmei Zha (U)

### Description

The Relativistic Heavy Ion Collider (RHIC) is built to search for the Quark-gluon Plasma (QGP) and to study its properties in laboratory through high energy heavy-ion collisions. J/$\psi$ suppression in heavy-ion collisions due to color screening of quark and anti-quark has been proposed as a signature of QGP formation. But other mechanisms are likely to contribute to the observed J/$\psi$ in heavy-ion collisions such as the cold nuclear matter effect, charm quark recombination, sequential suppression, and hot wind dissociation. Measurements of J/$\psi$ invariant yields at different collision energies and centralities can shed new light on understanding the interplay of these mechanisms for J/$\psi$ production and medium properties. In this presentation we will report the measurements of J/$\psi$ invariant yields as a function of transverse momentum (with $p_{T}$ coverage: 0-5 GeV/c at mid-rapidity) in Au+Au collisions at $\sqrt{s_{NN}}$ = 39 GeV and 62.4 GeV taken in 2010 from STAR with full Time-of-Flight detector and Barrel ElectroMagnetic Calorimeter detector in operation. Centrality dependence of J/$\psi$ production and nuclear modification factors will be presented. Comparisons among different collision energies and model calculations will be discussed.

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