Speaker
Wangmei Zha
(USTC/BNL)
Description
$J/\psi$ suppression in heavy-ion collisions due to color screening of quark and antiquark potential in the deconfined medium has been proposed as a signature of the QGP formation. Other mechanisms, such as the cold nuclear matter effect and charm quark recombination, are likely to contribute to the observed modification of $J/\psi$ production in heavy-ion collisions. Measurements of $J/\psi$ invariant yields in different collision energies, collision systems, and centralities can shed new light on the interplay of these mechanisms for $J/\psi$ production and medium properties.
In this presentation we report on new measurements of $J/\psi$ production at midrapidity ($|y| < 1.0$) from the Beam Energy Scan program (Au$+$Au collisions at $\sqrt{s_{NN}} =$ 39 GeV and 62.4 GeV) and U$+$U collisions at $\sqrt{s_{NN}}$ = 193 GeV at STAR. Centrality and transverse momentum dependence of $J/\psi$ invariant yields and the nuclear modification factor ($R_{AA}$) will be presented and compared to those for Au$+$Au collisions at $\sqrt{s_{NN}} =$ 200 GeV and to model calculations. The energy dependence of $J/\psi$ suppression will be discussed.
| On behalf of collaboration: | STAR |
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Primary author
Wangmei Zha
(USTC/BNL)
