Speaker
Description
Charmonium is an important to probe the properties of the quark-gluon plasma (QGP) created in heavy-ion collisions due to the modification of its yield by the effects of dissociation and regeneration in QGP. About 2 billion events each in isobaric collisions ($^{96}_{44}Ru$ + $^{96}_{44}Ru$ and $^{96}_{40}Zr$ + $^{96}_{40}Zr$) at $\sqrt{s_\mathrm{NN}}$ = 200 GeV has been collected by STAR in 2018, providing a unique opportunity for the study of charmonium with observables has never been explored at RHIC before.
In this contribution, the J/$\psi$ are reconstructed via the $e^{+}e^{-}$ decay channel, and a machine learning technique is used when obtaining the $\psi(2\rm{S})$ signals. The first measurement of $\psi(2\rm{S})$ production in heavy ion collisions at RHIC will be presented. Centrality and transverse momentum dependence of J/$\psi$ nuclear modification factor and the ratio of $\psi(2\rm{S})$ yield over that of J/$\psi$ will be shown and physics implication will be discussed.
