Speaker
Description
J/$\psi$ is an important probe to the properties of the quark-gluon plasma (QGP) created in heavy-ion collisions. Measurements from SPS, RHIC, and the LHC experiments show that J/$\psi$ production in heavy-ion collisions is an interplay of several effects, including dissociation and regeneration in QGP and cold nuclear matter effects. Studying the properties of the QGP via J/$\psi$ requires a good understanding of all these effects which is very challenging and requires high precision. In 2018, STAR collected a large sample of isobaric collisions ($^{96}_{44}Ru$ + $^{96}_{44}Ru$ and $^{96}_{40}Zr$ + $^{96}_{40}Zr$) at $\sqrt{s_\mathrm{NN}}$ = 200 GeV. The total number of good minimum bias triggered events is around 4 billion. This dataset provides a unique opportunity to perform centrality and transverse momentum ($p_T$) differential measurements of J/$\psi$ yields with good precision and in fine bins.
In this contribution, precision measurements of inclusive $J/\psi$ production in isobaric collisions at $\sqrt{s_\mathrm{NN}}$ = 200 GeV via the $e^{+}e^{-}$ decay channel will be presented. The centrality and $p_{T}$ dependences of the nuclear modification factor $R_\mathrm{AA}$ and $\left\langle p_{\rm{T}} \right\rangle$ as a function of centrality will be shown. The first measurement of the ratio of $\psi(2S)$ yield over that of J/$\psi$ in heavy-ion collisions at RHIC will also be presented.
