J/$\psi$ measurements in the STAR experiment

TL;DR

This paper reports on recent measurements of J/ψ production and suppression in heavy-ion collisions at various energies, providing insights into quark-gluon plasma properties and comparing results with theoretical models.

Contribution

It presents new experimental data on J/ψ nuclear modification factors, elliptic flow, and ψ(2S) to J/ψ ratios across different collision systems and energies.

Findings

J/ψ R_AA varies with collision energy and system

J/ψ elliptic flow observed at 200 GeV in Au+Au collisions

First measurement of ψ(2S) to J/ψ ratio in p+p at 500 GeV

Abstract

In this paper, we present recent STAR J/$\psi$ results. J/$\psi$ nuclear modification factors ($R_{AA}$) in Au+Au collisions at $\sqrt{s_{NN}} =$ 200, 62.4 and 39 GeV and in U+U collisions at $\sqrt{s_{NN}} =$ 193 GeV are measured and compared to different theoretical calculations. We also report J/$\psi$ elliptic flow ($v_{2}$) results in Au+Au collisions at $\sqrt{s_{NN}} =$ 200 GeV and the first $\psi(2S)$ to J/$\psi$ ratio measurement in $p+p$ collisions at $\sqrt{s} =$ 500 GeV.