第十七届全国核物理大会

The production of heavy quarkonia has been extensively used to probe the Quark-Gluon Plasma (QGP) created in heavy ion collisions. The suppression of /$\psi$ in a deconfined medium due to Debye color screening of the charm quark potential has been proposed as a signature of the QGP formation. Interpretation of /$\psi$ suppression requires good understandings of its production mechanism in elementary collisions. Despite decades of efforts, the /$\psi$ production mechanism in p+p collisions is still not fully understood. /$\psi$ measurements in p+p collisions can provide additional insights into its production mechanism. We present the measurements of the production cross-sections of the J/$\psi$ meson as a function of transverse momentum, as well as its yield dependence on charged-particle multiplicity in proton-proton collisions at center-of-mass energies of 510 and 500 GeV using data recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC).