J/ψ azimuthal anisotropy in Au+Au collisions at

Abstract

The study of J/ψ azimuthal anisotropy allows for a disentanglement of various production mechanisms and possibly an access to charm quark azimuthal anisotropy. J/ψ meson produced from direct pQCD processes have little azimuthal anisotropy due to the lack of collectivity or azimuthal preference of initial emitting, while J/ψ meson produced from recombination of charm quarks in the medium are expected to inherit the azimuthal anisotropy of the constituent charm quarks. We present measurements of J/ψ azimuthal anisotropy, with J/ψ reconstructed via the di-electron channel, as a function of transverse momentum in Au+Au collisions at . This analysis is carried out with data taken by the STAR experiment during RHIC operation in year 2011. Combined with the published results using 2010 data, the updated results provide further support to the conclusion that J/ψ production above 2 GeV/c is unlikely to be dominated by regeneration of fully thermalized charm quarks.