UC Davis

J / ψ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement of inclusive J / ψ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at s NN = 200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The J / ψ yields are measured in a wide transverse momentum ( p T ) range of 0.15 GeV/c to 12 GeV/c from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the J / ψ yield is suppressed by a factor of approximately 3 for p T > 5 GeV/c relative to that in p + p collisions scaled by the number of binary nucleon-nucleon collisions. The J / ψ nuclear modification factor displays little dependence on p T in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by J / ψ mesons in the QGP.