ϒ Production in p+p, d+Au, Au+Au collisions at in STAR

Abstract

The properties of the quark-gluon Plasma (QGP) produced in heavy-ion collisions can be investigated by studying its effect on quarkonia production. Suppression of quarkonia is theorized to be a QGP signature due to the Debye color screening of the potential between the heavy quarks. In particular, the ϒ states are of interest because effects due to co-movers and feed down are smaller than for J/ψ. Lattice studies show that a sequential suppression of quarkonia states in heavy-ion collisions when compared to production in p+p collisions can provide us with a thermometer for the matter produced in relativistic heavy-ion collisions. This requires a detailed understanding of ϒ production in p+p collisions which gives a baseline needed to calculate RAA. It is also necessary to understand ϒ production in d+Au collisions in order to properly account for cold nuclear matter effects. We present our preliminary results for mid-rapidity ϒ production in p+p, d+Au and Au+Au at in the STAR experiment. We compare these results with models based on QCD calculations.