Υ production in p+p, d+Au, Au+Au collisions at = 200 GeV in STAR

Abstract

Quarkonia production can be used to investigate the properties of the dense matter produced in heavy-ion collisions at RHIC because the production is theorized to be suppressed due to the Debye color screening of the potential between the heavy quarks. Lattice calculations indicate that a sequential suppression of quarkonia states in heavy-ion collisions will give us a model dependent measurement of the temperature of the Quark Gluon Plasma (QGP). Suppression is determined by calculating RAA, which is the ratio of the production in p+p scaled by the number of binary collisions to the production in Au+Au. The Υ states are of particular interest because at 200 GeV the effects of recombination and co-mover absoprtion are smaller than for J / ψ, which lowers the systematic uncertainty of the interpretation of the RAA calculation. It is also important to consider cold nuclear effects, which can be determined from d+Au collisions. We will present our results for mid-rapidity Υ production in p+p, as well as our preliminary results in d+Au and Au+Au at = 200 GeV. These results will then be compared with theoretical QCD calculations.