We present the analysis of $\Upsilon\to e^{ +}e^{ -}$ production in d+Au collisions at $\sqrt{ s_{ NN}} = 200$ GeV from the STAR experiment. Using higher level dedicated $\Upsilon$ triggers, STAR has sampled 32 nb$^{ -1}$ of integrated luminosity in year 2008 d+Au run. The cross section is found as $BR\times{ ({ { d\sigma}\over{ dy}})}_{ y=0}^{ \Upsilon(1S+2S+3S)}=35\pm4(stat.)\pm5(sys.)$ nb and it is consistent with NLO CEM prediction with anti-shadowing effects. In addition we calculated the nuclear modification factor $R_{ dAu}=0.98\pm0.32(stat.)\pm0.28(sys.)$, which suggests the $\Upsilon(1S+2S+3S)$ production follows $N_{ bin}$ scaling.
Categories: nucl-ex hep-ex