Measurement of J/ψ production in p + p collisions at s=500 GeV at STAR experiment

Quarkonium measurements in heavy-ion collisions play an essential role in understanding the hot, dense medium created in such collisions. As a reference, their production mechanism in p + p collisions needs to be thoroughly understood. In this paper, we report the measurement of inclusive cross section of J/ψ with transverse momentum (pT) above 4 GeV/c at mid-rapidity in p + p collisions at s=500 GeV by the STAR experiment. The ratio of the yield of ψ(2S) to J/ψ integrated over 4