J/ψ production at low pT in Au plus Au and Cu plus Cu collisions at √sNN=200 GeV with the STAR detector

The J/psi p(T) spectrum and nuclear modification factor (R-AA) are reported for p(T) < 5 GeV/c and vertical bar y vertical bar < 1 from 0% to 60% central Au + Au and Cu + Cu collisions at root s(NN) = 200 GeV at STAR. A significant suppression of p(T) - integrated J/psi production is observed in central Au + Au events. The Cu + Cu data are consistent with no suppression, although the precision is limited by the available statistics. R-AA in Au + Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with p(T). The data are compared to high-p(T) STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low p(T) are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration.