J/ψ and ψ(2S) production in small systems with PHENIX

Abstract

The nuclear modification of J/ψ production has been studied at forward and backward rapidity in the collision systems p+Al, p+Au, and 3He+Au. A comparison of results for p+Au and 3He+Au is presented, with a focus on possible differences caused by the different particle multiplicity in the final state. The modification of ψ(2S) production in p+Au collisions has also been studied at forward and backward rapidity as a function of centrality. The ψ(2S) results complement earlier results at mid-rapidity at RHIC energies and results obtained at LHC energies, revealing a strong rapidity dependence of the ψ(2S) nuclear modification at RHIC energies that is indicative of final state effects.