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Measurement of ψ(2S) nuclear modification at backward and forward rapidity in p+p, p+Al, and p+Au collisions at sqrt(s_NN)=200 GeV

Suppression of the J/ψ nuclear-modification factor has been seen as a trademark signature of final- state effects in large collision systems for decades. In small systems, the nuclear modification was attributed to cold-nuclear-matter effects until the observation of strong differential suppression of the ψ(2S) state in p/d+A collisions suggested the presence of final- state effects. Results of J/ψ and ψ(2S) measurements in the dimuon decay channel are presented here for p+p, p+Al, and p+Au collision systems at sNN−−−√=200 GeV. The results are predominantly shown in the form of the nuclear- modification factor, RpA, the ratio of the ψ(2S) invariant yield per nucleon-nucleon collision in collisions of proton on target nucleus to that in p+p collisions. Measurements of the J/ψ and ψ(2S) nuclear-modification factor are compared with shadowing and transport-model predictions, as well as to complementary measurements at Large-Hadron- Collider energies.

Psi(2S), 200 GeV, PHENIX, RHIC

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