Inclusive J/ψ production at forward and backward rapidity in p-Pb collisions at $\sqrt{{s}_{NN}}=8.16$ TeV

Inclusive J/ψ production is studied in p-Pb interactions at a centre-of-mass energy per nucleon-nucleon collision $\sqrt{{s}_{NN}}=8.16$ TeV, using the ALICE detector at the CERN LHC. The J/ψ meson is reconstructed, via its decay to a muon pair, in the centre-of-mass rapidity intervals 2.03 < y cms < 3.53 and −4.46 < y cms < −2.96, where positive and negative y cms refer to the p-going and Pb-going direction, respectively. The transverse momentum coverage is p T < 20 GeV/c. In this paper, y cms- and p T-differential cross sections for inclusive J/ψ production are presented, and the corresponding nuclear modification factors R pPb are shown. Forward results show a suppression of the J/ψ yield with respect to pp collisions, concentrated in the region p T ≲ 5 GeV/c. At backward rapidity no significant suppression is observed. The results are compared to previous measurements by ALICE in p-Pb collisions at $\sqrt{{s}_{NN}}=5.02$ TeV and to theoretical calculations. Finally, the ratios R FB between forward- and backward-y cms R pPb values are shown and discussed.