Inclusive J/$\psi$ production at forward and backward rapidity in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV

International audienceInclusive J/ψ production is studied in p-Pb interactions at a centre-of-mass energy per nucleon-nucleon collision $ \sqrt{s_{\mathrm{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_{\mathrm{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