J/$ψ$ and $ψ$(2S) production in p-Pb collisions with ALICE at the LHC

Abstract

The ALICE collaboration has studied the inclusive J/$ψ$ and $ψ(\mathrm{2S})$ production in p-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV at the CERN LHC. The J/$ψ$ measurement is performed in the $μ^{+}μ^{-}$ ( - 4.46 < $y_{cms}$ < - 2.96 and 2.03 < $y_{cms}$ < 3.53 ) and in the $e^{+}e^{-}$ ( - 1.37 < $y_{cms}$ < 0.46 ) decay channels, down to zero transverse momentum. The results are in fair agreement with theoretical predictions based on nuclear shadowing, as well as with models including, in addition, a contribution from partonic energy loss. Finally, the $ψ(\mathrm{2S})$ measurement in the $μ^{+}μ^{-}$ decay channel has been performed. In particular, a significantly smaller $ψ(\mathrm{2S})$ nuclear modification factor, with respect to the J$/ψ$ one, has been observed.