Production of J/ψ and ϒ mesons in proton–lead collisions at sNN=5.02 TeV

Abstract

Abstract The production of J / ψ and ϒ-mesons decaying into the dimuon final state is studied at the LHCb experiment, covering the rapidity intervals 1.5 y 4.0 and − 5.0 y − 2.5 and transverse momentum p T 15 GeV / c , in proton–lead collisions at a proton–nucleon centre-of-mass energy of s N N = 5.02 TeV . The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb − 1 . The nuclear modification factor and the forward–backward production ratio are determined for J / ψ and ϒ ( 1 S ) mesons. At large rapidity a clear suppression of prompt J / ψ production is observed with respect to the production in pp collisions, while the suppression of J / ψ from b-hadron decays is less pronounced. The nuclear modification factor for ϒ ( 1 S ) mesons in the forward region is found to be similar to the one for J / ψ from b-hadron decays.