Measurement of J/Ψ production in pp collisions at s√=7 TeV

Abstract

The production of J/ψ mesons in proton–proton collisions at s√=7\ensuremath TeV is studied with the LHCb detector at the LHC. The differential cross-section for prompt J/ψ production is measured as a function of the J/ψ transverse momentum pT and rapidity y in the fiducial region \ensuremathpT∈[0;14]\ensuremath GeV/c and y∈[2.0;4.5]. The differential cross-section and fraction of J/ψ from b-hadron decays are also measured in the same pT and y ranges. The analysis is based on a data sample corresponding to an integrated luminosity of 5.2 pb−1. The measured cross-sections integrated over the fiducial region are for prompt \ensuremathJ/ψ production and for J/ψ from b-hadron decays, where the first uncertainty is statistical and the second systematic. The prompt \ensuremathJ/ψ production cross-section is obtained assuming no J/ψ polarisation and the third error indicates the acceptance uncertainty due to this assumption.