LHCb results from the proton-lead collisions

Abstract

The proton-lead (pPb) data taking during 2013 allows LHCb to expand its core physics program into the regime of heavy ion physics. Recent results of ψ(2S) mesons are shown, including the measurements of the nuclear modification factor and the forward-backward production ratio. The measurements are performed for prompt ψ(2S) mesons, originating from the pPb collision points, and ψ(2S) mesons from b-hadron decays. The results show that the suppression of prompt ψ(2S) mesons are much stronger than that of prompt J/ψ mesons. The results of ψ(2S) from b-hadron decays are consistent with those of J/ψ from b-hadron decays.