Inclusive, prompt and non-prompt J/ψ production at mid-rapidity in Pb-Pb collisions at s N N = 2.76 $$ \sqrt{s_{\mathrm{NN}}}=2.76 $$ TeV

Abstract

The transverse momentum (p T ) dependence of the nuclear modification factor R AA and the centrality dependence of the average transverse momentum p T for inclusive J/ have been measured with ALICE for Pb-Pb collisions at s NN = 2.76 TeV in the e + e -decay channel at mid-rapidity (|y| < 0.8). The p T is significantly smaller than the one observed for pp collisions at the same centre-of-mass energy. Consistently, an increase of R AA is observed towards low p T . These observations might be indicative of a sizable contribution of charm quark coalescence to the J/ production. Additionally, the fraction of non-prompt J/ from beauty hadron decays, f B , has been determined in the region 1.5 < p T < 10 GeV/c in three centrality intervals. No significant centrality dependence of f B is observed. Finally, the R AA of non-prompt J/ is discussed and compared with model predictions. The nuclear modification in the region 4.5 < p T < 10 GeV/c is found to be stronger than predicted by most models.