Heavy-flavor production in CMS

The compact muon solenoid (CMS) detector at the large hadron collider (LHC) is ideal to measure the heavy flavor production, especially, in the dimuon channels in high-multiplicity environment. Compared to the $pp$ data scaled by the number of binary collisions, the yields of prompt and non-prompt $J/\psi$ and $\Upsilon$(1$S$) in PbPb collisions are strongly suppressed at $\sqrt{s_{NN}}$ = 2.76 TeV. In addition, the excited $\Upsilon$(2$S$+3$S$) states are also suppressed relative to the ground $\Upsilon$(1$S$) state in PbPb collisions. These results consistently indicate a significant medium effect on the heavy-flavor production in heavy-ion collisions at LHC.