Speaker
Description
We present the recent results of J/$\psi$-jet correlation and the cross-sections Y(nS) states in heavy-ion collisions, using the data collected by the CMS experiment at $\sqrt{s_{\rm{NN}}}=5.02$~TeV.
J/$\psi$ production has long been known to be modified in heavy-ion collisions, via, among many, the Debye screening effect. Indirect evidence of, in particular, the non-vanishing $v_{2}$ of J/$\psi$ at large transverse momentum, however, suggests that jet quenching may also play an important role in J/$\psi$ suppression. We present the final results of reconstructed J/$\psi$-jets in heavy-ion collisions. We measure the jet fragmentation function of jets containing a J/$\psi$ meson, to study the dependence of quenching effects on the degree of associated hadro-production inside the jet.
We also present the production cross-sections of Y(1S), Y(2S), and Y(3S) states pPb collision, and their nuclear modification factors (RpPb). The result shows that Y states are suppressed in pPb collision compared to pp collision, while less pronounced than it is in the lead-lead collision. Sequential ordering of the Y RpPb, with Y(1S) least suppressed and Y(3S) most suppressed, indicates the final-state modification of Y states in pPb collisions. Predictions using the final-state comover interaction model, which incorporates sequential suppression of bottomonia in pPb collisions, are in better agreement with the measured RpPb versus rapidity than predictions using initial-state modification models.
