Collisional and thermal dissociation of $J/\psi$ and ${\rm Y}$ states at the LHC

Abstract

We present new results for the suppression of high transverse momentum charmonium [$J/\psi ,\psi (2S)$] and bottomonium [${\rm Y}(1S),{\rm Y}(2S),{\rm Y}(3S)$] states in Pb+Pb collisions at the Large Hadron Collider. Our theoretical formalism combines the collisional dissociation of quarkonia, as they propagate in the quark-gluon plasma, with the thermal wavefunction effects due to the screening of the $Q\bar{Q}$ attractive potential in the medium. We find that a good description of the relative suppression of the ground and higher excited quarkonium states, transverse momentum and centrality distributions is achieved, when comparison to measurements at a center-of-mass energy of 2.76 TeV is performed. Theoretical predictions for the highest Pb+Pb center-of-mass energy of 5.02 TeV at the LHC, where new experimental results are being finalized, are also presented.

Comments: 8 pages, 8 eps figures; 2 figures and references added, introduction restructured; version to appear in PLB