Quarkonium production in pp and heavy-ion collisions

TL;DR

This paper models bottomonium production in proton-proton and heavy-ion collisions using a formalism that accounts for quark-antiquark pairing, incorporating temperature-dependent wavefunctions and scattering effects, aligning well with experimental data.

Contribution

It introduces a novel application of Remler's formalism to describe bottomonium production, including temperature effects and scattering dynamics in heavy-ion collisions.

Findings

Results align with ALICE and CMS data.

Off-diagonal recombination of bottomonium is minimal.

Heavy quark interaction rate is suppressed to 10% in quark-gluon plasma.

Abstract

We describe bottomonium production not only in pp collisions but also in heavy-ion collisions by using the Remler's formalism where quarkonium density operator is applied to all possible combination of heavy quark and heavy antiquark pairs. In pp collisions heavy (anti)quark momentum is provided by the PYTHIA event generator after rescaling $p_T$ and rapidity to imitate the FONLL calculations. Then spatial separation between heavy quark and heavy antiquark is introduced based on the uncertainty principle. In heavy-ion collisions quarkonium wavefunction changes with temperature assuming heavy quark potential equals the free energy of heavy quark and heavy antiquark system in heat bath. The density operator is updated whenever heavy quark or heavy antiquark scatters in QGP produced in heavy-ion collisions. Our results are consistent with the experimental data from ALICE and CMS Collaborations assuming that the interaction rate of heavy (anti)quark in quarkonium is suppressed to 10 \% that of unbound heavy (anti)quark. We also find that off-diagonal recombination of bottomonium barely happens even in Pb+Pb collisions at $\sqrt{s}=5.02$ TeV.