Quarkonia Measurements by the CMS Experiment in pp and PbPb Collisions

TL;DR

This paper reports measurements of quarkonia production in proton-proton and lead-lead collisions using CMS, highlighting the first separation of prompt and non-prompt J/psi in heavy-ion collisions and quantifying suppression effects.

Contribution

It presents the first separation of prompt and non-prompt J/psi and excited Upsilon states in heavy-ion collisions, providing new insights into quarkonia suppression mechanisms.

Findings

Separation of prompt and non-prompt J/psi in heavy-ion collisions.

Quantification of suppression of various quarkonium states in PbPb collisions.

Comparison of quarkonia production between pp and PbPb collisions.

Abstract

Quarkonia have been studied in different collision system and energy in order to understand the effects of the hot and dense medium created in heavy-ion collisions. CMS is well suited to measure quarkonia decays to muons given the muon identification and charged particle tracking capability. We report here prompt, non-prompt J/\psi, and \Upsilon\ production measured by the CMS experiment in pp collisions at \sqrt{s}=7 TeV. In addition, the J/\psi\ and \Upsilon\ production in PbPb at \sqrt{s_{NN}}=2.76 TeV and pp collisions at the same per nucleon energy are measured and compared. Prompt and non-prompt J/\psi\ contributions are separated for the first time in heavy-ion collisions, as is the ground from the excited states in the \Upsilon\ family. Suppression in PbPb at \sqrt{s_{NN}}=2.76 TeV is quantified for prompt J/\psi, B->J/\psi, and \Upsilon(1S), as well as the relative suppression of \Upsilon(2S+3S) compared to \Upsilon(1S).