New results on Initial State and Quarkonia with ALICE

TL;DR

This paper reviews ALICE experiment results on quarkonium production in p-Pb collisions at LHC energies, providing insights into initial-state effects and disentangling cold from hot nuclear matter influences on quarkonium yields.

Contribution

It presents new measurements of quarkonium production in p-Pb collisions at different energies, enhancing understanding of initial-state effects in heavy-ion collisions.

Findings

ALICE measured quarkonium yields at different rapidities and energies.

Results help distinguish cold nuclear matter effects from quark-gluon plasma effects.

Data contribute to modeling quarkonium production mechanisms.

Abstract

The study of quarkonia in heavy-ion collisions has been the subject of intense experimental and theoretical effort, ever since their production was predicted to be sensitive to the formation of a deconfined state of strongly-interacting matter, known as the Quark-Gluon Plasma (QGP). In p-Pb collisions, Cold Nuclear Matter (CNM) effects, such as nuclear shadowing or partonic energy loss, are expected to influence quarkonium production. The study of such system is therefore crucial to shed light on the mechanisms taking place at the initial-state of quarkonium production, and to disentangle the cold and hot nuclear effects envisioned in Pb-Pb collisions. The ALICE experiment at the LHC, is capable of reconstructing J/$\psi$, $\psi$(2S) and $\Upsilon$ states at forward rapidity through their $\mu^{\rm{+}}\mu^{\rm{-}}$ decay channel, as well as J/$\psi$ at central rapidity through their $e^{\rm{+}}e^{\rm{-}}$ decay channel, down to zero transverse momentum. A review of the main ALICE findings from the measurements of the inclusive quarkonium yields in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, collected during the LHC Run I period, as well as more recent results from J/$\psi$ measurements in p-Pb at $\sqrt{s_{\rm{NN}}}$ = 8.16 TeV, from LHC Run II period, will be presented in this paper.