Quarkonium measurements at forward rapidity with ALICE at the LHC

TL;DR

This paper reviews ALICE's measurements of quarkonium production at forward rapidity across different collision systems and energies at the LHC, providing insights into QGP and Cold Nuclear Matter effects.

Contribution

It compiles and analyzes quarkonium measurements from ALICE at forward rapidity in various collision systems and energies, enhancing understanding of QGP and CNM effects.

Findings

Quarkonium suppression patterns observed in Pb--Pb collisions.

CNM effects characterized in p--Pb collisions.

Baseline measurements established in proton-proton collisions.

Abstract

Heavy quarks are produced at the first instant of a nucleus--nucleus collision and therefore are an important tool to study the subsequent high energy-density medium formed in ultra-relativistic heavy-ion collisions. A series of experimental efforts for understanding the properties of the Quark--Gluon Plasma (QGP), a medium consisting of a deconfined state of quarks and gluons, are based on measuring the bound states of heavy quark--anti-quark pairs known as quarkonia. However, the medium modification of heavy-flavour hadron production includes also the contribution of Cold Nuclear Matter (CNM) effects such as shadowing or nuclear breakup in addition to the QGP effects. Proton--nucleus collisions, where no QGP is expected, are used to measure CNM effects on quarkonium production. Finally, quarkonium measurements in proton--proton collisions are used as reference for both heavy-ion and proton-ion collisions. ALICE measurements of quarkonia at forward rapidity for various energies and colliding systems (pp, p--Pb, Pb--Pb and Xe--Xe) during the LHC Run 1 and Run 2 periods will be discussed.