# Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production

## TL;DR

This paper explores the feasibility of using the LHC's fixed-target mode with lead beams to study heavy-ion collisions, focusing on quarkonium and Drell-Yan production, and presents simulation results for potential measurements.

## Contribution

It demonstrates the potential of AFTER@LHC to extend heavy-ion physics studies into new energy and rapidity domains, especially for quarkonium and Drell-Yan observables.

## Key findings

- Feasibility of studying $Upsilon(nS)$, $J/Cpsi$, and $Cpsi(2S)$ production in new domains.
- Simulations show potential for analyzing nuclear modification of partonic densities.
- Supports the use of quarkonia as probes of quark-gluon plasma formation.

## Abstract

We outline the case for heavy-ion-physics studies using the multi-TeV lead LHC beams in the fixed-target mode. After a brief contextual reminder, we detail the possible contributions of AFTER@LHC to heavy-ion physics with a specific emphasis on quarkonia. We then present performance simulations for a selection of observables. These show that $\Upsilon(nS)$, $J/\psi$ and $\psi(2S)$ production in heavy-ion collisions can be studied in new energy and rapidity domains with the LHCb and ALICE detectors. We also discuss the relevance to analyse the Drell-Yan pair production in asymmetric nucleus-nucleus collisions to study the factorisation of the nuclear modification of partonic densities and of further quarkonia to restore their status of golden probes of the quark-gluon plasma formation.