# High luminosity fixed-target experiment at the LHC

## TL;DR

This paper discusses the potential for high-luminosity fixed-target experiments at the LHC using bent crystals or gas targets, enabling advanced studies in nucleon structure, quark-gluon plasma, and spin physics with existing detectors.

## Contribution

It reviews technical solutions for implementing high-luminosity fixed-target experiments at the LHC with ALICE and LHCb detectors, highlighting their scientific potential.

## Key findings

- Potential to study $pp$, $p$d, $p$A, Pb$p$, and PbA collisions at high energies
- Technical feasibility of using bent crystals and gas targets at LHC
- Enhanced capabilities for spin physics and partonic structure studies

## Abstract

By extracting the beam with a bent crystal or by using an internal gas target, the multi-TeV proton and lead LHC beams allow one to perform the most energetic fixed-target experiments ever and to study $pp$, $p$d and $p$A collisions at $\sqrt{s_{NN}}=115$ GeV and Pb$p$ and PbA collisions at $\sqrt{s_{NN}}=72$ GeV with high precision and modern detection techniques. Such studies would address open questions in the domain of the nucleon and nucleus partonic structure at high-$x$, quark-gluon plasma and, by using longitudinally or transversally polarised targets, spin physics. In this paper, we will review the technical solutions to obtain a high-luminosity fixed-target experiment at the LHC and will discuss their possible implementations with the ALICE and LHCb detectors.