Progress in the Glauber model at collider energies

TL;DR

This paper reviews recent theoretical and experimental advances in the Glauber model, highlighting its validation and application in high-energy collider experiments involving protons and nuclei at LHC and RHIC.

Contribution

It summarizes key developments over the past 10-15 years, including improved descriptions of nuclear densities, subnucleonic effects, and collision centrality determination, enhancing the model's accuracy.

Findings

Validation of Glauber model for high-energy collisions

Improved nuclear density and fluctuation descriptions

Constraints on quark-gluon plasma initial conditions

Abstract

We review the theoretical and experimental progress in the Glauber model of multiple nucleon and/or parton scatterings, after the last 10--15 years of operation with proton and nuclear beams at the CERN Large Hadron Collider (LHC) and with various light and heavy colliding ions at the BNL Relativistic Heavy Ion Collider (RHIC). The main developments and the state-of-the-art of the field are summarized. These encompass measurements of the inclusive inelastic proton and nuclear cross sections, advances in the description of the proton and nuclear density profiles and their fluctuations, inclusion of subnucleonic degrees of freedom, experimental procedures and issues related to the determination of the collision centrality, validation of the binary scaling prescription for hard scattering cross sections, and constraints on transport properties of quark-gluon matter from varying initial-state conditions in relativistic hydrodynamics calculations. These advances confirm the validity and usefulness of the Glauber formalism for quantitative studies of QCD matter produced in high-energy collisions of systems, from protons to uranium nuclei, of vastly different size.