System size dependence of pre-equilibrium and applicability of hydrodynamics in heavy-ion collisions

2023/07/17 by Victor E. Ambruş, Sören Schlichting, Ambruş, Victor E. +3 · 1 citation
Mathematics · Physics and Astronomy · #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Stochastic processes and statistical mechanics

paper · pdf · doi:10.48550/arxiv.2307.08306

openalex publication_date 2023/07/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We simulate the space-time dynamics of high-energy collisions based on a microscopic kinetic description, in order to determine the range of applicability of an effective description in relativistic viscous hydrodynamics. We find that hydrodynamics provides a quantitatively accurate description of collective flow when the average inverse Reynolds number Re^-1 is sufficiently small and the early pre-equilibrium stage is properly accounted for. By determining the breakdown of hydrodynamics as a function of system size and energy, we find that it is quantitatively accurate in central lead-lead collisions at LHC energies, but should not be used in typical proton-lead or proton-proton collisions, where the development of collective flow can not accurately be described within hydrodynamics.

Cited by

• Investigating the most active pp collisions (top 0.1%) using the tools developed by experiments at the LHC

Related

• Establishing the Range of Applicability of Hydrodynamics in High-Energy Collisions
• Quantifying the degree of hydrodynamic behaviour in heavy-ion collisions
• New theoretical developments on the early-time dynamics and approach to equilibrium in Heavy-Ion collisions
• Hydrodynamic Modeling for Relativistic Heavy Ion Collisions at RHIC and the LHC
• Relativistic hydrodynamics for heavy-ion collisions