Critical Phenomena in Hadronic and DIS Processes

TL;DR

The paper develops a unified thermodynamic view of critical phenomena in hadronic and DIS processes by employing the van der Waals equation of state to describe the dense partonic matter produced in high-energy collisions. It connects a nuclear liquid–gas-like phase transition to a saturation transition in DIS, using statistical models for structure functions and reduced-variable EoS to bridge large and small systems. The results highlight universal aspects of strongly interacting matter, with a density-driven gas–fluid transition underpinning both hadronic and DIS observables, and emphasize mappings between experimental signatures and thermodynamic states. This framework offers a common language to interpret phase behavior across pp, pA, AA, and ep/eA collisions, with implications for modeling entropy production and the emergence of collective phenomena.

Abstract

We compare the critical phenomena (e.g. phase transitions, crossover) in proton-proton, proton-nucleus scattering and in lepton-proton deep inelastic scattering (DIS) systems.

Figures (2)

• Figure 1: Pressure isotherm in (a) ($p$, $v$) and (b) ($p$, $n$), calculated in the quantum van der Waals equation of state (see details in ref. VAG1). The full circle on the $T=T_c$ isotherm corresponds to the critical point. Shaded grey area in (b) accounts for the mixed phase region. This figure has been borrowed from ref. VAG1.
• Figure 2: The pressure-to-density dependence calculated, in arbitrary units, from Eq.(\ref{['VdW11']}).