High Energy Hadron Production, Self-Organized Criticality and Absorbing State Phase Transition

TL;DR

This paper proposes that light nuclei production in high energy nuclear collisions results from a non-equilibrium evolution leading to self-organized criticality and an absorbing state phase transition, challenging the equilibrium hadronic medium assumption.

Contribution

It introduces a novel non-equilibrium framework explaining hadron formation as an absorbing state phase transition, diverging from traditional equilibrium models.

Findings

Light nuclei production aligns with a non-equilibrium criticality model.

Hadron formation occurs as an absorbing state transition at the confinement point.

Equilibrium assumptions are insufficient to explain observed production rates.

Abstract

In high energy nuclear collisions, production rates of light nuclei agree with the predictions of an ideal gas at a temperature $T=155 \pm 10$ MeV. In an equilibrium hadronic medium of this temperature, light nuclei cannot survive. In this contribution, we suggest that the observed behavior is due to an evolution in global non-equilibrium, leading to self-organized criticality and to hadron formation as an absorbing state phase transition for color degrees of freedom. At the confinement point, the initial quark-gluon medium becomes quenched by the vacuum, breaking up into all allowed free hadronic and nuclear mass states, without (or with a very short-live) subsequent formation of thermal hadronic medium.