Fate of critical fluctuations in an interacting hadronic medium using maximum entropy distributions

TL;DR

This study investigates how critical fluctuations evolve in an expanding hadronic medium using maximum entropy distributions, revealing that correlations can persist through the system's evolution if coupling is strong enough.

Contribution

It introduces a novel approach coupling 3d Ising model cumulants with maximum entropy distributions to track critical fluctuations in a hadronic transport simulation.

Findings

Critical fluctuations propagate throughout the system's evolution.

Resonance regeneration and isospin randomization significantly affect fluctuations.

Strong coupling maintains correlations after kinetic freeze-out.

Abstract

We study the evolution of critical fluctuations in an expanding system within a hadronic transport approach. The initialization of the system with critical fluctuations is achieved by coupling the ideal hadron resonance gas cumulants to the ones from the 3d Ising model and generating the net and total particle number distribution from the principle of maximum entropy. These distributions are then evolved using realistic hadronic interactions. We systematically investigate the evolution of the critical fluctuations initialized at various temperatures and chemical potentials along a freeze-out line. We find that resonance regeneration and isospin randomization processes have the strongest influence on the evolution of the fluctuations. Additionally, the sets of particles coupled to the critical mode are modified to assess the strength of the propagation of correlations through interactions. We find that in the scaling region of the critical point correlations are propagated through the whole collisional history and are still present after the kinetic freeze-out of the matter if the coupling strength is large enough.