Calibrating the medium effects of light clusters in heavy-ion collisions

TL;DR

This paper uses Bayesian inference to estimate how light nuclear clusters are affected by the medium in heavy-ion collisions, revealing a temperature-dependent weakening of cluster interactions that impacts their abundance.

Contribution

It introduces a Bayesian approach to determine in-medium modifications of light clusters in heavy-ion collisions without relying on prior thermal assumptions.

Findings

Cluster-$\sigma$-meson coupling decreases with temperature.

Light cluster abundances decline faster with temperature than previously thought.

Model accurately reproduces H and He isotope multiplicities.

Abstract

We propose a Bayesian inference estimation of in-medium modification of the cluster self-energies from light nuclei multiplicities measured in selected samples of central $^{136,124}$Xe$+^{124,112}$Sn collisions with the INDRA apparatus. The data are interpreted with a relativistic quasi-particle cluster approach in the mean-field approximation without any prior assumption on the thermal parameters of the model. An excellent reproduction is obtained for H and He isotope multiplicities, and compatible posterior distributions are found for the unknown thermal parameters. We conclude that the cluster-$\sigma$-meson coupling is temperature dependent, becoming weaker when the temperature increases, in agreement with microscopic quantum statistical calculations. This implies a faster decrease of the light cluster abundances with temperature than previously estimated.