Correlations of net baryon number and electric charge in nuclear matter

TL;DR

This paper examines higher-order correlations between net baryon number and electric charge in nuclear matter, revealing their behavior near the liquid-gas phase transition and potential experimental signals.

Contribution

It provides a detailed analysis of sixth-order correlations and their sensitivity to phase transitions within the nonlinear Walecka model.

Findings

Strong correlations near the liquid-gas phase transition.

Higher order correlations are more sensitive than lower order ones.

Some correlations change sign along the chemical freeze-out line.

Abstract

We investigate the correlations between net baryon number and electric charge up to sixth order related to the interactions of nuclear matter at low temperature, and explore their relationship with the nuclear liquid-gas phase transition (LGPT) within the framework of the nonlinear Walecka model. The calculation shows that strong correlations between the baryon number and electric charge exist in the vicinity of LGPT, and the higher order correlations are more sensitive than the lower order ones near the phase transition. However, in the high-temperature region away from the LGPT the rescaled lower order correlations are relatively larger than most of the higher order ones. Besides, some of the fifth- and sixth-order correlations possibly change the sign from negative to positive along the chemical freeze-out line with the decrease of temperature. In combination with the future experimental projects at lower collision energies, the derived results can be referred to study the phase structure of strongly interacting matter and analyze the related experimental signals.