S-matrix analysis of the baryon electric charge correlation

TL;DR

This paper uses the S-matrix approach to compute the baryon electric charge correlation in an interacting hadron gas, showing improved agreement with lattice QCD data by accurately incorporating interactions and resonances.

Contribution

It introduces an S-matrix based method to analyze baryon charge correlations, enhancing the modeling of hadron interactions compared to traditional resonance gas models.

Findings

S-matrix approach improves agreement with lattice QCD data

Proper treatment of resonances enhances model accuracy

Pion-nucleon interactions significantly influence charge correlations

Abstract

We compute the correlation of the net baryon number with the electric charge ($\chi_{BQ}$) for an interacting hadron gas using the S-matrix formulation of statistical mechanics. The observable $\chi_{BQ}$ is particularly sensitive to the details of the pion-nucleon interaction, which are consistently incorporated in the current scheme via the empirical scattering phase shifts. Comparing to the recent lattice QCD studies in the $(2+1)$-flavor system, we find that the natural implementation of interactions and the proper treatment of resonances in the S-matrix approach lead to an improved description of the lattice data over that obtained in the hadron resonance gas model.