Chemical potential differentials in the QCD phase diagram from heavy-ion isobar collisions

TL;DR

This paper uses Bayesian analysis of heavy-ion isobar collision data to precisely measure chemical potential differences in the QCD phase diagram, providing insights into conserved-charge correlations and thermodynamics.

Contribution

It introduces a Bayesian thermal analysis method applied to isobar collision data, reducing uncertainties and enabling detailed exploration of the four-dimensional QCD phase diagram.

Findings

Chemical potential differences are extracted with reduced systematic uncertainties.

Results agree with lattice-QCD and Chiral Mean Field model predictions.

Isobar collisions serve as a high-precision probe of QCD thermodynamics.

Abstract

Temperature and baryon, charge, and strangeness chemical potentials characterize QCD matter under extreme conditions. Differences between these chemical potentials and their ratios probe conserved-charge correlations and the system's response in the multidimensional QCD phase diagram. We extract these quantities from STAR Ru+Ru and Zr+Zr isobar collisions using a Bayesian thermal analysis of hadron yields, which substantially reduces systematic uncertainties, and compare them with Taylor-expanded lattice-QCD and Chiral Mean Field model predictions. Isobar collisions thus emerge as a precision probe of four-dimensional QCD thermodynamics.