Pion scattering, light resonances, and chiral symmetry restoration at nonzero chiral imbalance and temperature

Abstract

We calculate the pion scattering amplitude at nonzero temperature and nonzero μ5, the chemical potential associated to chiral imbalance in a locally P-breaking scenario. The amplitude is calculated up to next-to-leading order in Chiral Perturbation Theory and is unitarized with the Inverse Amplitude Method to generate the poles of the f0(500) and ρ(770) resonances. Within the saturation approach, the thermal f0(500) pole allows to determine Tc(μ5), the transition temperature for chiral symmetry restoration. Our results confirm the growing behavior of Tc(μ5) found in previous works and, through a fit to lattice results, we improve the uncertainty range of the low-energy constants associated to μ5 corrections in the chiral Lagrangian. The results for the ρ(770) pole are compatible with previous works regarding the dilepton yield in heavy-ion collisions. Published by the American Physical Society 2024