Photon emission rates near the critical point in the linear sigma model

TL;DR

This paper investigates how photon emission rates near the critical point in the linear sigma model vary with phase transitions, suggesting they could serve as probes for mapping the phase diagram in high-energy physics.

Contribution

It demonstrates the dependence of photon emission rates on effective masses near the critical point, providing a potential method to explore the phase diagram.

Findings

Photon emission rates depend on effective masses near the critical point.

Soft-photon emission shows sensitivity to phase transitions.

Photon rates could help map the phase diagram.

Abstract

Employing the linear sigma model, the effective masses of quasi-particle excitations are found to exhibit significant variations within the phase diagram, which has a critical point at non-zero chemical potential, where a first-order phase transition sets in. Soft-photon emission rates in lowest order display, for selected channels, a sensible dependence on the effective masses of the involved excitations and let us argue that they could map out the phase diagram.