A Divergence-Free Method to Extract Observables from Meson Correlation Functions

TL;DR

This paper introduces a divergence-free approach to extract physical observables from meson correlation functions, enabling precise calculations of meson masses and quark-gluon plasma conductivity.

Contribution

A novel divergence-free spectral representation method combined with Dyson-Schwinger and Bethe-Salpeter equations for improved analysis of meson properties.

Findings

Calculated in-vacuum meson masses

Determined electrical conductivity of quark-gluon plasma

Method applicable to various strong-interaction observables

Abstract

Correlation functions provide information on the properties of mesons in vacuum and of hot nuclear matter. In this Letter, we present a new method to derive a well-defined spectral representation for correlation functions. Combining this method with the quark gap equation and the inhomogeneous Bethe-Salpeter equation in the rainbow-ladder approximation, we calculate in-vacuum masses of light mesons and the electrical conductivity of the quark-gluon plasma. The analysis can be extended to other observables of strong-interaction systems.