Beyond the rainbow: effects from pion back-coupling

TL;DR

This paper explores how pion back-coupling influences light quark and meson properties using advanced non-perturbative equations, revealing significant unquenching effects across various meson types.

Contribution

It introduces a refined method for solving coupled Schwinger-Dyson and Bethe-Salpeter equations in the complex plane, explicitly including pion back-coupling effects.

Findings

Significant unquenching effects observed in light meson spectra.

Improved solution method for coupled equations in the complex plane.

Enhanced understanding of pion back-coupling impact on hadron properties.

Abstract

We investigate hadronic unquenching effects in light quarks and mesons. To this end we take into account the back-coupling of the pion onto the quark propagator within the non-perturbative continuum framework of Schwinger-Dyson equations (SDE) and Bethe-Salpeter equations (BSE). We improve on a previous approach by explicitly solving both the coupled system of DSEs and BSEs in the complex plane and the normalisation problem for Bethe-Salpeter kernels depending on the total momentum of the meson. As a result of our study we find considerable unquenching effects in the spectrum of light pseudoscalar, vector and axial-vector mesons.