The rho meson in a scenario of pure chiral restoration

TL;DR

This paper investigates the effects of a hypothetical pure chiral restoration on the rho meson using QCD sum rules, revealing a significant spectral shift and broadening without assuming peak position shifts.

Contribution

It introduces a scenario where only chiral symmetry breaking condensates are removed, analyzing its impact on the rho meson spectral properties.

Findings

Rho spectral moment drops by about 120 MeV.

Rho width can reach approximately 600 MeV without peak shift.

Pure chiral restoration significantly alters rho meson spectral features.

Abstract

Based on QCD sum rules we explore the consequences of a pure chiral restoration scenario for the rho meson, where all chiral symmetry breaking condensates are dropped whereas the chirally symmetric condensates remain at their vacuum values. This pure chiral restoration scenario causes the drop of the rho spectral moment by about 120 MeV. The complementarity of mass shift and broadening is discussed. A simple parametrization of the rho spectral function leads to a width of about 600 MeV if no shift of the peak position is assumed.