Exploration of resonance properties in chiral perturbation theory with explicit U_A(1) anomaly

TL;DR

This paper investigates how resonance properties in low-energy QCD are affected by the U_A(1) anomaly within chiral perturbation theory, analyzing their behavior at Nc=3 and in the large Nc limit.

Contribution

It explicitly incorporates the U_A(1) anomaly into chiral perturbation theory to study resonance properties and their Nc trajectories, providing new insights into low-energy QCD.

Findings

Resonance masses and widths are calculated for Nc=3.

Resonance pole trajectories are analyzed as Nc varies.

The impact of the U_A(1) anomaly on resonance properties is elucidated.

Abstract

We study the resonance properties within chiral perturbation theory by explicitly taking into account the U_A(1) anomaly effect. This assures we have the appropriate degrees of freedom of low energy QCD in the large Nc limit. We calculate the various resonance properties, such as mass, width and residues, for the physical case, i.e. Nc=3. Then we extrapolate the values of Nc to study the trajectories of resonance poles.