Chiral dynamics with vector fields: an application to $\pi\pi$ and $\pi K$ scattering

TL;DR

This paper presents a theoretical analysis of Goldstone boson scattering using chiral Lagrangians with vector mesons, successfully predicting phase shifts in $$ and $$ channels up to 1.2 GeV.

Contribution

It introduces a novel extrapolation approach for subthreshold amplitudes within chiral dynamics, maintaining causality and unitarity constraints.

Findings

Leading order amplitudes agree with experimental phase shifts

Method accurately predicts $$ and $$ scattering up to 1.2 GeV

Demonstrates the effectiveness of vector fields in chiral models

Abstract

A theoretical study of Goldstone boson scattering based on the chiral Lagrangian with vector meson fields is presented. In application of a recently developed novel approach we extrapolate subthreshold partial-wave amplitudes into the physical region. The constraints set by micro-causality and coupled-channel unitarity are kept rigourously. It is shown that already the leading order subthreshold amplitudes lead to s- and p-wave $\pi\pi$ and $\pi K$ phase shifts are in agreement with the experimental data up to about 1.2 GeV.