Threshold cusp structures in multi-channel scattering

TL;DR

This paper investigates the cusp structures in multi-channel scattering, emphasizing isospin symmetry breaking effects and their implications for understanding exotic hadrons.

Contribution

It introduces a new formulation of the scattering amplitude to analyze cusp structures at closely spaced thresholds, highlighting their relation via isospin symmetry.

Findings

Cusp structures at nearby thresholds are interconnected through isospin symmetry.

The new formulation simplifies the analysis of cusp phenomena in multi-channel scattering.

Insights into exotic hadron properties are gained from cusp shape analysis.

Abstract

We study the behavior of the cusp structures focusing on the isospin symmetry breaking effects. The properties of the exotic hadrons are reflected in the shape of the cusp structures. In realistic hadron scatterings, the threshold energies of the isospin partners appear within a small energy region. For a detailed analysis of such systems, it is essential to study the behavior of the cusp structures arising at two closely spaced thresholds. In this work, we introduce a convenient formulation of the scattering amplitude and demonstrate that the cusp structures at two nearby thresholds are related through the isospin symmetry.