Isospin mixing effects in low-energy $\bar{K}N - \pi \Sigma$ interaction

TL;DR

This paper develops a new coupled-channel potential for the ar{K}N- ext{}Sigma interaction, incorporating isospin breaking effects, and accurately predicts kaonic hydrogen properties and the mbda(1405) resonance structure.

Contribution

A novel strong coupled-channel potential for ar{K}N- ext{}Sigma interactions is constructed, including isospin breaking effects, suitable for precise few-body calculations.

Findings

Reproduces all existing experimental data.

Predicts the s level shift and width of kaonic hydrogen.

Analyzes the mbda(1405) resonance with one- and two-pole models.

Abstract

New strong coupled-channel $\bar{K}N - \pi \Sigma$ potential, reproducing all existing experimental data and suitable for using in an accurate few-body calculations, is constructed. Isospin breaking effects of direct inclusion of the Coulomb interaction and using of physical masses in calculations are investigated. The $1 s$ level shift and width of kaonic hydrogen, consistent with the scattering data, was obtained and the corresponding exact strong $K^- p$ scattering length was calculated. One- and two-pole form of $\Lambda(1405)$ resonance was considered.