$\bar{K}NN$ quasi-bound state and the $\bar{K}N$ interaction: coupled-channel Faddeev calculations of the $\bar{K}NN - \pi \Sigma N$ system

TL;DR

This study uses coupled-channel Faddeev calculations to analyze the $ar{K}NN$ quasi-bound state, confirming earlier results and showing how different $ar{K}N$ potentials affect the state’s energy and width.

Contribution

It provides a detailed analysis of the $ar{K}NN$ system using coupled-channel methods and compares the effects of different $ar{K}N$ interactions on the quasi-bound state.

Findings

Confirmed earlier binding energy and width estimates.

Energy-independent potentials yield shallower, narrower states.

Comparison with other models highlights interaction dependence.

Abstract

Coupled-channel three-body calculations of an $I=1/2$, $J^{\pi}=0^-$ $\bar{K}NN$ quasi-bound state in the $\bar{K}NN - \pi \Sigma N$ system were performed and the dependence of the resulting three-body energy on the two-body $\bar{K}N - \pi \Sigma$ interaction was investigated. Earlier results of binding energy $B_{K^-pp} \sim 50 -70$ MeV and width $\Gamma_{K^-pp} \sim 100$ MeV are confirmed [N.V. Shevchenko {\it et al.}, Phys. Rev. Lett. {\bf 98}, 082301 (2007)]. It is shown that a suitably constructed energy-independent complex $\bar{K}N$ potential gives a considerably shallower and narrower three-body quasi-bound state than the full coupled-channel calculation. Comparison with other calculations is made.