$K^-pp$ system with chiral SU(3) effective interaction

TL;DR

This study investigates the $K^-pp$ system using a variational approach with realistic interactions, finding a weakly bound state with a smaller binding energy than previously suggested and estimating its decay width.

Contribution

It introduces a new calculation of the $K^-pp$ system using chiral SU(3) effective interactions and considers uncertainties in subthreshold extrapolations.

Findings

Weakly bound $K^-pp$ state with $B = (19 extpm 3)$ MeV

Decay width estimated between 40 and 70 MeV

Binding energy smaller than previous predictions

Abstract

The $K^-pp$ system is investigated using a variational approach with realistic two-body interactions: the Argonne v18 $NN$ potential and an energy dependent $\bar{K}N$ effective interaction derived from chiral SU(3) coupled-channel dynamics. Uncertainties in subthreshold extrapolations of the $\bar{K}N$ interaction are considered. A weakly bound $K^-pp$ state is found, with a binding energy $B = (19\pm 3)$ MeV substantially smaller than suggested in previous calculations. The decay width $\Gamma(K^-pp\to \pi\Sigma N)$ is estimated to range between about 40 and 70 MeV.