Calculations of $K^{-}$ nuclear quasi-bound states based on chiral meson-baryon amplitudes

Abstract

In-medium $\bar{K}N$ scattering amplitudes developed within a new chirally motivated coupled-channel model due to Cieply and Smejkal that fits the recent SIDDHARTA kaonic hydrogen 1s level shift and width are used to construct $K^{-}$ nuclear potentials for calculations of $K^{-}$ nuclear quasi-bound states. The strong energy and density dependence of scattering amplitudes at and near threshold leads to $K^{-}$ potential depths $-Re{V}_K\approx 80-120$ MeV. Self-consistent calculations of all $K^{-}$ nuclear quasi-bound states, including excited states, are reported. Model dependence, polarization effects, the role of p-wave interactions, and two-nucleon $K^{-}NN\to YN$ absorption modes are discussed. The $K^{-}$ absorption widths ${\Gamma }_K$ are comparable or even larger than the corresponding binding energies $B_K$ for all $K^{-}$ nuclear quasi-bound states, exceeding considerably the level spacing. This discourages search for $K^{-}$ nuclear quasi-bound states in any but lightest nuclear systems.

Comments: 12 pages, 11 figures