K^- nuclear potentials from in-medium chirally motivated models

TL;DR

This paper develops a self-consistent method to construct K^- nuclear optical potentials using in-medium chiral models, improving the understanding of kaonic atom data and K^- quasibound states with enhanced potential depths.

Contribution

It introduces a new self-consistent scheme for deriving K^- nuclear potentials from chiral models, incorporating phenomenological terms to better match experimental data.

Findings

Real part of K^- potential is about 85 MeV at nuclear matter density.

Adding rho- and rho^2-dependent terms improves data agreement, increasing potential depth to around 180 MeV.

P-wave interactions are less significant compared to s-wave contributions.

Abstract

A self consistent scheme for constructing K^- nuclear optical potentials from subthreshold in-medium Kbar-N s-wave scattering amplitudes is presented and applied to analysis of kaonic atoms data and to calculations of K^- quasibound nuclear states. The amplitudes are taken from a chirally motivated meson-baryon coupled-channel model, both at the Tomozawa-Weinberg leading order and at the next to leading order. Typical kaonic atoms potentials are characterized by a real part -Re V(K^-;chiral)=(85+/-5) MeV at nuclear matter density, in contrast to half this depth obtained in some derivations based on in-medium Kbar-N threshold amplitudes. The moderate agreement with data is much improved by adding complex rho- and rho^2-dependent phenomenological terms, found to be dominated by rho^2 contributions that could represent Kbar-NN -> YN absorption and dispersion, outside the scope of meson-baryon chiral models. Depths of the real potentials are then near 180 MeV. The effects of p-wave interactions are studied and found secondary to those of the dominant s-wave contributions. The in-medium dynamics of the coupled-channel model is discussed and systematic studies of K^- quasibound nuclear states are presented.