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

A self-consistent scheme for constructing K^- nuclear optical potentials from subthreshold in-medium K̄N 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 -ReVK^-chiral= 85±5 MeV at nuclear matter density, in contrast to half this depth obtained in some derivations based on in-medium K̄N threshold amplitudes. The moderate agreement with data is much improved by adding complex ρ- and ρ2-dependent phenomenological terms, found to be dominated by ρ2 contributions that could represent K̄NN→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.