Kaonic atoms and in-medium K-N amplitudes II: interplay between theory and phenomenology

Abstract: A microscopic kaonic-atom optical potential $V^{(1)}_{K^-}$ is constructed, using the Ikeda-Hyodo-Weise NLO chiral $K^-N$ subthreshold scattering amplitudes constrained by the kaonic hydrogen SIDDHARTA measurement, and incorporating Pauli correlations within the Waas-Rho-Weise generalization of the Ericson-Ericson multiple-scattering approach. Good fits to kaonic atom data over the entire periodic table require additionally sizable $K^-NN$--motivated absorptive and dispersive phenomenological terms, in agreement with our former analysis based on a post-SIDDHARTA in-medium chirally-inspired NLO separable model by Ciepl\'{y} and Smejkal. Such terms are included by introducing a phenomenological potential $V^{(2)}_{K^-}$ and coupling it self consistently to $V^{(1)}_{K^-}$. Properties of resulting kaonic atom potentials are discussed with special attention paid to the role of $K^-$-nuclear absorption and to the extraction of density-dependent amplitudes representing $K^-$ multi-nucleon processes.