Chirally motivated K^- nuclear potentials

In-medium subthreshold K̄N scattering amplitudes calculated within a chirally motivated meson-baryon coupled-channel model are used self consistently to confront K^- atom data across the periodic table. Substantially deeper K^- nuclear potentials are obtained compared to the shallow potentials derived in some approaches from threshold K̄N amplitudes, with ReV_K-^chiral=-(85±5) MeV at nuclear matter density. When K̄NN contributions are incorporated phenomenologically, a very deep K^- nuclear potential results, ReV_K-^chiral+phen.=-(180±5) MeV, in agreement with density dependent potentials obtained in purely phenomenological fits to the data. Self consistent dynamical calculations of K^-nuclear quasibound states generated by VK_K-^chiral are reported and discussed.