Coulomb-nuclear interference in hadronic atoms

Abstract

A rapidly converging expansion method for the Coulomb T operator is applied to relate S-wave strong interaction shifts and widths in the ground state of mesic atoms to the pure hadronic scattering length in the corresponding scattering system. The result improves the accuracy of the Deser formula and, in combination with other methods, allows a determination of Coulomb corrections to S-wave scattering lengths in a model-independent way. In detail, the author discusses various corrections in the ground state of kaonic hydrogen, where a discrepancy between bound-state and scattering data exists which is not yet understood. Further applications are given for heavier pionic atoms and atomic protonium.