Testing the K^--nucleus interaction in (K_stop^-, π) reactions

We have compared various models of the K^- optical potential and tested them in fits to the available K^- atomic data. The quality of the fits is satisfactory for both the relatively 'shallow' optical potentials derived from chirally motivated models and for the 'deep' potentials based on phenomenological analyses. We show that (K_stop^-, π) hypernuclear production rates are very sensitive to the details of the kaonic bound state wave function. The reaction is thus suitable to distinguish between K^- optical potentials.