Pi-mesic decays of A = 4 hypernuclei

Angular distributions and energy spectra for the decay modes _Λ⁴He→π^?p³He, _Λ⁴H → π^?p³H, _Λ⁴H → π^?n³He are calculated and compared with experiment. Final state nuclear interactions have been adjusted to fit the corresponding scattering data. With S-, P- and D-wave interactions we were able to obtain reasonably good agreement with the experimental decay spectra. It is suggested that the _Λ⁴H → π^?n³He decay spectra may be decisive in selecting the right set of p³H complex phase shifts from several possible solutions.