Distorted Pion Wave Function in the Pionic Decay of the Lightest Λ Hypernuclei

Abstract

The effect of pion distortions is studied in the π-mesonic decay [Formula: see text] of the lightest Λ hypernuclei. Reduction in the decay rates of both these nuclei is observed. This is in contrast to previous observations of enhancements in the decay rates of all nuclei ranging from [Formula: see text] to [Formula: see text]. The distorted wave function is evaluated using a theoretically deduced pion–nucleus optical potential. Calculations are also made using phenomenological optical potentials which fit the pion–nucleus scattering data quite well. Results with theoretical and phenomenological potentials are in fairly good agreement qualitatively, but the exact results are sensitive to the type of optical potential used.