Exact calculation of proton decay rates from excited states in spherical nuclei

An {ital exact} approach for the determination of proton-decay widths in spherical nuclei is presented. It consists of solving numerically the one-dimensional time-dependent Schr{umlt o}dinger equation for initial proton quasistationary states obtained in the framework of a single-particle model. From the time dependence of the metastable state one can infer the dynamics of the decay and calculate the lifetime. The validity of this approach is demonstrated and quantitative comparisons with existing approximate, stationary methods are reviewed. Finally, the advantages and perspectives of this new method are discussed. {copyright} {ital 1999} {ital The American Physical Society}