Calculations of ordinary and radiative muon capture on 58,60,62Ni

Abstract

The photon spectra and total radiative muon capture rate on heavy nuclei have been calculated for the first time using a microscopic description of the nuclear excitation function. The quasiparticle random phase approximation has been used to calculate the excitation spectra and transition amplitudes of ordinary and radiative muon capture in 58,60,62Ni. The parameters of the phenomenological nuclear spin-isospin residual interaction have been determined by comparison of the calculated and experimentally observed distributions of the transition strength over the excitation energies. The strength functions of Gamow-Teller ( σt ±) and spin-dipole ( r[ Y 1 σ] 0,1,2 t −) transitions are calculated and compared with the experimental data. The sum rule for the Gamow-Teller transitions is also considered. The nuclear amplitude of radiative muon capture has been treated in the framework of the standard impulse approximation and also in the modified impulse approximation, which takes into account the continuity equation for electromagnetic current. The calculated total rates of ordinary muon capture are close to the experimental data.