The magnitude of nuclear transition matrix elements calculated in the particle-hole model often must be renormalized to give agreement with experiment. We introduce 2p-2h state admixtures in the ground state (of "closed-shell nuclei") and consider transitions to the usual configuration-mixed p-h states. The resulting renormalized transition matrix elements are, for reasonable choices of the ground-state correlations, in better agreement with experiment. Because proper treatment of the excited states is also required for detailed comparison with experiment in the case of partial transitions, we study the total muon-capture rate using the closure approximation. It is found that introduction of 2p-2h states in the ground state does not remove the theoretical-experimental discrepancy for the total capture rate in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ if the usual range of values for the "average" neutrino momentum is adopted.

• Received 12 November 1971

DOI:https://doi.org/10.1103/PhysRevC.5.1540