Muon-Capture and Photon-Absorption Calculations in a Configuration-Mixing Model forO16

Abstract

The utility of multiparticle, multihole configuration mixing as a mechanism for resolving certain theoretical-experimental discrepancies for muon capture and photodisintegration on ${\mathrm{O}}^{16}$ is considered. An ${\mathrm{O}}^{16}$ ground state containing a two-particle, two-hole (2p-2h) component is assumed. The usual particle-hole odd-parity states are amended to contain three-particle, three-hole configuration admixtures consistent with the choice of the more complicated ground state. The results of the calculations indicate that the configuration-mixing model can appreciably lower the partial muon-capture rates to the lowest $0^{-}$, $1^{-}$, and $2^{-}$ states. Moreover, a shift in the energy distribution of the transition strength, obtained in the model calculations, lowers the capture rate and photodisintegration cross section in and below the giant-resonance region. However, correction terms, arising mainly from $0^{+}$ → $1^{+}$ (2p-2h) allowed Gamow-Teller transitions, seem to preclude a lowering of the total capture rate.