Abstract
In view of the recent experiments on neutrino oscillations performed by the LSND and KARMEN Collaborations as well as future experiments, we present new theoretical results of the flux-averaged and cross sections. The approaches used are charge-exchange random-phase approximation (RPA), charge-exchange RPA among quasiparticles (QRPA), and the shell model. With a large-scale shell-model calculation the exclusive cross sections are in nice agreement with the experimental values for both reactions. The inclusive cross section for coming from the decay-in-flight of is (when Hartree-Fock wave functions are used), to be compared to the experimental value of while the one due to coming from the decay-at-rest of is which agrees within experimental error bars with the measured values. The shell-model prediction for the decay-in-flight neutrino cross section is reduced compared to the RPA one, namely This is mainly due to the different kind of correlations taken into account in the calculation of the spin modes (in particular, because of the quenching in the channel) and partially due to the shell-model configuration basis which is not large enough, as we show using arguments based on sum rules. Results for exclusive and inclusive muon capture rates and decay are given and are close to the experimental findings.
- Received 27 January 2000
DOI:https://doi.org/10.1103/PhysRevC.62.015501
©2000 American Physical Society