Neutrino-nucleus reactions and muon capture in 12C

A. SAMANA, F. KRMPOTIC´, A. MARIANO

Physical Review C

The American Physical Society

Año: 2005 vol. 71 p. 443191 - 4431914

The neutrino-nucleus cross section and the muon-capture rate are discussed within a simple formalism thatfacilitates nuclear structure calculations. The corresponding formulas depend on only four types of nuclear matrix elements currently used in nuclear beta decay. We have also considered nonlocality effects arising from the velocity-dependent terms in the hadronic current. We show that for both observables in 12C the higher order relativistic corrections are of the order of 5% only and therefore do not play a significant role. As a nuclear model framework we use the projected quasiparticle random-phase approximation and show that the number projection plays a crucial role in removing the degeneracy between the proton-neutron two-quasiparticle states at the level of the mean field. Comparison is done with both the experimental data and the previous shell model calculations. The possible consequences of the present study on the determination of the muon neutrino to electron neutrino oscillation probability are briefly addressed.