Parity and isospin nonconservation in 16O investigated via 15N(p vector, α)12C resonance reaction

The parity- and partially isospin-forbidden α0-decay from 16O* (Jπ=2-, T=1; Ex=12.9686 MeV) to 12C(g.s.) has been thoroughly investigated theoretically. Considering various strong and weak interaction models, the longitudinal AL and the irregular transverse Ab analyzing powers of the reaction 15N(p vector, α0)12C have been calculated in the energy range around the 2- resonance in 16O*. The isospin impurity due to the coupling with 2-, Ex=12.53 MeV excited level in 16O*, which has mainly a T=0 component, have been considered in the calculations. Energy anomalies for the expected interference effects, relevant for the experiments, have been found to be AL≅2.0x10-5 and Ab≅0.4x10-5. (orig.)