Abstract
Angular distributions of the relative cross sections and analyzing powers have been measured for the (p→,O reaction in ≊500 keV steps for excitation energies in between 17.8 and 24.9 MeV. All E1 and E2 transition matrix elements were determined using a partial-wave analysis. Below 22 MeV, little quadrupole strength was found in excess of that predicted in direct capture calculations. A clear enhancement of the E2 cross section was observed at energies above 22 MeV. Our data indicate that about 10% of the isoscalar E2 sum rule for is exhausted in the decay channel between 18 and 25 MeV, with approximately (3/4 of this integrated strength concentrated between 22 and 25 MeV. The E2 strength seen in (γ,) is strikingly different from that observed in (α,α’) or (α,α’p). The effect of the M1 state at =18.8 MeV previously found in (p,γ) studies is clearly observed.
- Received 25 June 1987
DOI:https://doi.org/10.1103/PhysRevC.37.2289
©1988 American Physical Society