The reaction 80Se(t,)79As has been investigated with an 18-MeV triton beam. Twenty-six levels of 79As (many of them previously unreported) have been identified up to about 3.5 MeV excitation energy. Angular distributions were measured and compared with distorted-wave Born-approximation calculations, in order to extract L values and spectroscopic factors. Most of the expected strength for pickup from the 2p and 1f52 orbitals is observed. Behavior of the low-lying negative-parity states for various As isotopes is presented and compared with the predictions of a rotational model with prolate deformation and Coriolis coupling. The observed first and second 92+ states in odd-A isotopes give further evidence for the shape transition suggested recently for this mass region.
NUCLEAR REACTIONS 80Se(t,)79As, E=18 MeV; measured (E,). 79As deduced levels, L, (J), spectroscopic factors. DWBA analysis, enriched target.