Radiative proton capture to excited states in 16O.

Abstract

The radiative proton capture reaction on $^{15}\mathrm{N}$ was measured over the energy region ${E}_{p}$=20--90 MeV. Presented are experimental differential cross sections at ${\ensuremath{\theta}}_{\ensuremath{\gamma}}$=60\ifmmode^\circ\else\textdegree\fi{} for captures populating the ground and various excited states of $^{16}0$. Differential cross sections and analyzing-power angular distributions are presented at a proton energy of ${E}_{p}$=49.69 MeV. Calculations from a phenomenological direct-semidirect and a more detailed relativistic model describe cross sections well, but are less satisfactory in describing analyzing powers. Results of the energy-dependence measurements show that there are giant resonances built on all the excited states investigated.