Abstract
Background: Resonances observed through elastic scattering of protons on N can provide information about the partial widths, spin parities, and energies of excited states in O near the proton separation energy. This is the same energy region important for the nuclear astrophysics reactions NO and NC. While previous measurements have been made, they are limited in scope, especially in their angular coverage. Purpose: Obtain additional NN reaction data which can be used in a global multiple-channel -matrix analysis of the O compound nucleus in order to better constrain the level parameters of states which contribute to the reaction NO. Methods: Measure the excitation functions of NN over an energy range from 0.6 to 1.8 MeV at laboratory angles of 90, 105, 135, 150, and 165. The reaction NC was measured concurrently. Results: Ratios of the excitation functions were extracted from the yield data. Resonances were identified in the yield ratio data which correspond to previously reported levels in O. An -matrix analysis, which fits the present data as well as previous measurements from the literature simultaneously, finds reasonable agreement between the current measurements and those in the literature. Conclusions: The additional data from this measurement will be combined with previous literature data in a comprehensive -matrix analysis of reactions which populate O over a similar energy region.
- Received 16 December 2011
DOI:https://doi.org/10.1103/PhysRevC.85.038801
©2012 American Physical Society