Proton-unbound excited states of S have been populated with the S()S reaction at a beam energy of 24 MeV. Tritons corresponding to S states with – MeV were momentum analyzed with a high resolution quadrupole-dipole-dipole-dipole (Q3D) magnetic spectrograph at six angles ranging from to . We report a statistically significant detection of an astrophysically important state at (2) keV, whose existence as a third state in this region has been under debate. Using updated nuclear structure information, we present a new set of proposed S-P mirror assignments for S, in which this state is tentatively assigned a spin of 7/2. This level, corresponding to a P + resonance at 271 keV, is likely to have a significant influence on the P()S reaction rate in explosive hydrogen burning in classical novae.
- Received 25 July 2013
- Published 27 November 2013
©2013 American Physical Society