Astrophysically important 26Si states studied with the 28Si(p,t)26Si reaction. II. Spin of the 5.914-MeV 26Si level and galactic 26Al production

The 28Si(p,t)26Si reaction has been studied to resolve a controversy surrounding the properties of the 26Si level at 5.914 MeV and its contribution to the 25Al(p,γ)26Si reaction rate in novae, which affects interpretations of galactic 26Al observations. Recent studies have come to contradictory conclusions regarding the spin of this level (0+ or 3+), with a 3+ assignment implying a large contribution by this level to the 25Al(p,γ)26Si reaction rate. We have extended our previous study [Bardayan et al., Phys. Rev. C 65, 032801(R) (2002)] to smaller angles and find the angular distribution of tritons populating the 5.914-MeV level in the 28Si(p,t)26Si reaction to be consistent with either a 2+ or 3+ assignment. We have calculated reaction rates under these assumptions and used them in a nova nucleosynthesis model to examine the effects of the remaining uncertainties in the 25Al(p,γ)26Si rate on 26Al production in novae