Study of Si states important for Al nucleosynthesis in Novae

The production of the radioisotope Al in astrophysical environments is not understood, in part, because of large uncertainties in key reaction rates such as Al(p, γ Si. To reduce the uncertainty in this rate, we have studied the level structure of Si via a measurement of the angular and energy distribution of tritons from the (p, t i reaction. A total of 21 states in Si were observed, including a new state at 7019 keV. The excitation energies of several states were corrected, and the spin assignments for several states above the proton emission threshold were determined for the first time through a DWBA analysis of the angular distributions. Our results substantially clarify the level structure of Si and improve our understanding of the Al(p, γ)Si reaction rate.