Proton decay of ²⁶Si via the ²⁸Si(p,t)²⁶Si reaction and implications for ²⁵Al(p,γ)²⁶Si

The rate of the ²⁵Al(p,γ)²⁶Si reaction in novae is important to the production of galactic ²⁶Al, an important astronomical observable for its 1.809 MeV gamma ray. ²⁶Al has been catalogued near massive stars and found in presolar grains. The ²⁵Al proton capture reaction serves to bypass ²⁶Al^g:s: production since the subsequent ²⁶Si beta decay preferentially populates instead the isomeric state of ²⁶Al. Several recent studies have aimed to locate and characterize the first ℓ = 0 resonances in ²⁶Si above the ²⁵Al+p threshold, which would dominate the reaction rate at nova temperatures. We have studied several resonances in ²⁵Al(p,γ)²⁶Si via the ²⁸Si(p,t) ²⁶Si* reaction at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. In addition to measuring the angular distributions of the tritons, a partial implementation of the Oak Ridge Rutgers University Barrel Array (ORRUBA) was used to measure the coincident protons emitted from the decay of states in ²⁶Si above the proton threshold. We observe that the first ℓ = 0 state above the proton threshold decays essentially 100% of the time via proton emission, resulting in a proton branching ratio consistent with one.