Level structure of 26Si and its implications for the astrophysical reaction rate of 25Al(p,γ)26Si

A study of the level structure of 26 Si using in-beam γ-ray spectroscopy is presented. A full level scheme is derived incorporating all states lying below the proton threshold energy. The results are in good agreement with shell model predictions and one-to-one correspondence is found with states in the mirror nucleus 26 Mg. Additionally, a γ-decay branch is observed from a state at 5677.0(17) keV, which is assigned to a 1 + resonance important in the astrophysical reaction 25 Al(p,γ) 26 Si. The newly derived resonance energy, E r = 159.2(35) keV, has the effect of decreasing the reaction rate at the novae ignition temperature of ≈0. 1 GK by a factor of ≈2 when compared with the previous most precise measurement of this state.