High-precision (p,t) reaction to determine ^{25}Al(p,γ)^{26}Si reaction rates

Since the identification of ongoing Al-26 production in the universe, the reaction sequence Mg-24(p,gamma)Al-25(beta(+)nu)Mg-25(p,gamma)Al-26 has been studied intensively. At temperatures where the radiative capture on Al-25 (t(1/2) = 7.2 s) becomes faster than the beta(+) decay, the production of Al-26 can be reduced due to the depletion of Al-25. To determine the resonances relevant for the Al-25(p,gamma) Si-26 bypass reaction, we measured the Si-28(p,t)Si-26 reaction with high-energy precision using the Grand Raiden spectrometer at the Research Center for Nuclear Physics, Osaka. Several new energy levels were found above the p threshold and for known states excitation energies were determined with smaller uncertainties. The calculated stellar rates of the bypass reaction agree well with previous results, suggesting that these rates are well established.