Revised decay properties of the key 93-keV resonance in the Mg25(p,γ) reaction and its influence on the MgAl cycle in astrophysical environments

The $\ensuremath{\gamma}$-decay properties of an excited state in $^{26}\mathrm{Al}$ at 6398.3(8) keV have been reexamined using the $^{11}\mathrm{B}+^{16}\mathrm{O}$ fusion-evaporation reaction. This level represents a key 93.1(8)-keV resonance in the $^{25}\mathrm{Mg}+p$ system and its relative branching to the $^{26}\mathrm{Al}$ ground state, ${f}_{0}$, has been determined to be $0.76\phantom{\rule{0.16em}{0ex}}\ifmmode\pm\else\textpm\fi{}0.03$ (stat.) $\ifmmode\pm\else\textpm\fi{}0.10$ (syst.). This is a significantly higher value than the most recent evaluation and implies a considerable increase in the production of cosmic $\ensuremath{\gamma}$ rays from $^{26}\mathrm{Al}$ radioactivity.