Lowest l = 0 proton resonance in Si 26 and implications for nucleosynthesis of Al 26

Using a beam of the radioactive isotope $^{25}\mathrm{Al}$, produced with the new RESOLUT facility, we measured the direct $(d,n)$ proton-transfer reaction leading to low-lying proton resonances in $^{26}\mathrm{Si}$. We observed the lowest $l=0$ proton resonance, identified with the ${3}^{+}$ state at 5.914-MeV excitation energy. This result eliminates the largest uncertainty in astrophysical reaction rates involved in the nucleosynthesis of $^{26}\mathrm{Al}$.