Measurement of the ${}^{25}\mathrm{Al}(\mathrm{d},\mathrm{n}{)}^{26}\mathrm{Si}$ reaction and impact on the ${}^{25}\mathrm{Al}(\mathrm{p},{\hat{\mathrm{I}}}^3{)}^{26}\mathrm{Si}$ reaction rate

Abstract

The ${}^{25}\mathrm{Al}(\mathrm{p},{\hat{\mathrm{I}}}^3{)}^{26}\mathrm{Si}$ reaction is part of a reaction network with impact on the observed galactic ${}^{26}$Al abundance. A new determination of the proton strength of the lowest $\ell =0$ proton-resonance in ${}^{26}$Si is required to more precisely calculate the thermal reaction rate. To this end, the ${}^{25}\mathrm{Al}(\mathrm{d},\mathrm{n}{)}^{26}\mathrm{Si}$ proton-transfer reaction is measured in inverse kinematics using an in-flight radioactive beam at the RESOLUT facility. Excitation energies of the lowest ${}^{26}$Si proton resonances are measured and cross sections are determined for the lowest $\ell =0$ resonance associated with the $3_3^{+}$ state at 5.92(2) MeV. Coupled reaction channels (CRC) calculations using FRESCO are performed to extract the $\ell =0$ spectroscopic factor for the $3_3^{+}$ state. The proton width for the $3_3^{+}$ state in ${}^{26}$Si is determined to be $\hat{I}{“}_p$=2.19(45) eV and the $(p,{\hat{I}}^3)$ resonance strength for the $3_3^{+}$ state is extracted as 26(10) meV. This resonance dominates the ${}^{25}\mathrm{Al}(\mathrm{p},{\hat{\mathrm{I}}}^3{)}^{26}\mathrm{Si}$ reaction rate above 0.2 GK.

8 pages, 7 figures