Background: The properties of resonances in ${}^{26}\mathrm{Si}$ are important to better constrain the ${}^{25}\mathrm{Al}(p,\gamma ){}^{26}\mathrm{Si}$ reaction rate relevant to the synthesis of galactic ${}^{26}\mathrm{Al}{}^{\mathrm{gs}}$ and energy generation in explosive stellar environment at higher temperature.

Purpose: ${}^{25}\mathrm{Al}+p$ elastic scattering was measured to further constrain and investigate disagreements in resonance parameters for the high-lying excited states of ${}^{26}\mathrm{Si}$ with high statistics and without background contamination within the target.

Methods: The experiment was performed by bombarding a thick ${\mathrm{H}}_2$ target with an ${}^{25}\mathrm{Al}$ radioactive ion beam. The resonances at excitation energies of 6.6–8.3 MeV in the ${}^{26}\mathrm{Si}$ compound nucleus were studied at the low-energy radioactive-ion beam facility CRIB (Center for Nuclear Study Radioactive Ion Beam separator) at the University of Tokyo.

Results: Six resonant states were observed and their resonance parameters were extracted by an $R$-matrix analysis. Our resonance parameters for two levels are in good agreement with the results of previous studies, while for four others, excitation energy, proton partial width, and spin-parity assignment disagree with the results of recent study via elastic scattering of ${}^{25}\mathrm{Al}+p$.

Conclusion: The parameters of resonant states in ${}^{26}\mathrm{Si}$ determined in the present work for the ${}^{25}\mathrm{Al}(p,\gamma ){}^{26}\mathrm{Si}$ reaction rate are consistent with that of the previous result, solving spin-parity assignment discrepancies between experiments, relevant at higher temperatures.

• Received 19 May 2014
• Revised 16 July 2014

DOI:https://doi.org/10.1103/PhysRevC.90.035805