Proton resonances inSi28fromEx=12.5 to 13.4MeV

The ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$(p,p) and ($\mathrm{p},{\alpha }_0$) differential cross sections were measured in the range $E_{\mathrm{p}}=0.92\mathrm{} \mathrm{to} 1.85$ MeV with an overall resolution of 350 to 400 eV (full width at half maximum.) Resonance parameters were extracted for 31 resonances with a multilevel, multichannel, $R$-matrix analysis code; these parameters include resonance energy, total angular momentum, partial elastic and inelastic widths, and channel spin and orbital angular momentum mixing ratios. Eleven analog states were identified, and the Coulomb displacement energies and spectroscopic factors were calculated. For the $2^{+}$ resonance at $E_{\mathrm{p}}=1.37\mathrm{}$ MeV the entrance orbital angular momentum mixing ratio was determined. The relevance of this mixing ratio to a previous test of time reversal invariance is discussed.