New stellar reaction rates for ²⁵Mg(p,γ)²⁶Al and ²⁵Al(p,γ)²⁶Si

Existing experimental proton stripping reaction data on ²⁵Mg leading to threshold states in ²⁶Al are reinvestigated and reanalyzed in a consistent and improved manner. We use unbound state form factors in the DWBA analysis of the measured deuteron angular distributions to deduce absolute rather than relative proton partial widths. For higher-lying resonances these values are compared to widths obtained from (p,γ) work. It is also shown that several of the unique J^π values assigned previously to ²⁶Al states are erroneous. This paper reports on a reanalysis of spins, parities, and isospins for ²⁶Al states located at E_x<8.00 MeV. We deduce new stellar rates for the reaction ²⁵Mg(p,γ)²⁶Al and compare our results with previous values. Furthermore, shell-model calculations for the mass A=26 system are performed. Theoretical excitation energies, J^π values, γ-ray transition strengths, spectroscopic factors, and proton partial widths are compared to experimental data and new shell-model assignments of experimental states in ²⁶Al are derived. We estimate Coulomb displacement energies of excited ²⁶Mg and ²⁶Si mirror states and present new analog assignments for T=1 triplet states in A=26 nuclei. Based on shell-model results and analog state information we present updated stellar rates for the ²⁵Al(p,γ)²⁶Si reaction. © 1996 The American Physical Society.