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

Existing experimental proton stripping reaction data on Mg-25 leading to threshold states in Al-26 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, gamma) work. It is also shown that several of the unique J(pi) values assigned previously to Al-26 states are erroneous. This paper reports on a reanalysis of spins, parities, and isospins for Al-26 states located at E(x)<8.00 MeV. We deduce new stellar rates for the reaction Mg-25(p,gamma)Al-26 and compare our results with previous values. Furthermore, shell-model calculations for the mass A = 26 system are performed. Theoretical excitation energies, J(pi) values, gamma-ray transition strengths, spectroscopic factors, and proton partial widths are compared to experimental data and new shell-model assignments of experimental states in Al-26 are derived. We estimate Coulomb displacement energies of excited Mg-26 and Si-26 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 Al-25(p, gamma)Si-26 reaction.