ISOSPIN-FORBIDDEN COMPOUND NUCLEAR RESONANCES IN 25AL AND 29P

The analogs of the ground state and first excited state of Na25 and Al29 have been studied as compound resonances in Al25 and P29, respectively, formed by scattering protons from Mg24 and Si28 targets. The accurate excitation energies obtained for these resonances, which are in excellent agreement with their locations available from delayed-proton, (p, t), and (p,) experiments, were used to predict the masses of Si25 and S29 from the isobaric-multiplet mass formula, and to calculate Coulomb-energy differences between the members of these isospin quartets. Total widths (<300 eV) and partial proton widths were extracted for the sharp isospin-forbidden T=32 resonances and compared with the widths of several new T=12 resonances in Al25 and P29 lying in the same region of excitation (7.5 to 10.0 MeV). Shifts are observed between the locations of corresponding analog states in the parent and Tz=-12 nuclei. © 1969 The American Physical Society.