Isospin- and Mirror-Symmetry Structures of Nuclei Studied through Weak, EM and Strong Interactions

Isospin symmetry structure of highly-excited states in mirror nuclei ²⁷Al and ²⁷Si having isospin T = 1/2 and T_z = ±1/2 has been studied by the comparison of strengths and energies of the M1 and Gamow-Teller (GT) transitions connected with the ground state (g.s.) of ²⁷Al. By analyzing the strengths of analogous M1 and GT transitions, isoscalar and orbital contributions in M1 transitions are discussed. The study of the symmetry structure further leads to the identification of the isospin of each pair of analogous excited-states based on the different sensitivity of the M1 and GT transitions to isospin transfers ΔT = 0 and 1.