Spin‐isospin excitations from the ground‐state of ⁶⁴Ni

Spin‐isospin (Gamow‐Teller) excitations in ⁶⁴Cu and ⁶⁴Co have been studied using (³He,t) and (d,²He) charge‐exchange reactions on ⁶⁴Ni. As the isospin of the ⁶⁴Ni ground‐state is T₀=4, states with T=3, 4 and 5 in ⁶⁴Cu are excited via the (³He,t) reaction and states with T=5 in ⁶⁴Co via (d,²He). If we assume that the nuclear interaction is charge symmetric, the T=5 states in ⁶⁴Cu should appear at corresponding excitation energies (if corrected for the Coulomb displacement) and with similar strengths as the T=5 states in ⁶⁴Co. As in the ⁶⁴Cu spectrum the T=5 states are very weakly excited, only by combining the results of the two complementary experiments one can estimate the Gamow‐Teller strength starting from ⁶⁴Ni in a consistent way.