Isovector and isoscalar spin-multipole giant resonances in the parent and daughter nuclei of double-β-decay triplets

The strength distributions, including giant resonances, of isovector and isoscalar spin-multipole transitions in the commonly studied double-β-decay triplets are computed in the framework of the quasiparticle random-phase approximation (QRPA) using the Bonn-A two-body interaction in no-core single-particle valence spaces. The studied nuclei include the double-β parent and daughter pairs (76Ge, 76Se), (82Se, 82Kr), (96Zr, 96Mo), (100Mo, 100Ru), (116Cd, 116Sn), (128Te, 128Xe), (130Te, 130Xe), and (136Xe, 136Ba). The studied transitions proceed from the ground states to the Jπ=0−,1−,2− (spin-dipole transitions) and Jπ=1+,2+,3+ (spin-quadrupole transitions) excited states in these nuclei. Comparison of the present results with potential future data may, indirectly, shed light on the reliability of QRPA-based nuclear-structure frameworks in description of the wave functions of nuclear states relevant for the two-neutrino and neutrinoless double β decays in the studied triplets.