Sum rules for double Gamow-Teller excitation

Sum rules are presented for the double Gamow-Teller excitation with ΔTz=±2. The sum rules consist of a model-independent term which is expressed by the numbers of protons and neutrons, and model-dependent terms. It is demonstrated by a numerical calculation that the model-independent term represents a good estimate of the double Gamow-Teller strength for nuclei with N≥Z+4. The calculation indicates that the strength is concentrated in lowest-isospin states, and a giant resonance is constructed near the double isobaric analog state. The double Gamow-Teller excitation favors an angular-momentum transfer of J=2 rather than J=0. (orig.)