GT± STRENGTH DISTRIBUTION IN 48Sc AND 116In MEASURED BY (p, n) AND (n, p) REACTIONS AT 300 MeV AND THEIR IMPLICATIONS FOR 2ν2β DECAY

Angular distributions of the double differential cross sections for the 48Ca, 116Cd(p, n) and the 48Ti, 116Sn(n, p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) transition strengths. In both (n, p) spectra beyond 8 MeV excitation energy extra B(GT+) strengths which are not predicted by either shell model or QRPA calculations. This extra B(GT+) strengths certainly contribute to the nuclear matrix element of the 2ν2β-decay.