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 48 Ca , 116 Cd (p, n) and the 48 Ti , 116 Sn (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.