β decay of 98Ag:: Evidence for the Gamow-Teller resonance near 100Sn -: art. no. 064315

In two complementary measurements, a cubelike array of six Euroball-Cluster germanium detectors and a total-absorption gamma spectrometer were used to investigate the beta decay of Ag-98, a three-proton-hole and one-neutron-particle nucleus with respect to the Sn-100 core. The half-life and Q(EC) value of the decay were determined to be 47.7(0.3) s and 8200(70) MeV, respectively. A total of 438 gamma rays (414 new) was observed, and 173 levels (163 new) in Pd-98 have been identified. The Gamow-Teller (GT) beta -decay strength distribution from the total-absorption gamma spectroscopy reveals a large GT resonance around 6 MeV with a width of about 2 MeV. The hindrance factor for the total GT strength, summed from the ground state up to 7.8 MeV excitation energy in Pd-98, amounts to 4.6(6) with reference to a shell-model calculation which yields good agreement with the shape of the experimental GT resonance.