beta decay of Ag-98: Evidence for the Gamow-Teller resonance near Sn-100 -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-p article nucleus with respect to the Sn-100 core. The half-life and Q(EC) va lue of the decay were determined to be 47.7(0.3) s and 8200(70) MeV, respec tively. A total of 438 gamma rays (414 new) was observed, and 173 levels (1 63 new) in Pd-98 have been identified. The Gamow-Teller (GT) beta -decay st rength 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 Me V excitation energy in Pd-98, amounts to 4.6(6) with reference to a shell-m odel calculation which yields good agreement with the shape of the experime ntal GT resonance.