Gamow-Teller resonance in β+ decay of sup(147m)Dy and spin-isospin current renormalization

The total absorption spectrum of γ-rays following β+ decay of sup(147m)Dy has been investigated. The decay energy Qsub(epsilon) = 7.18 (10) MeV and an improved value of half-life Tsub(1/2) = 55.7(7) s are determined. The intensity of the transitions from the isomeric state is 31 (3)%, the internal conversion being included. More than 40% of decays populate 147Tb levels with the excitation energy Esub(ex) >= 4.4 MeV. The β+ strength function Ssub(β)+ exhibits a pronounced narrow maximum at Esub(ex) = 4.84 MeV and some structure at higher energy. The total probability of sup(147m)Dy β+ decay corresponds to the value log ft = 3.67(8). The calculation of Ssub(β) carried out in the random-phase approximation gives the correct resonance energy. The coefficient of the spin-isospin current renormalization found from the comparison of the calculated β-decay probability with the experimental one is vertical strokeGsub(A)/gsub(v)vertical stroke = 0.7 +- 0.1. (orig.)