The Kπ = 0+ bands of 178Hf and the allowed unhindered beta transformations of 9.3 min 178Ta and 22 d 178W

The decay of 22 d 178W and 9.3 min 178Ta (1+) has been investigated by means of direct and coincidence spectrometry with Ge(Li) and scintillation detectors. The Q-value of the electron-capture decay of 178W was determined to be 89±2 keV from the K-capture-to-total capture ratio. The corresponding log ft value is 4.65. The ground-state-to-ground-state beta decay rates were analysed in light of the pair correlation scheme. Capture-to-positon ratios were deduced for 178Ta and found to agree with theory. Excited states in 178Hf (characterized by their energy in keV, spin and parity) were established at 1199(0+), 1276(2+), 1434(0+), 1444(0+), 1496(2+), 1514(2+, 1+ or 1−) and 1561(2+). The 1199 keV state is interpreted as a beta vibration, the 1434 and 1444 keV 0+ states contain probably large amplitudes of the View the MathML source [514] neutron pair of the View the MathML source[514] proton pair (labelled by Nilsson quantum numbers View the MathML source. Energies and beta decay rates for the 0+ states are compared with the calculations of Soloviev. The energy of the third excited 0+ state is found to be much lower than this theory predicts. The first excited Kπ = 0+ band is less strongly fed in beta decay than the calculations predict.