High-spin rotational bands and pairing reduction in 166Hf

Rotational properties of the 166Hf nucleus have been studied by in-beam spectroscopic methods using the 150Sm(20Ne, 4n)166Hf reaction. The ground band was observed up to the Isup(π)=18+ level, the s-band from the Isup(π)=12+ up to Isup(π)=22+ level; in addition two side bands were found. The results are interpreted in terms of the pairing-self-consistent Hartree-Fock-Bogolyubov cranking model. Quantitative agreement between theory and experiment is obtained for the crossing of the ground band and s-band. The calculations predict a reduction of about 50% in the neutron pairing energy gap of yrast states in the crossing region. The kinematical (phisup((1))) and dynamical (phisup((2))) moments of inertia are analysed. (orig.)