I. K. Shestakova

Extending the region of triaxial superdeformation: Candidate TSD bands in 174Hf

Abstract Three, possibly four, regularly spaced rotational bands with large dynamic moments of inertia have been identified in 174 Hf. Their properties are consistent with known triaxial superdeformed bands of the Lu/Hf region. Calculations predict substantial triaxial deformation ( γ ≈±17°) for 174 Hf structures with deformation ϵ 2 ≈0.45, despite the fact that 174 Hf is eight neutrons away from the previously established N =94 triaxial superdeformed gap. Shell gaps at N =100 and 106 with γ ⩾15° are predicted for ϵ 2 ≈0.45, and are most likely responsible for the calculated TSD minima in 174 Hf.

Harvesting new isomers in neutron-rich hafnium nuclei

P. Chowdhury”, I. Shestakova”, R. D’Alarcaoa, C.J. Pearsonb, Z. Podolyakb, P.M. Walkerb, C. Wheldonb, D.M. Cullenc, I. Ahmadd, M.P. Carpenterd, R.V.F. Janssensd, T.L. Khood, F.G. Kondevd, C.J. Listerd, D. Seweryniakd and I. Wiedenhoeverd aDepartment of Physics, University of Massachusetts, Lowell, MA 01854, USA bDepartment of Physics, University of Surrey, Guildford GU2 5XH, UK ‘Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, UK dArgonne Na tl ‘o nal Laboratory, Argonne, IL 60439, USA New multi-quasiparticle K-isomers have been investigated in neutron-rich hafnium nu- clei via inelastic and transfer reactions with a pulsed 238U beam on a lsoHf target. The emphasis of this presentation is on the specific techniques of isolating and characteriz- ing isomers with 2~s half-lives and low cross-sections in the transfer channels using the Gammasphere array. 1. THE PHYSICS Quantum numbers associated with special symmetries of the nuclear wave-function in- vite investigation regarding their limits of validity. One that has received considerable attention now for a number of years is K, the

Possible Triaxial Superdeformation in 174 Hf

Four regularly spaced rotational bands with large dynamical moments of inertia, which are consistent with known superdeformed bands in the Lu/Hf region, have been identified in 174Hf. The states were populated in the 130Te(48Ca,4n) reaction at a beam energy of 194 MeV. The Gammasphere array detected the emitted gamma radiation. Ultimate cranker calculations predict substantial triaxial deformation (γ ≈ ±17°) for highly deformed 174Hf structures. However, 174Hf is eight neutrons away from the previously established N = 94 triaxial superdeformed shell gap. Shell gaps at N = 100 and 106 with γ ⩾ 15° are observed when e2 ≈ 0.45, which may be responsible for the predicted TSD minima in 174Hf.