Shape coexistence and tilted-axis rotation in neutron-rich hafnium isotopes

We have performed tilted-axis-cranked Hartree-Fock-Bogoliubov calculations for a neutron-rich hafnium isotope ($^{182}$Hf) whose proton and neutron numbers are both in the upper shell region. We study whether the shell effects play a role in producing high-$K$ isomers or highly gamma-deformed states at high spin. In particular, the possibility of shape coexistence and the effect of wobbling motion are discussed.Comment: 4 pages, 3 figures, to be published in Phys. Lett.

K-hindered decay of a six-quasiparticle isomer in Hf176

The structure and decay properties of high-K isomers in Hf176 have been studied using beam sweeping techniques and the Gammasphere multidetector array. A new ΔK=8 decay branch, from a Kπ=22⊃-, six-quasiparticle, isomeric (t1/2=43μs) state at 4864 keV to the 20⊃- state of a Kπ=14⊃- band, has been identified. The reduced hindrance factor per degree of K forbiddenness for this decay is measured to be unusually low (fν=3.2), which suggests K mixing in the states involved. The deduced interaction matrix elements are discussed within the context of relevant K-mixing scenarios. The 3266-keV state, previously interpreted as a Kπ=16⊃+ intrinsic state, is reassigned as the Jπ=16⊃+ member of the band based on the Kπ=15⊃+ state at 3080 keV. The systematics of fν values as a function of the degree of forbiddenness is discussed in light of this change

The 1,3-Diazabiphenylene system. synthesis, chemistry, and incorporation into a linearly extended purine analogue

117 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.The first synthesis of the 1,3-diazabiphenylene ring system by cobalt-catalyzed cooligomerization of a novel diethynylpyrimidine and bis(trimethylsilyl)acetylene is described. This diazabiphenylene is found to undergo an unusual structural rearrangement on treatment with acid in methanol, providing a substituted isoquinoline. Progress toward the synthesis of the dimensional probe, lin-bcb-adenine, incorporating the 1,3-diazabiphenylene skeleton, is summarized, and the synthesis of a pyrimido{6,5-i}imidazo{4,5-g}cinnoline, via a heteroaromatic cross coupling reaction, is discussed.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Identification of a High-K Isomer in Neutron-Rich 185^185Ta

A ${t}_{1/2}{>}{1}$ ms, high-$K$ isomeric state feeding a strongly coupled rotational band has been identified following the deep inelastic reaction $^{238}_{\phantom{1}92}$U + $^{186}_{\phantom{1}74}$W at 1600 MeV. Examination of ${\gamma}$-ray and X-ray data combined with a g-factor analysis derived from in-band branching ratios suggests the assignment of the new states to the neutron-rich nucleus $^{185}_{\phantom{1}73}$Ta