The properties of excited states in the neutron-rich nucleus 194 Os have been investigated using the 192 Os( 18 O , 16 O) 194 Os reaction with an 80 MeV beam provided by the IFIN-HH Laboratory, Bucharest. Discrete γ -ray decays from excited states have been measured using the hybrid HPGe-LaBr 3 (Ce) array RoSPHERE. The current work identifies a number of previously unreported low-lying nonyrast states in 194 Os as well as the first measurement of the half-life of the yrast 2 + state of 302( 50) ps. This is equivalent to a B(E2 : 2 + → 0 + ) = 45( 16) W.u. and intrinsic quadrupole deformation of β eff = 0.14(1). The experimental results are compared with Hartree-Fock-Bogoliubov-interacting-boson-model calculations and are consistent with a reduction in a quadrupole collectivity in Os isotopes with increasing neutron number.

Using a hybrid Gammasphere array coupled to 25 LaBr 3 (Ce) detectors, the lifetimes of the first three levels of the yrast band in 114 Pd, populated via 252 Cf decay, have been measured. The measured lifetimes are τ 2 + = 103(10) ps, τ 4 + = 22(13) ps, and τ 6 + 10 ps for the 2 + 1 , 4 + 1 , and 6 + 1 levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E 2; J → J − 2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio R B(E 2) = B(E 2; 4 + 1 → 2 + 1)/B(E 2; 2 + 1 → 0 + 1) = 0.80(42) is measured for the first time in 114 Pd and compared with the known values R B(E 2) in the palladium isotopic chain: the systematics suggest that, for N = 68, a transition from γ-unstable to a more rigid γ-deformed nuclear shape occurs.

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Mean lifetimes of yrast states of the isotopes 174,176,178,180 Hf have been measured using fastelectronic scintillation timing. Excited states of 174,176,178 Hf were populated via β decay, while 180 Hf was populated via Coulomb excitation. The lifetimes of the 2 + 1 and 4 + 1 states of all isotopes and the lifetimes of the 6 + 1 states of 174,178 Hf were measured, using the slope and the centroid shift methods. The mean lifetime, τ (4 + 1) = 85(13) ps, of 178 Hf has been determined for the first time. In addition, the mean lifetimes of the 2 − 1 and the 3 − 1 states of 176 Hf have been determined. Systematic uncertainties on the evolution of data as a function of neutron number were reduced by using the same setup for all the isotopes of interest. The data are in agreement with other recent lifetime measurements where available and shows a shift of the maximum of collectivity for the Hf isotopic chain from neutron mid-shell at N=104 to N=100.