The mass region of rare-earth nuclei in the nuclear chart is riddled with well-deformed nuclei, exhibiting rotational properties and many interesting nuclear structure-related phenomena. The scarcity of experimental data as the neutron number increases and the exotic phenomena such as shape coexistence, which are strongly connected with the underlying symmetries of the Hamiltonian and are predicted to take place in this region, make this mass region a fertile ground for experimental and theoretical studies of nuclear structure. In this work, we investigate the structure of the even–even ^162–184Hf (hafnium) isotopes through a calculation of various observables such as $B(E2;0_1^{+}\to 2_1^{+})$ reduced transition matrix elements and quadrupole moments. Six different nuclear models are employed in the calculations of the observables for these nuclei, the shapes of which deviate from spherical symmetry, and as such, are characterized by Hamiltonians, which break the rotational invariance of the exact nuclear many-body Hamiltonian. The results of the present study are expected to establish some concrete guidelines for current and future experimental endeavors. Along these lines, the results for the ^162–180Hf isotopes are compared with existing experimental data where available, showing an overall good agreement.

The medium-to-heavy mass ytterbium isotopes (70Yb) in the rare-earth mass region are known to be well-deformed nuclei, which can be populated to very high spin, and are predicted to exhibit interesting phenomena, such as shape coexistence. The lack of any experimental information on the structure of the neutron-rich 180Yb isotope and the lifetime of the 21+ state of 178Yb have greatly motivated this study, which can offer useful information for the collective behavior of neutrons and protons in neutron-rich Yb isotopes. A measurement was performed to investigate the population of excited states and a first measurement of the unknown 21+ lifetime of 178Yb by means of a two neutron-transfer reaction 176Yb(18O,16O)178Yb at energies 68-74 MeV using the ROSPHERE array at IFIN-HH, Romania.

This work features preliminary results from a recent experimental campaign at IFIN-HH, Romania, aimed at measuring lifetimes of excited states in the neutron-rich 180Hf, by means of the RDDS technique. The 181Ta(11B,12C)180Hf proton pick-up reaction was used to populate excited states in the 180Hf nucleus. The ROSPHERE array loaded with 25 HPGe detectors was employed for the detection of the γ transitions depopulating the levels of interest. The array was coupled to the SORCERER particle detector and a plunger device enabling the study of p-γ and p-γ-γ coinciding events. Six different plunger foil distances were chosen, allowing for the construction of the decay curves of the observed γ transitions of interest, from which the corresponding level lifetimes can subsequently be deduced.

In the present work, a dedicated experimental study of the lifetimes of in Te and Sb isotopes was undertaken at the 9 MV Tandem accelerator at the IFIN-HH. Beams of 11B at 35 MeV impinged on a natAg target to populate the nuclei of interest and study their decay using the activation method. The emitted gamma rays and charged particles were detected by the ROSPHERE and SORCERER arrays. Lifetimes of the decaying isomeric and ground states in 117Te and 115,117Sb were measured. The present results update existing literature data from half a century ago employing a new reaction mechanism to populate the states of interest along with a more advanced array of detectors