Nuclear shapes of highly deformed bands in Hf171,172 and neighboring Hf isotopes

A Gammasphere experiment was carried out to search for triaxial strongly deformed (TSD) structures in Hf171,172 and the wobbling mode, a unique signature of nuclei with stable triaxiality. Three strongly deformed bands in Hf172 and one in Hf171 were identified through Ca48(Te128, xn) reactions. Linking transitions were established for the band in Hf171 and, consequently, its excitation energies and spins (up to 111/2) were firmly established. However, none of the Hf172 sequences were linked to known structures. Experimental evidence of triaxiality was not observed in these bands. The new bands are compared with other known strongly deformed bands in neighboring Hf isotopes. Theoretical investigations within various models have been performed. Cranking calculations with the Ultimate Cranker code suggest that the band in Hf171 and two previously proposed TSD candidates in Hf170 and Hf175 are built on proton (i13/2h9/2) configurations, associated with near-prolate shapes and deformations enhanced with respect to the normal deformed bands. Cranked relativistic mean-field calculations suggest that band 2 in Hf175 has most likely a near-prolate superdeformed shape involving the πi13/2νj15/2 high-j intruder orbitals. It is quite likely that the bands in Hf172 are similar in character to this band

Collective rotation and vibration in neutron rich 180,182Hf nuclei

High spin states in neutron rich 180 Hf and 182Hf nuclei were populated through inelastic and transfer reactions with a 136Xe beam incident on a thin 180Hf target, and investigated using particle 3 coincidence techniques. New collective band structures were observed, and previously known rotational and vibrational bands in these nuclei were extended to higher angular momenta. No obvious nucleon alignment was observed in the ground state band of either nucleus up to hbar 0.43 MeV, a significant delay compared to lighter even even Hf isotopes. Woods Saxon cranking calculations were performed to predict the nature of the first band crossings and shape evolution in 180,182H

Collective rotation and vibration in neutron-rich Hf-180,Hf-182 nuclei

High-spin states in neutron-rich Hf-180 and Hf-182 nuclei were populated through inelastic and transfer reactions with a Xe-136 beam incident on a thin Hf-180 target, and investigated using particle-gamma coincidence techniques. New collective band structures were observed, and previously known rotational and vibrational bands in these nuclei were extended to higher angular momenta. No obvious nucleon alignment was observed in the ground state band of either nucleus up to h omega=0.43 MeV, a significant delay compared to lighter even-even Hf isotopes. Woods-Saxon cranking calculations were performed to predict the nature of the first band crossings and shape evolution in Hf-180,Hf-182

Collective rotation and vibration in neutron-rich Hf-180,Hf-182 nuclei

High-spin states in neutron-rich Hf-180 and Hf-182 nuclei were populated through inelastic and transfer reactions with a Xe-136 beam incident on a thin Hf-180 target, and investigated using particle-gamma coincidence techniques. New collective band structures were observed, and previously known rotational and vibrational bands in these nuclei were extended to higher angular momenta. No obvious nucleon alignment was observed in the ground state band of either nucleus up to h omega=0.43 MeV, a significant delay compared to lighter even-even Hf isotopes. Woods-Saxon cranking calculations were performed to predict the nature of the first band crossings and shape evolution in Hf-180,Hf-182.</p

Collective rotation and vibration in neutron-rich ^180,182Hf nuclei

High-spin states in neutron-rich Hf-180 and Hf-182 nuclei were populated through inelastic and transfer reactions with a Xe-136 beam incident on a thin Hf-180 target, and investigated using particle-gamma coincidence techniques. New collective band structures were observed, and previously known rotational and vibrational bands in these nuclei were extended to higher angular momenta. No obvious nucleon alignment was observed in the ground state band of either nucleus up to h omega=0.43 MeV, a significant delay compared to lighter even-even Hf isotopes. Woods-Saxon cranking calculations were performed to predict the nature of the first band crossings and shape evolution in Hf-180,Hf-182.</p