Tidal waves in Pd102: A rotating condensate of multiple d bosons

Low-lying collective excitations in even-even vibrational and transitional nuclei may be described semiclassically as quadrupole running waves on the surface of the nucleus ("tidal waves"), and the observed vibrational-rotational behavior can be thought of as resulting from a rotating condensate of interacting d bosons. These concepts have been investigated by measuring lifetimes of the levels in the yrast band of the Pd102 nucleus with the Doppler shift attenuation method. The extracted B(E2) reduced transition probabilities for the yrast band display a monotonic increase with spin, in agreement with the interpretation based on rotation-induced condensation of aligned d bosons

In-beam spectroscopy of medium- and high-spin states in Ce 133

Medium and high-spin states in Ce133 were investigated using the Cd116(Ne22, 5n) reaction and the Gammasphere array. The level scheme was extended up to an excitation energy of ∼22.8 MeV and spin 93/2. Eleven bands of quadrupole transitions and two new dipole bands are identified. The connections to low-lying states of the previously known, high-spin triaxial bands were firmly established, thus fixing the excitation energy and, in many cases, the spin parity of the levels. Based on comparisons with cranked Nilsson-Strutinsky calculations and tilted axis cranking covariant density functional theory, it is shown that all observed bands are characterized by pronounced triaxiality. Competing multiquasiparticle configurations are found to contribute to a rich variety of collective phenomena in this nucleus

Effect of ground-state deformation on isoscalar giant resonances in Si 28

Multipole strength distributions for isoscalar L 642 transitions in Si28 have been extracted using 386-MeV inelastic \u3b1 scattering at extremely forward angles, including 0. Observed strength distributions are in good agreement with microscopic calculations for an oblate-deformed ground state. In particular, a large peak at an excitation energy of 17.7 MeV in the isoscalar giant monopole resonance strength is consistent with the calculations

Persistence of collective behavior at high spin in the N=88 nucleus Tb 153

Excited states in the N=88 nucleus Tb153 were observed up to spin ∼40 in an experiment utilizing the Gammasphere array. The Tb153 states were populated in a weak α4n evaporation channel of the Cl37 + Sn124 reaction. Two previously known sequences were extended to higher spins, and a new decoupled structure was identified. The πh11/2 band was observed in the spin region where other N=88 isotopes exhibit effects of prolate to oblate shape changes leading to band termination along the yrast line, whereas Tb153 displays a persistent collective behavior. However, minor perturbations of the very highest state in both signatures of this h11/2 band are observed, which perhaps signal the start of the transition towards band termination

Nuclear structure towards N=40 Ca 60: In-Beam γ-ray spectroscopy of Ti 58,60

Excited states in the neutron-rich N=38, 36 nuclei Ti60 and Ti58 were populated in nucleon-removal reactions from V61 projectiles at 90MeV/nucleon. The γ-ray transitions from such states in these Ti isotopes were detected with the advanced γ-ray tracking array GRETINA and were corrected event by event for large Doppler shifts (v/c∼0.4) using the γ-ray interaction points deduced from online signal decomposition. The new data indicate that a steep decrease in quadrupole collectivity occurs when moving from neutron-rich N=36, 38 Fe and Cr toward the Ti and Ca isotones. In fact, Ti58,60 provide some of the most neutron-rich benchmarks accessible today for calculations attempting to determine the structure of the potentially doubly magic nucleus Ca60

Transverse wobbling in Pr 135

A pair of transverse wobbling bands is observed in the nucleus Pr135. The wobbling is characterized by ΔI=1, E2 transitions between the bands, and a decrease in the wobbling energy confirms its transverse nature. Additionally, a transition from transverse wobbling to a three-quasiparticle band comprised of strong magnetic dipole transitions is observed. These observations conform well to results from calculations with the tilted axis cranking model and the quasiparticle rotor model