Triaxiality And The Wobbling Mode Of Strongly Deformed Nuclei

摘要

Triaxiality in nuclei influences many spectroscopic quantities related to the rotational band structure in deformed nuclei. Signature effects are expected in energies as well as in electromagnetic properties. Yet such effects may also arise as a result of the interplay of mechanisms not related to triaxiality. In contrast, the wobbling mode is uniquely related to triaxiality and introduces a series of bands with increasing wobbling phonon number, n_w. The pattern of γ-transitions between the wobbling excitations will be influenced by the presence of an aligned particle. Recently, evidence for the wobbling mode was obtained, and even a two-phonon wobbling excitation has now been identified in ~(163)Lu. The similarity between the data in ~(163)Lu and newly established bands and connecting transitions in the neighbouring nuclei, ~(165)Lu and ~(167)Lu, indicates that wobbling may be a more general phenomenon in this region. The higher phonon wobbling description shows some anharmonicity, but the characteristic large Δn_w= 1 E2 strength is observed The wobbling interpretation is based on comparison to particle-rotor calculations in which an i_(13/2) proton is coupled to a biaxial core.