Investigation of negative-parity states in Dy156 : Search for evidence of tetrahedral symmetry

Abstract

An experiment populating low/medium-spin states in Dy156 was performed to investigate the possibility of tetrahedral symmetry in this nucleus. In particular, focus was placed on the low-spin, negative-parity states since recent theoretical studies suggest that these may be good candidates for this high-rank symmetry. The states were produced in the Nd148(C12,4n) reaction and the Gammasphere array was utilized to detect the emitted γ rays. B(E2)/B(E1) ratios of transition probabilities from the low-spin, negative-parity bands were determined and used to interpret whether these structures are best associated with tetrahedral symmetry or, as previously assigned, to octupole vibrations. In addition, several other negative-parity structures were observed to higher spin and two new sequences were established.Received 7 July 2016DOI:https://doi.org/10.1103/PhysRevC.95.014321©2017 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCollective levelsElectromagnetic transitionsLow & intermediate energy heavy-ion reactionsProperties150 ≤ A ≤ 189TechniquesCollective modelsNuclear Physics