An experiment populating low/medium-spin states in ${}^{156}\mathrm{Dy}$ 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 ${}^{148}\mathrm{Nd}({}^{12}\mathrm{C},4n)$ reaction and the Gammasphere array was utilized to detect the emitted $\gamma$ rays. $B\left(E2\right)/B\left(E1\right)$ 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 2016

DOI:https://doi.org/10.1103/PhysRevC.95.014321