Using a hybrid Gammasphere array coupled to 25 ${\mathrm{LaBr}}_3\left(\text{Ce}\right)$ detectors, the lifetimes of the first three levels of the yrast band in ${}^{114}\mathrm{Pd}$, populated via ${}^{252}\mathrm{Cf}$ decay, have been measured. The measured lifetimes are ${\tau }_{2^{+}}=103\left(10\right)\mathrm{ps}, {\tau }_{4^{+}}=22\left(13\right)\mathrm{ps}$, and ${\tau }_{6^{+}}\le 10\mathrm{ps}$ for the $2_1^{+}, 4_1^{+}$, and $6_1^{+}$ levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities $B(E2;J\to J-2)$ are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio $R_{B\left(E2\right)}=B(E2;4_1^{+}\to 2_1^{+})/B(E2;2_1^{+}\to 0_1^{+})=0.80\left(42\right)$ is measured for the first time in ${}^{114}\mathrm{Pd}$ and compared with the known values $R_{B\left(E2\right)}$ in the palladium isotopic chain: the systematics suggest that, for $N=68$, a transition from $\gamma$-unstable to a more rigid $\gamma$-deformed nuclear shape occurs.

• Received 29 June 2019
• Revised 31 August 2019

DOI:https://doi.org/10.1103/PhysRevC.100.044309