Spectroscopy of Neutron-rich $^{248-250}$Cf Nuclei*

In continuation of our high-spin studies in neutron-rich $^{244-246}$Pu, $^{246-249}$Cm nuclei, using deep-inelastic and transfer reactions [1], we report on new spectroscopic information in the N = 150-152 nuclei $^{248-250}$Cf. High-spin states in $^{248-250}$Cf nuclei were populated using a $^{208}$Pb beam incident on a radioactive $^{249}$Cf target, with prompt gamma rays detected by the Gammasphere array. The ground state bands of $^{248}$Cf and $^{250}$Cf have been extended to high-spins and the K$^{\pi }$ = 2$^{-}$ octupole band in $^{248}$Cf has been observed for the first time. In addition to the previously observed ground-state bands of $^{249}$Cf [1], a new pair of bands built on a neutron single-particle orbital has been identified. The new data will be presented in the context of the extended systematics of this region and available theoretical predictions for the neutron-rich, transplutonium N $\ge $ 150 nuclei. Possible connections to non-axial octupole collective effects will be discussed. \\[4pt] [1] S. K. Tandel \textit{et al.}, Phys. Rev. C \textbf{82}, 041301(R) (2010)