Reinvestigation of octupole correlations in $^{146,147}$La

High spin states of neutron rich $^{146,147}$La have been reinvestigated by $\gamma$-$\gamma$-$\gamma$ and $\gamma$-$\gamma$-$\gamma$-$\gamma$ coincidence data from a $^{252}$Cf spontaneous fission experiment by using Gammasphere. Thirty-two new transitions and seventeen new levels in $^{146}$La are observed. Two new bands in $^{146}$La have been established. One of them is proposed to be the octupole parity partner of the previously known band. Twenty new transitions and thirteen new levels in $^{147}$La are observed. The ground state band of $^{147}$La has been established with a proposed 5/2$^+$ band-head. Angular correlations of cascades have been used to study the spins and parities of the states. The $B(E1)/B(E2)$ ratios between the proposed octupole bands in $^{146,147}$La have been measured showing decreasing octupole deformation from $^{144}$La to $^{146}$La, and from $^{145}$La to $^{147}$La. The backbending phenomenon of the four bands in $^{147}$La has been studied.