High-spin states of $^{70}$Ge and a role of g$_{9/2}$ orbit

High-spin states of $^{70}$Ge have been studied via the $^{60}$Ni($^{12}$C, 2$p \gamma$)$^{70}$Ge reaction at 45 MeV. The ground-state band and the second 0$^{+}$ band have been extended to the 12$^{+}$ and 8$^{+}$ states, respectively. Two negative-parity bands, one of which has a coupled strucure and the other has a decoupled structure, have been observed. Although the decoupled one was known previously up to the (21-) state, the order of $E$2 transitons up to the 15$^{-}$ state have been largely modified by this experiment. The particle alignment observed in the ground-state band has been compared with those for the neighboring even Ge isotopes. The experimental level scheme has been compared with the shell model calculations in the model space ($2p_{3/2}$, $1f_{5/2}$, $2p_{1/2}$,$1g_{9/2}$) employing the two kinds of effective interactions, one of which is an extended $P+QQ$ and the other is developed from a renormalized G-matrix.