Level structure ofSe70

The level structure of ${}_{}{}^{70}{}_{}{}^{}\mathrm{Se}$ was studied via the ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$,$\mathrm{pn}$)${}_{}{}^{70}{}_{}{}^{}\mathrm{Se}$ reaction at a beam energy of 38 MeV. Measurements were made of $\gamma$-ray singles and $\gamma -\gamma$ coincidence spectra, $\gamma$-ray angular distributions, and $\gamma -\gamma$ directional correlations. Level energies, decay modes, spins and parities, $\gamma$-ray mixing ratios, and $\gamma$-ray branching ratios were deduced. The levels in the yrast band through $8^{+}$, a tentative second ($0^{+}$) state at 2011.2 keV, and a $3^{-}$ state at 2519.2 keV are some of the new results obtained from the present investigation. The moment-of-inertia plot shows a break around $6^{+}$ for the yrast levels, which is attributed to band crossing. Interacting boson approximation calculations were performed and are compared with the experimental values for the energy levels.