Excited states of the nucleus ${}^{79}\mathrm{Br}$ were investigated via the reaction ${}^{76}\mathrm{Ge}{(}^7\mathrm{Li},4n)$ at a beam energy of 35 MeV. Coincidence data of emitted γ rays were measured with an arrangement of six EUROBALL CLUSTER detectors. The $E2\mathrm{}$ bands built on the ${9/2}^{+}$ and ${3/2}^{-}$ states were extended up to $J=37/2\mathrm{}$ at $E\approx 8.8\hspace{0.5em}\mathrm{MeV}.$ The $M1\mathrm{}$ band starting with a ${15/2}^{-}$ state at 2.6 MeV was observed up to $J=(29/2)\mathrm{}$ at $E=6.4\mathrm{}\hspace{0.5em}\mathrm{MeV}.$ Crossover $E2\mathrm{}$ transitions within this band were observed for the first time. Mean lifetimes of 17 levels were deduced using the Doppler-shift-attenuation method. The $M1\mathrm{}$ band can be described within the tilted-axis-cranking model on the basis of the tilted three-quasiparticle configuration $\pi {(g}_{9/2}\left)\hspace{0.5em}\nu {(g}_{9/2}\right)\hspace{0.5em}\nu \mathrm{}\left(\mathrm{fp}\right)\mathrm{}$ which has a triaxial shape. This band appears as a mixed case including contributions of both magnetic and collective rotation.

• Received 17 January 2002

DOI:https://doi.org/10.1103/PhysRevC.65.044326