Collective behavior in $^{71}$As

High-spin states in $^{71}$As were studied using the $^{54}$Fe($^{23}$Na, $\alpha 2 p$) reaction at 80 MeV provided by the John D. Fox superconducting accelerator at Florida State University. Prompt $\gamma$-$\gamma$ coincidences were measured using an array of 10 Compton-suppressed Ge detectors. The yrast band based on the $\pi g_{9/2}$ intrinsic configuration was extended up to a $(\frac{37}{2}^+)$ state and now shows evidence of a band crossing near $\hbar \omega = 0.7$ MeV. Lifetimes of 17 excited states were measured using the Doppler-shift attenuation method applied to the experimental line shapes of decays in three known rotational bands. Transition quadrupole moments $Q_t$ inferred from the lifetimes indicate that moderate to high collective behavior persists to the highest observed spins in the lowest positive- and negative-parity bands. The band suggested to be based on the $\pi f_{7/2}$ orbital shows similar collectivity and large intraband $B(M1)$ strengths, but the associated $Q_t$ values are somewhat smaller than expected from cranked Woods-Saxon calculations. These results will also be compared with the predictions of the projected shell model.