Lifetime measurements and collective behavior inV49

Abstract

Lifetimes of levels in $^{49}\mathrm{V}$ have been measured using the Doppler-shift attenuation method. States were populated with the $^{46}\mathrm{Ti}(\ensuremath{\alpha},p)^{49}\mathrm{V}$ reaction at a beam energy of 10 MeV. Protons were detected near 180\ifmmode^\circ\else\textdegree\fi{} relative to the beam and most Doppler shifts were measured between $\ensuremath{\gamma}$ spectra accumulated at ${\ensuremath{\theta}}_{\ensuremath{\gamma}}=53 \mathrm{and} 140\ifmmode^\circ\else\textdegree\fi{}$. Values or limits were obtained for the mean lifetimes of 25 levels in $^{49}\mathrm{V}$ from 748 to 2812 keV in excitation energy. The positive parity levels appear to form two rotational bands with ${K}^{\ensuremath{\pi}}={\frac{3}{2}}^{+} \mathrm{and} {\frac{1}{2}}^{+}$. The first 2 MeV of the negative parity level scheme is reproduced rather well with calculations using the strong coupling model. This model also predicts the transition strengths reasonably well. These results suggest strong collective behavior in the states of both parities.NUCLEAR REACTIONS $^{46}\mathrm{Ti}(\ensuremath{\alpha},p\ensuremath{\gamma})$, ${E}_{\ensuremath{\gamma}}=10$ MeV; measured Doppler-shift attenuation. $^{49}\mathrm{V}$ deduced levels, $\ensuremath{\tau}$, $J$, $\ensuremath{\pi}$, $B(\ensuremath{\Lambda})$, branching ratios. Enriched target.