Doppler-Shift Lifetime Measurement on the 2.79-MeV Level ofF19

Abstract

The mean lifetime of the 2.79-MeV level of ${\mathrm{F}}^{19}$ was determined by the Doppler-shift-attenuation method to be $\tau <1.9\mathrm{}\times {10}^{-13\mathrm{}}$ sec. This result and other lifetime data on the low-lying members of the ground-state rotational band are compared with the predictions of the rotational model both with and without band mixing due to particle-rotation coupling. The existing experimental data are consistent with both sets of calculated lifetimes.