High-precision half-life determination of 14^{14}O via direct ββ counting

The half-life of the superallowed Fermi $\beta^+$ emitter $^{14}$O was determined to high precision via a direct $\beta$ counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, $T_{1/2}$($^{14}$O) = 70619.2(76) ms, is consistent with, but is more precise than, the world average obtained from 11 previous measurements. Combining the $^{14}$O half-life deduced in the present work with the previous most precise measurements of this quantity leads to a reduction in the overall uncertainty, by nearly a factor of 2. The new world average is $T_{1/2}$($^{14}$O) = 70619.6(63) ms with a reduced $\chi^2$ value of 0.87 obtained from 8 degrees of freedom

First Report of a Doublet 2209-keV State in 100^{100}Zr

International audienceA β-decay experiment aiming at investigation of the low-spin structure of 100Zr was performed using the GRIFFIN spectrometer at TRIUMFISAC. Based on the obtained data, a new 2 + state is postulated which is degenerate in energy with the established (5+) level at 2209 keV