Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userHigh-precision measurement of the half-life of $^{62}$Ga
274
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The beta-decay half-life of 62Ga has been studied with high precision using on-line mass separated samples. The decay of 62Ga which is dominated by a 0+ to 0+ transition to the ground state of 62Zn yields a half-life of T_{1/2} = 116.19(4) ms. This result is more precise than any previous measurement by about a factor of four or more. The present value is in agreement with older literature values, but slightly disagrees with a recent measurement. We determine an error weighted average value of all experimental half-lives of 116.18(4) ms.
rate research
Read More
The half-life of $^{19}$Ne has been measured using a real-time digital multiparametric acquisition system providing an accurate time-stamp and relevant information on the detectors signals for each decay event. An exhaustive offline analysis of the data gave unique access to experimental effects potentially biasing the measurement. After establishing the influence factors impacting the measurement such as after-pulses, pile-up, gain and base line fluctuations, their effects were accurately estimated and the event selection optimized. The resulting half-life, $17.2569pm0.0019_{(stat)}pm0.0009_{(syst)}$~s, is the most precise up to now for $^{19}$Ne. It is found in agreement with two recent precise measurements and not consistent with the most recent one [L.J. Broussard {it et al.}, Phys. Rev. Lett. {bf112}, 212301 (2014)] by 3.0 standard deviations. The full potential of the technique for nuclei with half-lives of a few seconds is discussed.
A high-precision half-life measurement for the superallowed Fermi $beta^+$ emitter $^{22}$Mg was performed at the TRIUMF-ISAC facility using a 4$pi$ proportional gas counter. The result of $T_{1/2} = 3.87400 pm 0.00079$ s is a factor of 3 more precise than the previously adopted world average and resolves a discrepancy between the two previously published $^{22}$Mg half-life measurements.
A high-precision branching ratio measurement for the superallowed Fermi $beta^{+}$ emitter $^{62}$Ga was performed with the Gamma-Ray Infrastructure for Fundamental Investigations of Nuclei (GRIFFIN) spectrometer at the Isotope Separator and Accelerator (ISAC) radioactive ion beam facility at TRIUMF. The high efficiency of the GRIFFIN spectrometer allowed 63 $gamma$-ray transitions, with intensities down to $approx$1 part per million (ppm) per $^{62}$Ga $beta^{+}$ decay, to be placed in the level scheme of the daughter nucleus $^{62}$Zn, establishing the superallowed $beta$ branching ratio for $^{62}$Ga decay to be 99.8577$^{+0.0023}_{-0.0029}%$, a factor of 4 more precise than the previous world average. For several cascades, $gamma-gamma$ angular correlation measurements were performed to assign spins and/or determine the mixing ratios of transitions. In particular, the spin of the 2.342 MeV excited state in the daughter nucleus $^{62}$Zn was definitively assigned as $J = 0$. This assignment resolves a discrepancy between previous measurements and has important implications for the isospin symmetry breaking correction, $delta_{C1}$, in $^{62}$Ga superallowed Fermi $beta$ decay.
We report a precise determination of the 19Ne half-life to be $T_{1/2} = 17.262 pm 0.007$ s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current Standard Model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.
The half-life of tsups{37}K has been measured to be $1.23651(94)~mathrm{s}$, a value nearly an order of magnitude more precise than the best previously reported. The $beta^+$ decay of tsups{37}K occurs mainly via a superallowed branch to the ground-state of its $T=1/2$ mirror, tsups{37}Ar. This transition has been used recently, together with similar transitions from four other nuclei, as an alternative test of CVC and method for determining $V_{ud}$, but the precision of its $ft$ value was limited by the relatively large half-life uncertainty. Our result corrects that situation. Another motivation for improving the $ft$ value was to determine the standard-model prediction for the $beta$-decay correlation parameters, which will be compared to those currently being measured by the trinat{} collaboration at triumf. The new $ft$ value, $4605(8)~mathrm{s}$, is now limited in precision by the $97.99(14)%$ ground-state branching ratio.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
