High precision measurement of the Ne19β -decay half-life using real-time digital acquisition

Abstract

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, 17.2569 ± 0.0019 (stat) ± 0.0009 (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 et al., Phys. Rev. Lett. 112, 212301 (2014)] by 3.0 standard deviations. The full potential of the technique for nuclei with half-lives of a few seconds is discussed.

Precise branching ratio measurements in $^{19}$Ne beta decay and fundamental tests of the weak interaction

“…This is not unexpected, since the γ-ray measurement disagrees with the other three measurements and is more than 3σ away than the latest (and most precise) value published in Ref. [24]. The probability improves to 65% if we exclude the value from Ref.…”

“…Similar to our experiment, the authors of Refs. [23,24] used the method of β counting, while Broussard et al [25] determined the half-life using 511 keV annihilation radiation detected in two collinear HPGe detectors. A weighted mean of the four values yields a poor χ 2 probability of P (χ 2 , ν) ≈ 1%.…”

“…Since this discrepancy is yet to be resolved, for our subsequent analysis we choose to use an average value of T 1/2 = 17.257(2) s, obtained using only the results from Refs. [14,23,24] 6 . Together with the electron-capture branching fraction [29,33,34], the mass excesses from the most recent Atomic Mass Data Center compilation [35,36] and other small corrections [29] due to isospin symmetry breaking and radiative effects, we obtain a corrected f V t value for the 1/2 + → 1/2 + 19 Ne superallowed β decay to be…”

Decay microscope for trapped neon isotopes

“…Its singularly well-determined mixing ratio, makes 19 Ne the best candidate (along with 37 K) for determining V ud in mirror transitions. This fact motivated very precise measurements of the 19 Ne decay observables, namely its Q-value [91,92], half-life [93][94][95], and branching ratios [96,97]; as well as recent state of the art calculations of the relevant radiative and isospin-breaking corrections [98,99]. Calculating the beta-neutrino correlation coefficient from the mixing ratio, we arrive at a 19 = 0.0414 (15), having a 4% relative uncertainty.…”

Study of radioactivity built-up and decay with singles time-stamped data

“…Thus, this experimental data contain information about the radioactive decay of nuclei having (5) (0.65) 1 Absolute intensity per 100 decays. 2 From corresponding Zn isotopes via electron capture (EC)-decay 3 From 70 Ge via β − -decay half-lives ranging from minutes to days. The γ-rays emitted by the excited states of nuclei produced in-beam as well as through decay (Fig.…”