Eur. Phys. J. C (2023) 83: 930
https://doi.org/10.1140/epjc/s10052-023-12113-6

Regular Article – Experimental Physics

Application of the most frequent value method for ${}^{39}$Ar half-life determination

Canadian Nuclear Laboratories, 286 Plant Road, K0J 1J0, Chalk River, Ontario, Canada

^a Victor.Golovko@cnl.ca

Received: 20 July 2023
Accepted: 6 October 2023
Published online: 15 October 2023

Abstract

An evaluation method supported by robust statistical analysis was applied to historical measurements of ${}^{39}$Ar half-life. The method, based on the most frequent value (MFV) approach combined with bootstrap analysis, provides a more robust way to estimate ${}^{39}$Ar half-life, and results in $T_{1/2}($MFV$)=268.2_{-2.9}^{+3.1}$ years with uncertainty corresponding to the 68% confidence level. The uncertainty is a factor of 3 smaller than that of the most precise re-calculated ${}^{39}$Ar half-life measurements by Stoenner et al. and a factor of 2.7 smaller than that of the adopted half-life value in nuclear data sheets. Recently, the specific activity of the beta decay of ${}^{39}$Ar in atmospheric argon was measured in several underground facilities. Applying the MFV method to a specific activity of ${}^{39}$Ar from underground measurements results in $S{A}_{{}^{39}\text{Ar}/\text{Ar}}(\text{MFV})=0.{966}_{-0.018}^{+0.010}{\text{Bq/kg}}_{\text{atmAr}}$ with uncertainty corresponding to the 68% confidence level. In this paper the method to determine the half-life of ${}^{39}$Ar using the specific activity of ${}^{39}$Ar in atmospheric argon is also discussed.