Decay scheme of 50V

Abstract

Investigation of the ${}^{50}$V electron-capture to the $2^{+}$ 1553.8 keV level of ${}^{50}$Ti and search for $β^-$ decay of ${}^{50}$V to the $2^{+}$ 783.3 keV level of ${}^{50}$Cr (both those decays are fourfold forbidden with $\hat{I}”J^{\hat{I}”\ddot{I}€}=4^{+}$) have been performed using a vanadium sample of natural isotopic abundance with mass of 955 g. The measurements were conducted with the help of an ultra low-background HPGe-detector system located 225 m underground in the laboratory HADES (Belgium). The measured value of the half-life of ${}^{50}$V for electron capture was $T_{1/2}^{\mathrm{EC}}=(2.77_{-0.19}^{+0.20})\times 10^{17}$ yr. The $β^-$-decay branch was not detected and the corresponding lower bound of the half-life was $T_{1/2}^2\ge 8.9\times 10^{18}$ yr at the 90\% confidence level.

20 pages, 9 figures, 7 tables, 27 references