# A new investigation of half-lives for the decay modes of $^{50}$V

## TL;DR

This study measures the half-life of a rare decay mode of $^{50}$V with high precision and sets new lower limits, advancing understanding of its decay properties and testing theoretical models.

## Contribution

It provides the most precise measurement of the electron capture half-life and establishes a new lower limit for the $eta$-decay, improving previous constraints.

## Key findings

- Half-life for electron capture measured as 2.67 x 10^{17} yr.
- Lower limit for $eta$-decay set at 1.9 x 10^{19} yr.
- Measurement sensitivity aligns with theoretical predictions.

## Abstract

A new search for the decay modes of the 4-fold forbidden non-unique decay of $^{50}$V has been performed at the Gran Sasso Underground Laboratory (LNGS). In total an exposure of 197 kg $\times$ d has been accumulated. The half-life for the electron capture into the first excited state of $^{50}$Ti has been measured with the highest precision to date as $2.67_{-0.18}^{+0.16} \times 10^{17}$ yr (68% C.I.) in which systematics uncertainties dominate. The search for the $\beta$-decay into the first excited state of $^{50}$Cr resulted in a lower limit of ${1.9} \times 10^{19}$ yr (90% C.I.), which is an improvement of almost one order of magnitude compared to existing results. The sensitivity of the new measurement is now in the region of theoretical predictions.