Improved limits on $β^+$EC and ECEC processes in $^{74}$Se

A. S. Barabash; V. B. Brudanin; A. A. Klimenko; S. I. Konovalov; A. V. Rakhimov; E. N. Rukhadze; N. I. Rukhadze; Yu. A. Shitov; I. Stekl; G. Warot; V. I. Umatov

doi:10.1016/j.nuclphysa.2020.121697

arXiv · 2001.07069

Improved limits on $β^+$EC and ECEC processes in $^{74}$Se

A. S. Barabash·V. B. Brudanin·A. A. Klimenko·S. I. Konovalov·A. V. Rakhimov·E. N. Rukhadze·N. I. Rukhadze·Yu. A. Shitov·I. Stekl·G. Warot·V. I. Umatov

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Abstract

New limits on $β^+$EC and ECEC processes in $^{74}$Se have been obtained using a 600 cm$^3$ HPGe detector and an external source consisting of 1600 g of a natural selenium powder. For different $β^+$EC and ECEC transitions (to the ground and excited states) obtained limits are on the level $\sim (0.2-4.8)\times10^{19}$ yr at 90\% C.L. In particular, for the potentially resonant transition into the 1204.2 keV excited state of $^{74}$Ge a lower half-life limit of $1.1\times10^{19}$ yr at 90\% C.L. has been obtained. Possibility to increase the sensitivity of such measurements is discussed.

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A. S. Barabash, V. B. Brudanin, A. A. Klimenko, S. I. Konovalov, A. V. Rakhimov, E. N. Rukhadze, N. I. Rukhadze, Yu. A. Shitov, I. Stekl, G. Warot, V. I. Umatov. 2020-01-20. Improved limits on $β^+$EC and ECEC processes in $^{74}$Se. https://doi.org/10.1016/j.nuclphysa.2020.121697

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