2K(2ν)-Capture in Xe-124: Results of Data Processing for an Exposure of 37.7 kg x day

Abstract

The results of the experimental search for two-neutrino $2K$-capture in ${}^{124}$Xe with a large copper proportional counter obtained by processing the data for an exposure of 37.7 kg$\times$day are presented. The experimental setup is located at the Underground Low-Background Laboratory of the Baksan Neutrino Observatory at a depth of 4900 m w.e. The combination of methods of selection of useful signals with a unique set of characteristics and the event topology taken into account allowed us to suppress the background in the energy region of interest. A new half-life limit for $2K(2\nu )$-capture in ${}^{124}$Xe was determined: T${}_{1/2}\ge 7.7\cdot 10^{21}$ yrs (90\% C.L.).

5 pages, 4 figures; to be published in PEPAN