2K-Capture in 124Хе: Results of Data Processing for an Exposure of 37.7 kg day

Abstract

Abstract: The results of the experimental search for two-neutrino 2K-capture in 124Xe with a large copper proportional counter obtained by processing the data for an exposure of 37.7 kg 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(2ν)-capture in 124Xe was determined: T1/2 ≥ 7.7 × 1021 years (90% CL).