Rejection of randomly coinciding 2ν2β events in ZnMoO4 scintillating bolometers

• Published in: EPJ Web of conferences Vol. 65; p. 04002
• Main Authors: Chernyak D.M., Danevich F.A., Giuliani A., Mancuso M., Nones C., Olivieri E., Tenconi M., Tretyak V.I.
• Format: Journal Article
• Language: English
• Published: EDP Sciences 01.01.2014
• ISSN: 2100-014X
• DOI: 10.1051/epjconf/20136504002

Random coincidence of 2ν2β decay events could be one of the main sources of background for 0ν2β decay in cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, the mean-time and χ2 methods was applied to discriminate randomly coinciding 2ν2β events in ZnMoO4 cryogenic scintillating bolometers. The background can be effectively rejected on the level of 99% by the mean-time analysis of heat signals with the rise time about 14 ms and the signal-to-noise ratio 900, and on the level of 98% for the light signals with 3 ms rise time and signal-to-noise ratio of 30 (under a requirement to detect 95% of single events). Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed.