title: Ultra-low gamma-ray measurement system for neutrinoless double beta decay.
abstract: An experiment for the detection of 0νβ(+)/EC and 0νEC/EC in 92Mo nuclei has been carried out with a scintillating crystal, CaMoO4, in coincidence with the HPGe detector. We study the background events inside the event selection window for 0ν β(+)/EC decays of CaMoO4 detector. For 51.2 days of data taking period, we didn't observe any event in the neutrinoless EC/EC decay event window. The (92)Mo 0νβ(+)/EC decay half-life limit was set to 0.61×10(20) years with a 90% confidence by method of Feldman and Cousins. This ultra-low gamma ray measurement utilizing coincidence technique can be used for the resonant EC/EC decay process of some nuclei which is potentially important for neutrinoless double beta decay process.
authors.affiliation: Physics Department, Sejong University, Seoul 143-747, South Korea. wgkang@sju.ac.kr
authors.forename: W G
authors.initials: WG
authors.lastname: Kang
authors.forename: J H
authors.initials: JH
authors.lastname: Choi
authors.forename: E J
authors.initials: EJ
authors.lastname: Jeon
authors.forename: J I
authors.initials: JI
authors.lastname: Lee
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.forename: S K
authors.initials: SK
authors.lastname: Kim
authors.forename: Y D
authors.initials: YD
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: K J
authors.initials: KJ
authors.lastname: Ma
authors.forename: S S
authors.initials: SS
authors.lastname: Myung
authors.forename: J H
authors.initials: JH
authors.lastname: So
mesh_terms: D001610:Beta Particles; D004601:Elementary Particles; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005720:Gamma Rays; D006207:Half-Life; D007554:Isotopes / Q000032:analysis*; D008982:Molybdenum / Q000032:analysis*; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D013051:Spectrometry, Gamma / Q000295:instrumentation*
chemical_list: D007554:Isotopes; D008982:Molybdenum
keywords: (92)Mo; 0νβ(+)/EC; Neutrinoless double beta decay