228 research outputs found
Searches for sterile neutrinos at the DANSS experiment
No full textDANSS is a highly segmented 1 m3 plastic scintillator detector. The DANSS detector is placed under an industrial 3.1 GWth reactor of the Kalinin Nuclear Power Plant 350 km NW from Moscow. The distance to the core is varied on-line from 10.7 m to 12.7 m. The reactor building provides about 50 m water-equivalent shielding against the cosmic background. DANSS detects almost 5000 νe per day at the closest position with the cosmic background less than 3%. The inverse beta decay process is used to detect νe. Sterile neutrinos are searched for assuming the 4ν model (3 active and 1 sterile ν). The exclusion area in the Δm142,sin22θ14 plane is obtained using a ratio of positron energy spectra collected at different distances. Therefore results do not depend on the shape and normalization of the reactor νe spectrum nor the detector efficiency. Results are based on 966 thousand antineutrino events collected at three different distances from the reactor core. The excluded area covers a wide range of the sterile neutrino parameters down to sin22θ14 < 0.01 in the most sensitive region
Search for Pauli exclusion principle violating atomic transitions and electron decay with a p-type point contact germanium detector
No full textA search for Pauli-exclusion-principle-violating K-alpha electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8x10^30 seconds at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the x-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8x10^30 seconds at 90 C.L. It is estimated that the MAJORANA DEMONSTRATOR, a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of 76-Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation. Abgrall, N; Arnquist, I J; Avignone, F T; Barabash, A S; Bertrand, F E; Bradley, A W; Brudanin, V; Busch, M; Buuck, M; Caldwell, A S; Chan, Y-D; Christofferson, C D; Chu, P -H; Cuesta, C; Detwiler, J A; Dunagan, C; Efremenko, Yu; Ejiri, H; Elliott, S R; Finnerty, P S; Galindo-Uribarri, A; Gilliss, T; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guinn, I S; Guiseppe, V E; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Jasinski, B R; Keeter, K J; Kidd, M F; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; MacMullin, J; Martin, R D; Massarczyk, R; Meijer, S J; Mertens, S; Orrell, J L; O'Shaughnessy, C; Poon, A W P; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Shanks, B; Shirchenko, M; Suriano, A M; Tedeschi, D; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Xu, W; Yakushev, E; Yu, C -H; Yumatov, V; Zhitnikov,
Search for the in-situ production of
No full textThe beta decay of Ge and Ge, both produced by neutron capture on Ge, is a potential background for Germanium based neutrinoless double-beta decay search experiments such as GERDA or the LEGEND experiment. In this work we present a search for Ge decays in the full GERDA Phase II data set. A delayed coincidence method was employed to identify the decay of Ge via the isomeric state of As (, , {T_{1/2} = {114}\,{\upmu }\hbox {s}}, As). New digital signal processing methods were employed to select and analyze pile-up signals. No signal was observed, and an upper limit on the production rate of Ge was set at nuc/(kg yr) (90% CL). This corresponds to a total production rate of Ge and Ge of nuc/(kg yr) (90% CL), assuming equal production rates. A previous Monte Carlo study predicted a value for in-situ Ge and Ge production of (0.21 ± 0.07) nuc/(kg.yr), a prediction that is now further corroborated by our experimental limit. Moreover, tagging the isomeric state of As can be utilised to further suppress the Ge background. Considering the similar experimental configurations of LEGEND-1000 and GERDA, the cosmogenic background in LEGEND-1000 at LNGS is estimated to remain at a sub-dominant level
GEMMA EXPERIMENT: THREE YEARS OF THE SEARCH FOR THE NEUTRINO MAGNETIC MOMENT
No full textThe result of the 3-year neutrino magnetic moment measurement at the Kalinin Nuclear Power Plant (KNPP) with the GEMMA spectrometer is presented. AntineutrinoÄelectron scattering is investigated. A high-purity germanium detector of 1.5 kg placed at a distance of 13.9 m from the 3 GW th reactor core is exposed to the antineutrino ux of 2.7 · 10 13 cm −2 · s −1 . The scattered electron spectra taken in (5184 + 6798) and (1853 + 1021) h for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment μν < 3.2 · 10 −11 μB at 90% CL is derived from the data processing. ‚ · ¡μÉ¥ ¶·¥¤¸É ¢²¥´·¥ §Ê²ÓÉ É É·¥Ì²¥É´¨Ì¨ §³¥·¥´¨°³ £´¨É´μ£μ ³μ³¥´É ´¥°É·¨´μ (OEOE) ¶μ³μÐÓÕ¸ ¶¥±É·μ³¥É· GEMMA´ Š ²¨´¨´¸±μ°'.ˆ¸¸²¥¤Ê¥É¸Ö · ¸¸¥Ö´¨¥ ·¥ ±Éμ·´ÒÌ ´-ɨ´¥°É·¨´μ ( ¶μÉμ± 2,7 · 10 13¸³−2 ·¸− 1 )´ Ô²¥±É·μ´ Ì 1,5-±£ £¥·³ ´¨¥¢μ£μ ¤¥É¥±Éμ· , ¶μ³¥Ð¥´-μ£μ´ · ¸¸ÉμÖ´¨¨13,9 ³ μÉ Í¥´É· ±É¨¢´μ° §μ´Ò¸É ´¤ ·É´μ£μ ·¥ ±Éμ· É¥ ¶²μ¢μ°³μдμ¸ÉÓÕ 3 ƒ‚É. μ ·¥ §Ê²ÓÉ É ³¸· ¢´¥´¨Ö¸ ¶¥±É·μ¢ Ô²¥±É·μ´μ¢ μɤ Ψ,¨ §³¥·¥´´ÒÌ § (5184 + 6798)( 1853 + 1021) Î ¶·¨· ¡μÉ ÕÐ¥³¨ § £²ÊÏ¥´´μ³ ·¥ ±Éμ·¥¸μμÉ¢¥É¸É¢¥´´μ,´ 90 %-³ Ê·μ¢´¥ ¤μ-Éμ¢¥·´μ¸É¨ ¶μ²ÊÎ¥´¢¥·Ì´¨° ¶·¥¤¥² OEOE: μν < 3,2 · 10 −11 μB
Performance of bare high-purity germanium detectors in liquid argon for the GERDA experiment
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Contamination control and assay results for the Majorana Demonstrator ultra clean components
No full textThe Results of Search for the Neutrino Magnetic Moment in GEMMA Experiment
No full textThe result of the neutrino magnetic moment measurement at the Kalinin Nuclear Power Plant (KNPP) with GEMMA spectrometer is presented. The antineutrino-electron scattering is investigated. A high-purity germanium detector with a mass of 1.5 kg placed at a distance of 13.9 m from the 3 GWth reactor core is exposed to the antineutrino flux of 2.7×1013 1/cm2/s. The recoil electron spectra taken in 18134 and 4487 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment μν< 2.9×10−11μB at 90% C.L. is derived from the data processing
Low background materials and fabrication techniques for cables and connectors in the Majorana Demonstrator
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