Sterile Neutrinos in Cold Climates [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 621.48 Nuclear engineering
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of High Energy Physics ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2015
• Mô tả vật lý: Size: 339 p. : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 268201
• Chủ đề: 1. 46 instrumentation related to nuclear science and technology; 2. 72 physics of elementary particles and fields; 3. Argon; 4. Neutrinos; 5. Time projection chambers

Tóm tắt

 Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system
  test-stand measurements of liquid argon optical properties with dissolved impurities
  optimization of wavelength-shifting coatings for liquid argon scintillation light detection
  testing and deployment of high-voltage surge arrestors to protect TPC field cages
  and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin<
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 , and the LSND and MiniBooNE allowed regions are excluded at >
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