Browsing by Subject "LAGUNA"
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(2013)Neutrino oscillation is a particle physics phenomenon, where neutrino flavour is not conserved. The phenomenon was conjectured during the 1950s by Pontecorvo and confirmed during the 1990s by Super-Kamiokande collaboration. Consequently, neutrinos must have Dirac or Majorana mass and a relevant mass term must be included in standard model. Neutrino oscillation is the first confirmed beyond standard model phenomenon. It leads to nonconservation of quantum numbers L_e, L_μ and L_τ. Currently the scientific community has detected three different neutrinos, but has failed in designating the mass hierarchy and absolute mass of them. In addition, charge-parity symmetry violation (CP violation) is expected, but yet unconfirmed in the neutrino oscillation. This thesis includes a brief historical journey to neutrino physics and a lengthy discussion of electroweak sector of standard model (Glashow–Weinberg–Salam theory), with detailed phenomenology of neutrino oscillations. GLoBES simulation program and its partner AEDL language is introduced. Experiment definition methods in AEDL are covered extensively. The most important parameters are neutrino flux, source power, target mass and baseline length. Statistical methods are represented briefly. Main tool is χ2-test. Neutrino sources are assumed to be 700 kW SPS at CERN, Switzerland, 450 kW particle accelerator Protvino, Russia and 5 MW particle accelerator at Lund, Sweden. The target is LAGUNA detector at Pyhäsalmi mine, Finland. Using specifications of LAGUNA detector currently on drawing board and SPS as the neutrino source, the confidence limits for determining neutrino mass hierarchy and discovering nonzero CP violation are calculated. Mass hierarchy is almost conclusively determined, most of the δ_CP parameter space exceed the 5σ limit, which is considered the limit for a confirmed scientific discovery. CP violation discovery is confirmed within 5σ limit with 70 % of δ_CP parameter space. Including both the SPS and Protvino accelerator neutrino fluxes, the covered parameter space is increased significantly with both mass hierarchy determination and CP violation discovery. Including also Lund accelerator neutrino flux, mass hierarchy is conclusively determined. CP violation discovery is confirmed within 5σ limit with 65 % of δ_CP parameter space and within 90 % limit with 85 % of δ_CP parameter space. Pyhäsalmi mine is 2288 km from CERN neutrino source. The baseline is very close to bimagic baseline 2540 km, which allows extremely good statistics and sensitivity of oscillation parameters. In conclusion, Pyhäsalmi mine should be given priority, when candidate sites are considered.
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