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Precise measurement of the electron antineutrino oscillation
Pěč, Viktor ; Vorobel, Vít (advisor) ; Trávníček, Petr (referee) ; Vénos, Drahoslav (referee)
The Daya Bay experiment is designed to precisely measure short-baseline disappearance of reactor antineutrinos from reactor cores at the Daya Bay nuclear power plant complex in the Guangdong Province of China. It pre- sented the most precise measurements of oscillation parameters sin2 2θ13 = 0.084 ± 0.005 and |∆m2 ee| = (2.42 ± 0.11) × 10−3 eV2 . Background to the antineutrino signals is mainly created by cosmic muons and is effectively suppressed by use of water Cherenkov and RPC muon detectors. This thesis describe testing of RPC detectors prior to their installation at the experi- mental site. Part of the cosmic muons stop in the experiment's antineutrino detectors, and they decay or are captured by 12 C producing 12 B. Isotope 12 B contribute to accidental background. Rates of muon decays in the detectors are estimated in the thesis. The experiment can register electron antineutri- nos from supernova with expected signals around 20 MeV. Energy scale of the detectors at 53 MeV is determined.
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Detailed Investigation of Electron Antineutrino Oscillations in the Daya Bay Experiment
Roskovec, Bedřich ; Leitner, Rupert (advisor) ; Šimkovic, Fedor (referee) ; Zálešák, Jaroslav (referee)
Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which...
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Detailed Investigation of Electron Antineutrino Oscillations in the Daya Bay Experiment
Roskovec, Bedřich ; Leitner, Rupert (advisor)
Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which...
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Measurement of scintillator light yield nonlinearity in the neutrino experiment JUNO
Tměj, Tomáš ; Vorobel, Vít (advisor) ; Krtička, Milan (referee)
In order to be able to determine neutrino mass hierarchy in the neutrino oscillation experiment JUNO we need to understand the dependence of the response of the signal from the scintillator on the deposited energy inside the scintillator. We measure the nonlinearity of the signal response via the Compton scattering inside the scintillator and via the precision gamma spectroscopy inside the HPGe detector. We observe effects of different parameters on the experiment via the Monte Carlo simulations. We also improve the data processing of the measured data and discuss what improvements of the experiment we can use in the future.
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Precise measurement of the electron antineutrino oscillation
Pěč, Viktor ; Vorobel, Vít (advisor) ; Trávníček, Petr (referee) ; Vénos, Drahoslav (referee)
The Daya Bay experiment is designed to precisely measure short-baseline disappearance of reactor antineutrinos from reactor cores at the Daya Bay nuclear power plant complex in the Guangdong Province of China. It pre- sented the most precise measurements of oscillation parameters sin2 2θ13 = 0.084 ± 0.005 and |∆m2 ee| = (2.42 ± 0.11) × 10−3 eV2 . Background to the antineutrino signals is mainly created by cosmic muons and is effectively suppressed by use of water Cherenkov and RPC muon detectors. This thesis describe testing of RPC detectors prior to their installation at the experi- mental site. Part of the cosmic muons stop in the experiment's antineutrino detectors, and they decay or are captured by 12 C producing 12 B. Isotope 12 B contribute to accidental background. Rates of muon decays in the detectors are estimated in the thesis. The experiment can register electron antineutri- nos from supernova with expected signals around 20 MeV. Energy scale of the detectors at 53 MeV is determined.
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Detailed Investigation of Electron Antineutrino Oscillations in the Daya Bay Experiment
Roskovec, Bedřich ; Leitner, Rupert (advisor) ; Šimkovic, Fedor (referee) ; Zálešák, Jaroslav (referee)
Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which...
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Methods of determination of neutrino mass hierarchy
Dohnal, Tadeáš ; Leitner, Rupert (advisor) ; Soustružník, Karel (referee)
In this thesis, the question of neutrino mass hierarchy is investigated. For this purpose, possibilities of neutrino mass origin are mentioned and phenomenology of neutrino oscillations within three active neutrino framework is introduced. Using that, it is described what neutrino mass hierarchy is and why it would be good to know it. After that, an overview of approaches to this problem is provided, including outline of the JUNO experiment. The approach based on comparison of mass splitting measured in experiments with reactor antineutrinos and accelerator neutrinos is investigated in great detail. The final part of this thesis is measurement of resistive plate chamber properties, as this type of detector was considered to be used in the JUNO experiment (but eventually other type will be used instead).
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Možnosti zkoumání oscilací elektronových (anti) neutrin z rozpadů mionů.
Dohnal, Tadeáš ; Leitner, Rupert (advisor) ; Pěč, Viktor (referee)
In this thesis, the phenomenon of neutrino oscillations is investigated. General phenomenology for the three active neutrino framework is provided, along with transition probabilities in vacuum. The effect of eventual CP violation on neutrino oscillations and difficulties of its measurement are introduced. Several solutions are discussed, especially the concept of the neutrino factory (i.e. using neutrinos from muon decays) as it is projected by the nuSTORM collaboration. Energy spectra of neutrinos from unpolarized muon decays, both at rest and in flight are calculated, along with the angular distribution and other specifications.
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Fyzika oscilací neutrin na experimentu NOvA
Nosek, Tomáš ; Soustružník, Karel (advisor) ; Roskovec, Bedřich (referee)
This thesis goes into the physics of neutrino oscillations and into possibility of measuring some of its parameters in the NOνA experiment: the mass hierarchy determination, whether there is a CP violation in neutrino oscillations, or the value of mixing angles θ13 and θ23 in particular. The standard formalism of 3 neutrinos model is summarized and the effect of matter to neutrino propagation through space is clarified. It is explained how to get information on yet unknown oscillation parameters. Using analytical approximations expected probabilities of muon to electron neutrino oscillation in NOνA configuration are calculated for different combinations of the mass hierarchy, CP violation, or angles that could be realized in nature. Main features of the NOνA experiment, its sensitivity and basic character of the results that can be obtained are described.
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Detailed Investigation of Electron Antineutrino Oscillations in the Daya Bay Experiment
Roskovec, Bedřich ; Leitner, Rupert (advisor)
Observed disappearance of reactor antineutrinos in the short baseline in Daya Bay can be explained by the phenomenon of neutrino flavour oscillations. The analysis in standard three- neutrino framework provides the best measurement of mixing angle of θ13 and the value of effective mass squared difference ∆m2 ee with comparable precision with other experiments. The unprecedented precision of Daya Bay motivates us to extend our search beyond standard three-neutrino oscillation scheme. It this thesis, we have explored two scenarios of possible physics Beyond Standard Model (BSM). We have tested the fundamental symmetry of the nature by searching for the Lorentz Invariance violation effect within the framework of the Standard-Model Extension (SME). Such an effect could be observed as a deviation from three- neutrino oscillation prediction in the oscillated antineutrino spectrum. Since we have not observed any significant deviation, we have been able to set the limits on the SME parameters. Some of the limits were measured for the first time while some turned out not to be competitive with the measurement of other experiments. We have also performed search for Non-standard Interactions (NSIs) in the Daya Bay. Being forbidden in the Standard Model, these interactions are predicted by BSM theories for which...
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