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Sibille, Valérian. "Mesure de l'angle de mélange θ₁₃ avec les deux détecteurs de Double Chooz." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS582/document.
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L'expérience Double Chooz a pour but de mesurer l'angle de mélange leptonique θ₁₃ avec précision. Pour ce faire, l'expérience met à profit deux détecteurs identiques -- remplis de liquide scintillant dopé au gadolinium -- afin d'étudier les $antinue$ produits par les deux réacteurs nucléaires de 4.25GWth de la centrale de Chooz. Le détecteur lointain -- situé à une distance moyenne de $SI{1050}{m}$ des coeurs -- prend des données depuis Avril 2011. Le détecteur proche -- à une distance moyenne de 400m des coeurs -- observe les réacteurs depuis Décembre 2014. Le paramètre de mélange θ₁₃ conduit à la disparition d'$antinue$, lorsque ceux-ci voyagent des coeurs jusqu'aux sites de détection; la dépendance en énergie de ce déficit permet d'extraire la valeur de sin² 2θ₁₃, par ajustement. Les systématiques de détection, ainsi que l'incertitude sur la prédiction du flux $antinue$, sont formidablement réduites par le biais de corrélations entre les détecteurs et la configuration iso-flux du site. Par conséquent, la précision relative à la mesure de θ₁₃ est dominée par les incertitudes sur les bruits de fond et sur la normalisation relative des taux d'$antinue$. Le bruit de fond principal provient de la désintégration des émetteurs βn -- produits par spallation des muons -- dans le détecteur lui-même. Les spectres de ces isotopes cosmogéniques ont été simulés et complétés par un traitement d'erreur rigoureux. Ces prédictions sont en bon accord avec les données, elles-mêmes extraites à l'aide d'un veto actif, dont la performance a été étudiée pour les deux sites. Le taux d'évènements cosmogéniques restant parmi les candidats $antinue$ a également été estimé. En outre, la normalisation relative du taux d'$antinue$, liée aux nombres de protons dans les cibles de chaque détecteur, a été évaluée. Tous ces travaux se sont inscrits au sein des premières analyses Double Chooz à l'aide de deux détecteurs, produisant sin² (2θ₁₃) = 0.111±0.018The Double Chooz experiment aims at accurately measuring the value of the leptonic mixing angle θ₁₃. To this intent, the experiment makes the most of two identical detectors -- filled with gadolinium-loaded liquid scintillator -- observing $antinue$'s released by the two 4.25GWth nuclear reactors of the French Chooz power plant. The so-called "far detector" -- located at an average distance of 1050m from the two nuclear cores -- has been taking data since April 2011. The "near detector" -- at an average distance of 400}m from the cores -- has monitored the reactor since December 2014. The θ₁₃ mixing parameter leads to an energy dependent disappearance of $antinue$'s as they propagate from the nuclear cores to the detection sites, which allows for a fit of the sin² 2θ₁₃ value. By reason of correlations between the detectors and an iso-flux site layout, the detection systematics and the $antinue$ flux uncertainty on the θ₁₃ measurement are dramatically suppressed. In consequence, the precision of the θ₁₃ measurement is dominated by the uncertainty on the backgrounds and the relative normalisation of the $antinue$-rates. The main background originates from the decay of βn-emitters -- generated by $mu$-spallation -- within the detector itself. The energy spectra of these cosmogenic isotopes have been simulated and complemented by a diligent error treatment. These predictions have been successfully compared to the corresponding data spectra, extracted by means of an active veto, whose performance has been studied at both sites. The rate of cosmogenic background remaining within the $antinue$ candidates has also been assessed. Addtionally, the normalisation of the $antinue$ rates, bound to the number of target protons within each detector, has been evaluated. All these works were part of the first Double Chooz multi-detector results, yielding sin² (2θ₁₃) = 0.111±0.018
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Manzanillas, Luis. "Development of the source calibration system of the STEREO experiment and search for sterile neutrinos at the ILL." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAY079/document.
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L'expérience STEREO a été proposé afin de donner une réponse sans ambiguïté àl'idée d'un état de neutrino stérile léger ($Delta m^{2}sim 1eV^{2}$) comme l'origine del'anomalie réacteur des antineutrinos. Le but de l'expérience est de confirmer ou de rejetercette hypothèse en recherchant un patron d'oscillation à courte distance (9-11 m) dans lespectre en énergie des $overline{nu_{e}}$'s émis par le réacteur nucléaire de recherchede l'Institut Laue-Langevin à Grenoble (France). A cet effet, le détecteur estcomposé de 2 tonnes du liquide scintillant dopé au Gd et lu par un réseau detubes photomultiplicateurs, et est segmenté en 6 cellules dans la direction depropagation des antineutrinos. Les $overline{nu_{e}}$'s sont détectés par le processusIBD en observant un signal corrélé dans letemps d'un dépôt d'énergie rapide d'un positron et un signal retardé produitpar la capture d'un neutron. La mesure des petites oscillations deformantle spectre d'énergie des antineutrinos nécessite une bonne résolution en énergieet une excellente connaissance de la réponse du détecteur. Ce manuscrit présenteune étude de simulation détaillée basée sur le logiciel Geant4 STEREO, ce quia permis le développement du système de calibration par sources. Ce système aété conçu pour répondre à toutes les exigences physiques de STEREO: calibrerl'échelle de l'énergie et de l'efficacité de capture de neutrons au niveau de 2%,connaître la réponse en énergie dans le spectre d'énergie réacteur antineutrino(1-8 MeV), étudier et la caractériser la réponse et des non-uniformités dudétecteur. A cet effet, on propose un système de calibration consistant en trois sous-systèmes:un sous-système automatisé pour déplacer des sources radioactives autour dudétecteur pour calibrer l'échelle en énergie dans chaque cellule de manièreindépendante. Un second sous-système pour déplacer une source AmBe sous ledétecteur, dont l'objectif est d'inter-calibrerl'efficacité de capture de neutrons entre les cellules. Enfin, un troisième systèmemanuel qui consistent en trois tubes de calibration placés à l'intérieur du liquidescintillante pour évaluer l'efficacité absolue de la capture des neutrons danstrois cellules différentes. La dernièrepartie de ce manuscrit est consacré à l'étude et la caractérisation du bruite de fond gammaet les signaux neutrino attendusThe STEREO experiment has been proposed to give an unambiguous responseto the hypothesis of a light sterile neutrino state ($Delta m^{2}sim 1 eV^{2}$)as the origin of the reactor antineutrino anomaly. Its goal is to confirm or reject thishypothesis by searching at short distance (9-11 m) for a neutrino oscillation patternin the energy spectrum of the $overline{nu_{e}}$’s emitted by the research nuclear reactorof the Laue-Langevin Institute in Grenoble (France). To this end, the detector iscomposed of 2 tons of Gd-loaded liquid scintillator read out by an array of PMTs, andis segmented in 6 cells in the direction of the $overline{nu_{e}}$’s propagation. Antineutrinosare detected via the IBD process by observing a time correlatedsignal composed of a prompt energy deposit from a positron and a delayed signal produced bythe neutron capture. Measuring small oscillations superimposed on the reactor antineutrinoenergy spectrum requires a good energy resolution and an excellent knowledge ofthe detector response. This manuscript presents a dedicated Geant4 simulation studyof a calibration system based on radioactive sources.This system has been conceived to fulfill all the STEREO physics requirements:calibrating the energy scale and the neutron capture efficiency at the 2 % level,knowing the energy response in the reactor antineutrino energy spectrum (0-8 MeV),and characterizing the detector response in a broader sense (non-uniformities, non-linearity,particle identification, etc). To this end, we proposethree calibration subsystems: one automated subsystem to moveradioactive sources around the detector, whose main role is to calibrate the energy scale in each cellindependently; a second subsystem to inter-calibrate the neutron captureefficiency between cells by moving an AmBe source under the detector; and finally,a third subsystem consisting in three manualcalibration tubes inside the liquid scintillator, necessary to assess the absolute neutron captureefficiency inside three different cells. The final part of this manuscript is devoted tothe study of the selection criteria, and the proposal of methods to reject the expected gammabackground
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Nakamura, Keigo. "Measurement of Neutrino Oscillation with a High Intensity Neutrino Beam." Kyoto University, 2019. http://hdl.handle.net/2433/236602.
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Iyer, Sharada Ramalingham. "A novel approach in the detection of muon neutrino to tau neutrino oscillation from extragalactic neutrinos." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/290068.
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A novel approach is proposed for studying the ν(μ) → ν(τ) oscillation and detection of extragalactic neutrinos. Active Galactic Nuclei (AGN), Gamma Ray Bursters (GRB) and Topological Defects are believed to be sources of ultrahigh energy ν(μ) and νₑ. These astrophysical sources provide a long baseline of 100Mpc, or more, for possible detection of ν(μ) → ν(τ) oscillation with mixing parameter Δm² down to 10⁻¹⁷ eV², many orders of magnitude below the current accelerator experiments. The propagation characteristics of upward going muon and tau neutrinos is studied to show that high energy tau neutrinos cascade down in energy as they propagate through the Earth, producing an enhancement of the incoming tau neutrino flux in the low energy region. By contrast, high energy muon neutrinos get attenuated as they traverse the Earth. It is observed that the relative steepness of the incoming neutrino flux spectrum and the nadir angle of the Earth are two important factors that influence the enhancement and cascade of nutau flux. This effect provides a novel way to search for tau neutrino appearance by measuring the angular dependence of tau neutrino induced upward muons; and upward hadronic and electromagnetic showers. A Monte Carlo evaluation of tau survival probability and its range shows that at energies below 10⁷ - 10⁸ GeV, depending on the material, only tau decays are important. However, at higher energies the tau energy losses are significant, hence reducing the survival probability of tau. Here, tau energy loss for energies up to 10⁹ GeV have been calculated taking into consideration the decay of tau. An understanding of tau energy loss at very high energies could help with the interpretation of long tracks produced by charged particles in large underground detectors.
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Salagnac, Thomas. "Recherche d'un neutrino stérile avec l'expérience STEREO : développement de l'électronique et identification des neutrinos." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY068/document.
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Depuis 2011, la réévaluation de plus d’une vingtaine de mesures de flux de neutrinos de réacteur mesurés à courtes distances suggère la présence d’un déficit de 7 % par rapport aux prédictions. Cette anomalie est statistiquement significative à environ 3 sigmas, tout comme une autre anomalie similaire correspondant à l’observation d’un déficit de neutrinos émis par des sources intenses de désintégrations beta. Ces anomalies peuvent être expliquées soit par un biais dans la prédiction des flux de neutrinos, soit par l’existence d’un nouvel état de neutrino, un neutrino stérile léger, vers lequel les trois neutrinos du modèle standard pourraient osciller. Ce nouveau neutrino, n’interagissant pas par interaction faible, serait uniquement « visible » grâce à ces oscillations. L’objectif de l’expérience STEREO est de répondre à la question de l’existence d'un neutrino stérile avec une masse de l’ordre de 1 eV, en utilisant le flux de neutrinos émis par le réacteur de recherche de l’« Institut Laue-Langevin » (ILL) à Grenoble, en France. Pour cela, le détecteur STEREO est segmenté en 6 cellules afin de mesurer l’hypothétique distorsion du spectre en énergie des neutrinos en fonction de la distance au réacteur (entre 9 et 11m de distance). Après quelques années de construction du détecteur et de préparation, l’expérience STEREO a pu commencer la prise de données en novembre 2016 avec une premier période d’acquisition qui s’est terminée en mars 2017. Cette thèse s’inscrit dans ces deux périodes distinctes de l’expérience STEREO. Une première partie a été consacrée à la caractérisation et la validation de l’électronique tout au long du processus de développement jusqu’à sa conception finale. Dans ce cadre, une méthode de mesure de la linéarité de la réponse en charge des photomultiplicateurs et de leurs embases a été développée avec une précision meilleure que 1 %, pour répondre au exigence de sensibilité à l’hypothèse d’un neutrino stérile. Cette exigence a d'ailleurs été validée par une analyse statistique de l’expérience. Une deuxième partie de la thèse a concerné l’analyse des premières données et plus particulièrement, l’identification des différents types de bruit de fond et la recherche des candidats neutrinosSince 2011, the re-evaluation of about twenty neutrino flux measurements at short distance from reactors suggests a deficit of about 7 % with respect to predictions. This anomaly has a 3 sigmas significance, as another similar anomaly which corresponds to the deficit of neutrinos emitted from intense source of beta-decay. These anomalies could be explain either by a bias in the flux prediction or by the existence of a new neutrino state, a light sterile neutrino, possibly mixing with the three neutrino states of the standard model. This new neutrino, with no ordinary weak interaction, could only be “visible” via the neutrino oscillation. The STEREO experiment goal is to answer the question of the sterile neutrino existence with mass around 1 eV, using neutrino flux emitted from the research reactor of the « Institut Laue-Langevin » (ILL) at Grenoble, France. To achieve this, the STEREO detector is segmented in 6 cells to measure a hypothetical distortion of the neutrino energy spectrum at different distances from the reactor (between 9 et 11m). Afters few years of detector construction and preparation, the STEREO experiment has started taking data in November 2016 with a first period over in Mars 2017. This thesis took place during two distinct phases of the STEREO experiment. A first part was dedicated to the characterisation and the validation of the electronics, during all its development process until its final conception. In this context, a method to measure the charge response linearity of photomultipliers and their bases, with a precision better than 1 %, has been developed, in order to fulfill the desired sensitivity to the light sterile neutrino hypothesis. This requirement on the precision has been validated by a statistical analysis of the experiment. The second part of the thesis was devoted to the analysis of the first data and more particularly to the identification of the different kinds of background and to the search of neutrino candidates
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Shiraishi, Kiyoshi Keola. "Super-kamiokande atmospheric neutrino analysis of matter-dependent neutrino oscillation models /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/9771.
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Wang, Tse-Chun. "New physics at the neutrino oscillation frontier." Thesis, Durham University, 2018. http://etheses.dur.ac.uk/12549/.
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The discovery of neutrino oscillations implies that neutrinos are massive, and therefore is a concrete evidence that the standard model (SM), which forbids the mass of neutrinos, is not complete. As a consequence, completing the knowledge of neutrino oscillations extends our understanding of new physics. We are entering the age of precision measurement of neutrino oscillations, with the preparation for the upcoming Long Baseline experiments (LBL) — Deep Underground Neutrino Experiment (DUNE) and Tokai to Hyper-Kamiokande (T2HK). In this thesis, we firstly study how DUNE, T2HK and the combination solve the remaining problems of the standard neutrino oscillation — octant and mass ordering degeneracy problems, if CP violates, and what the value of CP phase δ is. In the following, we study how Littlest Seesaw Models (LS) can be tested by DUNE, T2HK together with short- and medium-baseline reactor experiments, after fitting these models with the current global results. In the next half of this thesis, we extend our discussion to allow external interactions — nonstandard interactions (NSIs) in matter for DUNE. After reviewing current studies on the precision of NSI-parameter measurement, we discuss the exclusion ability of DUNE to the SM prediction over the possible scenarios. Considering NSIs are flavour-dependent, we demonstrate the possible correlations between or among NSI effects under flavour symmetries A4 and Z2. Based on these correlations, we present how DUNE can test flavour symmetries A4 and Z2 through NSIs. Our results show the experimental properties of DUNE and T2HK, and how they perform for the theory of flavour symmetry.
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Wilkinson, Callum. "Constraining neutrino interaction uncertainties for oscillation experiments." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/9198/.
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Neutrinos rarely interact, but sometimes they do. How much? And does it matter? Charged-Current Quasi-Elastic (CCQE) neutrino-nucleus interactions are the main signal channel for T2K and other currently running neutrino oscillation experiments, but in recent years, with a number of experimental results, it has become clear that these interactions are not as well understood at few-GeV neutrino energies as was previously thought. This thesis focuses on the impact that this uncertainty will have on neutrino oscillation measurements. Published CCQE and the closely related Neutral-Current Elastic (NCEL) cross section results from the MiniBooNE experiment are used to fit a 3+1 sterile neutrino model, and the uncertainty over fundamental parameters in the cross section model used is shown to badly bias the results. Conservative sterile neutrino limits which treat the cross section uncertainty correctly are used, and a general note of caution is sounded over sterile neutrino results which make tacit and unfounded assumptions about the neutrino cross section model. New theoretical models of CCQE scattering which try to explain the experimental situation have become available, some of which have been implemented into NEUT, T2K's primary interaction generator. Two candidate models are used in a fit to all published CCQE data on nuclear targets to select a default model and constrain the parameters of that model in order to increase the sensitivity of T2K oscillation analyses. This CCQE parametrisation will be used for T2K oscillation analyses from the summer of 2015 onwards. The fit framework developed for this work has been integrated into the T2K oscillation analysis framework for future iterations. Additionally, the implementation of one such model, the Effective Spectral Function is described and compared with the available neutrino-nucleus scattering data.
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Kato, Issei. "Indications of neutrino oscillation in K2K experiment." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/145479.
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Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第11175号
理博第2843号
新制||理||1425(附属図書館)
22759
UT51-2004-T144
京都大学大学院理学研究科物理学・宇宙物理学専攻
(主査)教授 西川 公一郎, 教授 今井 憲一, 教授 谷森 達
学位規則第4条第1項該当
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Duffy, Kirsty. "Measurement of the neutrino oscillation parameters sin²θ23 Δm²32, sin²θ13, and σCP in neutrino and antineutrino oscillation at T2K." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:4485185d-3f72-49d0-866c-af2bab55d916.
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The T2K experiment is a long-baseline neutrino oscillation experiment, in which a muon neutrino beam is directed over a 295 km baseline from the J-PARC facility to the Super-Kamiokande detector. This allows neutrino oscillation to be studied in two channels: disappearance of νμ and appearance of νe. The T2K beam can be run either in neutrino or antineutrino configuration, for a neutrino beam which is predominantly composed of νμ or anti -νμ respectively. This thesis presents the first oscillation analysis to combine neutrino-mode and antineutrino-mode data sets, giving the first ever sensitivity to the CP-violating phase δCP from T2K data alone, as well as the most precise T2K measurement of the other neutrino oscillation parameters. The analysis uses a Markov Chain Monte Carlo method to construct a sample from the Bayesian posterior distribution, from which the oscillation parameters of interest and their uncertainties are estimated. Data samples from the T2K near detector, ND280, are fit simultaneously with data from the far detector in order to reduce the uncertainty in the far-detector prediction. When fitting the T2K data alone, the best-fit oscillation parameter values are sin2 θ23= 0.519+0.031-0.059, sin2 θ13= 0.0257+0.0106-0.0440, Δm232= 2.54+0.12-0.10 x 10-3eV2,and δCP=-1.91 rad. The 90% credible interval for δCP excludes values around π/2: δCP ∉ [0.38, 2.60] rad. When fitting the T2K data with a constraint on sin2 θ13 from measurements by reactor experiments, the best-fit oscillation parameter values are sin2 θ23= 0.519+0.061-0.029, sin2 θ13= +0.0014-0.0014, Dm232= 2.54+0.12-0.12 x 10-3eV2, and δCP=-1.72 rad. The 90% credible interval for δCP contains values δCP ∈ [-3.10,-0.17] rad, excluding the CP-conserving values 0 and ± π at 90% probability.
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Smith, Miles Walter Eldon. "An investigation of matter enhanced neutrino oscillation with the Sudbury Neutrino Observatory /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/9701.
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Huber, Patrick. "Three flavour effects in future neutrino oscillation experiments." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969864272.
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Otani, Masashi. "Measurement of Neutrino Oscillation in the T2K Experiment." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/157756.
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Blanchet, Adrien. "Recherche du neutrino stérile auprès du réacteur de l’ILL : expérience Stereo." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS269/document.
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La thèse de doctorat porte sur la physique des neutrinos de réacteurs. L'étude de plus en plus précise des spectres d'antineutrinos des réacteurs a mis à jour une déviation entre la prédiction et les mesures qui pourrait indiquer l'existence d'un nouveau neutrino, non couplé avec l'interaction faible (un neutrino stérile) et de masse autour de 1 ₑV/c². L'expérience STEREO vise à tester l'hypothèse du neutrino stérile auprès du réacteur ILL de Grenoble. Le principe de STEREO repose sur 6 cellules de détection identiques disposées entre 9 et 11.5 m de distance du cœur du réacteur de recherche de l'ILL. Le détecteur a commencé la prise de données en novembre 2016, et les premiers résultats ont été publiés dès 2018. Le travail effectué pendant la thèse a consisté dans un premier temps à caractériser la réponse en énergie du détecteur. Pendant la première phase de prise de données, des défaillances matérielles se sont manifestées entrainant le découplage optique d'une cellule et une augmentation progressive des fuites de lumière entre cellules. Ces deux aspects ont contraint l'analyse de données à développer un algorithme de reconstruction des dépôts d'énergie qui corrige les fuites lumières au premier ordre. Un important travail sur la mesure des paramètres de cette méthode a été entrepris afin d'assurer que l'échelle en énergie soit bien reproduite dans la simulation GEANT4. L'estimation des incertitudes systématiques sur l'échelle en énergie a été effectuée en se servant des bruits de fond cosmogéniques. Le second aspect majeur abordé pendant la thèse est l'analyse statistique et la génération des contours d'exclusion de l'hypothèse du neutrino stérile. La déduction statistique a été conduite en s'inspirant de la méthode de Feldman et Cousins (1999) sur la génération d'intervalles de confiance fréquentistes. Un formalise en X² a spécialement été développé pour mener une analyse d'oscillations indépendante des prédictions de flux et de forme des spectres antineutrinos. Les erreurs statistiques et systématiques ont été propagées à l'aide de matrices de covariance et les lois de X² ont été calculées en générant des pseudo-expériences. L'ensemble des travaux menés pendant cette thèse de doctorat a contribué à la publication de trois papiers présentant les résultats de l'expérience STEREOThe doctoral thesis focuses on the physics of reactor neutrinos. The increasingly precise study of antineutrinos spectra from reactors has revealed a deviation between the prediction and the measurements, which could indicate the existence of a new neutrino. This new neutrino state would not couple with the weak interaction (a sterile neutrino) and its mass would be around 1 ₑV/c². The STEREO experiment aims at testing the sterile neutrino hypothesis at the ILL reactor in Grenoble-France. The principle of the STEREO experiment is based on 6 identical detector cells aligned between 9 and 11.5 m distance from the core of the ILL research reactor. The detector started taking data in November 2016, and the first results were published in 2018. The work carried out during the thesis initially consisted in characterizing the detector's energy response. During the first phase of data taking, hardware failures occurred leading to the optical decoupling of a cell and a gradual increase in light cross-talk between cells. These two aspects have compelled data analysis to develop a dedicated energy deposit reconstruction algorithm that corrects first-order light leaks using a matrix formalism. Significant work on the measurement of the parameters of this method was undertaken to ensure that the energy scale was well reproduced in the GEANT4 simulation. The estimation of systematic uncertainties on the energy scale was performed using cosmogenic background events. The second major aspect addressed during the thesis is the statistical analysis and generation of exclusion contours of the sterile neutrino hypothesis. The statistical inference was built using the Feldman and Cousins (1999) method by generating frequentist confidence intervals. A formalization in X² has been specially developed to conduct the oscillation analysis independently of any flux or shape prediction of the antineutrino spectra. Statistical and systematic errors were propagated using covariance matrices and X² laws were constructed by generating pseudo-experiments. All the work carried out during this doctoral thesis contributed to the publication of three papers presenting the results of the STEREO experiment
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Pequignot, Maxime. "Les expériences Nucifer et Stéréo : étude des antineutrinos de réacteurs à courte distance." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112194/document.
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Interagissant très peu avec leur environnement, les neutrinos peuvent aujourd'hui être clairement détectés à l'aide d'une technologie largement éprouvée reposant sur l'utilisation de liquide scintillant et de photo-multiplicateurs. Les progrès réalisés ces dernières années permettent de réduire la taille et la complexité des détecteurs et laissent ainsi entrevoir les premières applications à ces particules. Première expérience placée à 7,2 m d'un coeur de réacteur nucléaire, le détecteur Nucifer démontre la possibilité de compter les antineutrinos venant du combustible à cette faible distance induisant un environnement très défavorable en terme de bruits de fond. Dans cette thèse, nous présentons l'analyse ayant permis de rejeter les différents bruits de fond venant du réacteur et de son circuit de désactivation mais aussi des muons atmosphériques. Une prédiction du taux d'antineutrinos avec différentes simulations Monte-Carlo a également été réalisée et se trouve en accord avec le taux mesuré dans la limite des incertitudes statistiques et systématiques. Sur près d'un an de prise de données, nous avons pu suivre l'évolution en puissance du réacteur Osiris. Une étude de sensibilité a montré que la présence de plutonium dans le coeur d'Osiris était détectable à 95 % CL dès que cet isotope contribue à hauteur de 10 % de la masse fissile (1,5 kg dans Osiris). En outre, le détecteur a montré une grande stabilité tout au long de la prise de données prouvant que le contrôle à distance des réacteurs nucléaires est possible. Cette expérience ouvre donc la voie à de nouveaux modes de contrôle des réacteurs nucléaires pour les autorités de sûreté. Dans le cadre des travaux sur les spectres d'antineutrinos émis par les réacteurs nucléaires, un déficit a récemment été mis en évidence dans le taux des antineutrinos mesurés pour les expériences à courte distance des réacteurs. Ce déficit, appelé anomalie réacteur, pourrait trouver son origine dans une nouvelle oscillation à travers un état stérile du neutrino à l'électronvolt. L'expérience Stéréo a pour but de trancher sur l'existence ou non de cette oscillation en se plaçant à 10 m du réacteur nucléaire de l'ILL. En observant une distorsion à la fois en énergie et en distance, le détecteur permettra en effet d'apporter une conclusion solide sur ce phénomène. Nous revenons ici sur le développement du projet et sur les différents choix technologiques réalisés pour améliorer la sensibilité de l'expérience. Une attention particulière est portée sur l'estimation des bruits de fond provenant du réacteur nucléaire ainsi que des expériences voisines utilisant des faisceaux de neutrons. Des mesures expérimentales alliées à des simulations ont permis de quantifier les flux de rayons gammas et de neutrons ainsi que leur direction afin de prévoir les blindages nécessaires. Enfin, nous présentons les performances du prototype correspondant à une cellule du détecteur finalIn spite of a faint interaction with their environment, neutrinos can be now clearly detected thanks to a proven technology based on liquid scintillators and photomultiplier tubes. The advances made these last years allow to reduce the size and the complexity of the detectors and therefore naturally lead to the first applications with these particles. As the first experiment to be placed at 7.2 m of a nuclear core, the Nucifer detector demonstrates the possibility of counting antineutrinos coming from the nuclear fuel at such a short baseline despite the very unfavourable environment in term of the background noises. In this thesis, we present an analysis which rejects the various background noises coming from the reactor and its deactivation circuit but also from the atmospheric muons. A prediction of the antineutrino rate with several Monte-Carlo simulations was also performed and is in good agreement with the measured rate, within statistical and systematic uncertainties. After nearly one year of data taking, we were able to follow the power evolution of the reactor Osiris. A sensibility study showed that the presence of plutonium in the Osiris core was detectable at 95 % CL as soon as this isotope contributes at the level of 10 % of the fissile mass (1,5 kg in Osiris). Besides, the detector was very stable throughout the data taking proving that the remote control of nuclear reactor with a neutrino detector is possible. Thus, this experiment opens the way to new control modes of nuclear reactors by the nuclear safety authorities. As part of the work on the antineutrino spectra emitted by nuclear reactors, a deficit was recently highlighted in the observed antineutrino rate for the experiments at short baseline. This deficit, called the reactor anomaly, could be explain by a new oscillation into a sterile state of the neutrino at the electronvolt scale. The Stereo experiment aims to test the existence of this oscillation by performing measurements 10 m away from the ILL nuclear reactor. By observing a distortion pattern of the energy and distance dependence of the neutrino spectrum, the detector will be able to provide a solid proof of this phenomenon. We present here the project development and the various technological choices that we have done to improve the experiment sensibility. The estimation of the background noise coming from the nuclear reactor as well as the nearby experiments using neutron beams has been performed with on-site measurements and simulations to design the shielding of the detector. Eventually we present the performances of the prototype which corresponds to one cell of the final detector
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Waldron, Abigail V. "Neutrino oscillation parameters from νe appearance in the T2K experiment." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:7c6ba6ac-68ff-4564-986c-6dde4e9708cb.
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The T2K Experiment is a long-baseline accelerator neutrino oscillation experiment, whose primary aim is to look for νe appearance in a νμ beam. A predominantly νμ beam is produced at J-PARC in Tokai on the east coast of Japan, and neutrino interactions are measured both by a near detector complex, 280 m from the neutrino production target,and by a large water Cerenkov detector, Super-Kamiokande, 295 km away. This thesis is concerned with oscillations νμ → νe, within both a standard three neutrino model and a model in which there is one additional sterile neutrino. By looking at νe appearance over the T2K baseline, this thesis looks for oscil- lations involving one additional sterile neutrino. A region of the short baseline neutrino oscillation parameter space favoured by other experiments is excluded at 3σ. The ND280 is also used to search for νe appearance over a short baseline. A νe selection is developed, and limits on the short baseline oscillation parameter space are set. Sensitivity predictions are also made for future T2K running. The T2K ND280 is interesting for this work since the detector technology is different to that of other experiments that have seen indications of short baseline electron-neutrino appearance. In the standard three-flavour neutrino oscillation picture, a combined analy- sis of the electron-neutrino appearance results of T2K and another long-baseline accelerator neutrino experiment, MINOS, is presented. Combining the two re- sults with the Feldman-Cousins method results in sin2 2θ13 = 0 being excluded at 2.7σ, assuming the normal neutrino mass hierarchy.
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Kempe, Daniel. "Investigation of the Effects of Invisible Neutrino Decay at the Proposed ESSnuSB Experiment." Thesis, KTH, Fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298359.
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This thesis studies neutrino oscillations at the proposed ESSnuSB experiment and the effects of invisible decay, where the neutrino mass states are assumed to be able to decay, on the planned measurements and the physics potential for this experiment to detect neutrino decays. This is accomplished by simulating a combined scenario of neutrino oscillations and invisible neutrino decay. It is found that the ESSnuSB experiment would be able to put a bound on the decay parameter $\tau_3 / m_3 = 2.64 (1.68) \times 10^{-11}$~s/eV for the baseline option $360 (540)$~km at $3\sigma$. Further, the effect of invisible neutrino decay on measurements of CP-violation and the precision measurements of $\delta_{\mathrm{CP}}$ for both baseline options are investigated. The results show that the effect is not significant in any case for CP-violation measurements. A significant difference in the precision measurements of $\delta_{\mathrm{CP}}$ is found only when decay is assumed to exist but is not accounted for in the theoretical model.Det här arbetet undersöker neutrinooscillationer vid det föreslagna experimentet ESSnuSB och ett nytt scenario med osynligt sönderfall av neutriner, där neutriner antas sönderfalla till partiklar som inte växelverkar. Arbetet undersöker hur väl ESSnuSB experimentet kan skilja en modell med neutrinosönderfall från Standardmodellen för neutriner utan sönderfall och hur experimentets andra tester påverkas av neutrinosönderfall. Studien har genomförts genom att simulera en kombinerad modell av neutrinooscillationer och neutrinosönderfall för ESSnuSB-experimentet. Analysen visar att ESSnuSB-experimentet skulle kunna sätta en $3\sigma$-gräns på sönderfallsparametern $\tau_3 / m_3 = 2.64 (1.68) \times 10^{-11}$~s/eV för baslinjelängden $360 (540)$~km. Vidare så studeras hur neutrinosönderfall påverkar mätningar av CP-symmetribrott och precisionsmätning av parametern $\delta_{\mathrm{CP}}$ för båda baslinjelängderna. Resultaten visar att påverkan av neutrinosönderfall på mätningar av CP-symmetribrott är liten. En signifikant skillnad i precisionsmätning av $\delta_{\mathrm{CP}}$ kan ses enbart då neutrinosönderfall antas sant men inte inkluderas i den teoretiska modellen.
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Fischer, Vincent. "Beta-decay emitted electronic antineutrinos as a tool for unsolved problems in neutrino oscillation physics." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066237/document.
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Le cadre global des oscillations de neutrinos est maintenant bien compris et nous quittons une ère d'exploration pour une ère de précision. L'expérience Double Chooz a pour but de mesurer l'angle de mélange theta13 par l'étude des oscillations des antineutrinos électroniques produits par les réacteurs de la centrale nucléaire de Chooz. Dans cette thèse, une sélection préliminaire des neutrinos détectés dans le détecteur proche est présentée. Les résultats les plus récents de Double Chooz, desquels sont extraits la mesure de theta13 la plus précise que l'expérience peut fournir à ce jour, seront également discutés. La géométrie de l'expérience, relativement simple, représente un avantage considérable afin d'effecteur des études de directionalité des neutrinos dont les résultats, obtenus en analysant les jeux de données les plus récents avec captures sur Gd et H, sont présentés. Ce concept de directionalité peut être appliqué à l'astronomie/astrophysique en offrant la possibilité de localiser des supernovas après détection de leurs neutrinos. Les résultats de simulations de directionalité effectuées avec différentes combinaisons de détecteurs seront présentées. Enfin, plusieurs anomalies pourraient s'expliquer par l'existence de nouveaux états, stériles, de neutrinos. Le but de l¿expérience CeSOX est de confirmer ou réfuter cette hypothèse en déployant une source radioactive à coté d'un grand détecteur comme KamLAND ou Borexino. Dans cette thèse seront présentés les résultats des simulations de signaux et de bruits de fond effectuées afin de valider le principe de l'expérience et de s'assurer de sa sensibilité à l'observation d'une oscillation vers un neutrino stérileThe framework of neutrino oscillations is quite well-understood and now requires precision rather than exploration. The Double Chooz experiment aims at measuring the theta13 mixing angle through the oscillations of electronic antineutrinos produced by the reactors of the Chooz nuclear power plant. The comparison of the interaction rates and spectral shapes in the two Double Chooz's detectors allows the observation of a disappearance and a spectral distortion, both driven by theta13. In this thesis, a preliminary neutrino selection with the near detector, whose data taking started in December 2014, has been performed. The most recent results of Double Chooz, providing the most precise measurement of the experiment, are presented as well.The simple layout of Double Chooz is a strong advantage to conduct directionality studies. Results of these studies using the most recent neutrino candidates with neutron captures on Gd and H are showed. Neutrino directionality can be applied to astronomy, with the localization of core-collapse supernovae. To this purpose, results of directionality measurements performed with combinations of large neutrino detectors over the globe are presented.Finally, recent anomalies observed in short baseline experiments provided hints of the hypothetical existence of additional sterile neutrino states. The goal of the CeLAND/CeSOX experiment is to test this hypothesis by deploying a radioactive source next to a large liquid scintillator detector such as KamLAND or Borexino. In this thesis, are presented results of signal and background simulations performed to validate the design and assess the sensitivity of such an experiment
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Ieki, Kei. "Observation of νμ→νe oscillation in the T2K experiment." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188474.
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Hasegawa, Masaya. "Measurement of neutrino oscillation parameters with neutrino-nucleus interaction studies in the K2K experiment." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144175.
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Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第12092号
理博第2986号
新制||理||1445(附属図書館)
23928
UT51-2006-J87
京都大学大学院理学研究科物理学・宇宙物理学専攻
(主査)助教授 中家 剛, 教授 今井 憲一, 教授 西川 公一郎
学位規則第4条第1項該当
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Hernández-Cabezudo, Álvaro [Verfasser], and T. [Akademischer Betreuer] Schwetz-Mangold. "Sterile Neutrino Searches in Neutrino Oscillation Experiments / Álvaro Hernández-Cabezudo ; Betreuer: T. Schwetz-Mangold." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/1212512391/34.
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Godley, Andrew. "A search for nu(mu) to nu(e) oscillations in the NOMAD experiment." University of Sydney. Physics, 2001. http://hdl.handle.net/2123/374.
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The NOMAD experiment is a neutrino oscillation experiment, capable of identifying \nm, \nmb, \nel, \neb\ and \nt\ for use in oscillation analyses. A search for \mutoe\ oscillations is conducted, emphasising the development of two separate beam simulators, to provide the background, (no oscillation), \nel\ signal. Both beam descriptions include fits to the results of the SPY experiment that measured hadron production from a 450~GeV proton beam on beryllium target. An independent analysis of the raw SPY data to produce the particle yield is reported. A series of criteria are described for the selection and classification of neutrino events. These produce the data samples necessary for both tuning the beam simulation and determining the oscillation signal. The development of a GEANT and FLUKA based Monte Carlo beam simulator is presented, providing good agreement to the measured neutrino beam. This simulation method has sizeable variations depending on the beamline geometry, which is not known precisely. This causes large systematic errors. An empirical parametrisation is proposed and used for the first time in a NOMAD oscillation search. It uses the measured neutrino spectra at NOMAD, except the \nel, to infer the meson production at the target, and then predict the \nel\ spectrum. This method has good agreement with the data and is also insensitive to alterations of the beamline geometry, resulting in much smaller systematic errors. The reduction of the systematic errors allows the \mutoe\ oscillations search to be performed with much greater precision. Comparisons of the \nel/\nm\ ratio between the empirical parametrisation and data yields no evidence for \mutoe\ oscillations, setting a limit on the mixing parameter, $sin^2(2 \theta) < 1.9 \times 10^{-3} \mbox{(90\% CL)}$ at high $\Delta m^2$. The present sensitivity of the analysis on the mixing parameter is 0.0017.
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Godley, Andrew. "A search for nu(mu) to nu(e) oscillations in the NOMAD experiment." Thesis, The University of Sydney, 2000. http://hdl.handle.net/2123/374.
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The NOMAD experiment is a neutrino oscillation experiment, capable of identifying \nm, \nmb, \nel, \neb\ and \nt\ for use in oscillation analyses. A search for \mutoe\ oscillations is conducted, emphasising the development of two separate beam simulators, to provide the background, (no oscillation), \nel\ signal. Both beam descriptions include fits to the results of the SPY experiment that measured hadron production from a 450~GeV proton beam on beryllium target. An independent analysis of the raw SPY data to produce the particle yield is reported. A series of criteria are described for the selection and classification of neutrino events. These produce the data samples necessary for both tuning the beam simulation and determining the oscillation signal. The development of a GEANT and FLUKA based Monte Carlo beam simulator is presented, providing good agreement to the measured neutrino beam. This simulation method has sizeable variations depending on the beamline geometry, which is not known precisely. This causes large systematic errors. An empirical parametrisation is proposed and used for the first time in a NOMAD oscillation search. It uses the measured neutrino spectra at NOMAD, except the \nel, to infer the meson production at the target, and then predict the \nel\ spectrum. This method has good agreement with the data and is also insensitive to alterations of the beamline geometry, resulting in much smaller systematic errors. The reduction of the systematic errors allows the \mutoe\ oscillations search to be performed with much greater precision. Comparisons of the \nel/\nm\ ratio between the empirical parametrisation and data yields no evidence for \mutoe\ oscillations, setting a limit on the mixing parameter, $sin^2(2 \theta) < 1.9 \times 10^{-3} \mbox{(90\% CL)}$ at high $\Delta m^2$. The present sensitivity of the analysis on the mixing parameter is 0.0017.
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Kandzia, Felix. "Recherche de neutrino stérile par l'expérience STEREO : optimisation du blindage et calibration de l'échelle d'énergie." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY086/document.
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La recherche de neutrinos stériles et légers est, à l’heure actuelle, l’un des enjeux majeurs de laphysique des neutrinos. Une indication de leur existence résulte de l’anomalie des antineutrinosde réacteur, qui découle du déficit de 6% entre les taux prédits et les taux observéspar les expériences à courte distance de réacteurs. Ce déficit peut être interprété comme uneoscillation à courte distance des neutrinos. L’objectif de l’expérience STEREO, situé auprès duréacteur de recherche de l’Institut Laue Langevin (ILL), à Grenoble, France, est d’étudier cetteoscillation. La cible du détecteur de neutrinos est placée entre 8,9 et 11,1m du coeur compactdu réacteur d’ILL. Le détecteur consiste d’environ 2t d’un scintillateur liquide, dopé avec duGd. Le volume actif est séparé dans le sens de la longueur en six cellules. Les antineutrinos sontdétectés par la désintégration bêta inverse, où ils interagissent avec un proton libre (ion H+) etproduisent un positron et un neutron. Les deux particules sont détectées dans le scintillateurpar une coïncidence retardée où le positron crée un signal prompt et le neutron est capturéaprès un temps de modération. La lumière produite par le scintillateur est mesurée par lesphotomultiplicateurs (PM). Le détecteur est complété par un“gamma catcher” qui entoure la cible et par un veto à muons.Ce manuscrit présente des études concernant la préparation et la mise en exploitation del’expérience STEREO. La conception du blindage magnétique des PM a été menée sur la basede simulations par éléments finis afin d’examiner différentes options, d’étudier en détail lesperformances de l’option retenue ainsi que de déterminer la qualité nécessaire des matériauxutilisés. Sur la base de ces études, la collaboration a retenu un plan de blindage en deuxcouches: une couche de fer doux à l’extérieur, couvrant le détecteur et le veto à muons, et unecouche de mu-métal autour de la cible. Ce blindage réduit les champs magnétiques externes à laposition des PM de la cible à moins de 60μT pour toutes les configurations connues de champsexternes. Ceci réduit à moins de 2% une variation de l’amplification des PM induite par deschangements des champs magnétiques.D’autre part, des études du bruit de fond sur le site de STEREO ont été menées. Unecartographie du bruit de fond du rayonnement gamma a été effectuée avec des détecteurs augermanium et un scintillateur NaI, afin de valider l’efficacité du blindage installé. Uneestimation du taux de bruit de fond est présentée et comparée au taux mesuré avec STEREO.Dans l’état actuel de l’analyse des données, le bruit de fond de coïncidences fortuites est inférieurau bruit de fond corrélé induit par les muons cosmiques. Après une première phase d’exploitationde STEREO, un “doigt de gant” en fin de vie situé à l’avant de STEREO a dû être retiré.Un bouchon était adapté à l’extrémité de ce doigt de gant afin de réduire le bruit du fondpour STEREO. Ce dispositif n’ayant pas pu être réinstallé à la suite l’enlèvement du doigt degant, un nouveau blindage a été proposé par l’ILL. Une série des simulations neutroniques etphotoniques (MCNP) a été effectué pour étudier l’effet de ce changement sur le bruit de fondautour de STEREO et pour décider si le blindage proposé était suffisant. Les deux scénariosavant et après l’enlèvement ont été comparés et selon cette simulation, la situation du bruit defond devrait être améliorée.Enfin une procédure a été proposée et appliquée pour analyser les données de calibration del’échelle d’énergie de STEREO. La procédure a été élaborée pour être applicable pour toutes lessources de calibration disponibles et pour minimiser les incertitudes systématiques. Le résultatpeut être utilisé pour ajuster les paramètres de la simulation Geant4 du détecteur développée parla collaboration, par comparaison avec des données mesurées et après pour déterminer l’échellede l’énergie avec la précision requise de < 2%Light sterile neutrinos are currently a topic actively discussed in neutrino physics. Oneindication of their possible existence and their participation in neutrino oscillations is the ReactorAntineutrino Anomaly, which states a deficit of about 6% between predicted and observedantineutrino fluxes in short baseline reactor neutrino experiments. The STEREO experimentaddresses this anomaly by searching for neutrino oscillations at baselines of 8.9-11.1m from thecompact core of the research reactor of the Institut Laue Langevin (ILL), Grenoble, France. Forthis purpose a Gd-loaded liquid scintillator detector was designed with an active target massof about 2 t. The target volume is subdivided in six optically separated cells along the line ofpropagation of the neutrinos. The electron antineutrinos emitted from the reactor are detectedvia the inverse beta decay on hydrogen nuclei, where a positron and a neutron are created. Thesetwo particles are detected in the scintillator in delayed coincidence, with the prompt signal fromthe positron and a delayed signal from neutron capture. The scintillation light created in theprocesses is read out by photomultiplier tubes (PMTs) on top of the detector cells. The detectoris completed by a gamma catcher and a muon veto.This manuscript covers parts of the preparation and the commissioning of the STEREOexperiment. As basis for the design process of the magnetic shielding for STEREO’s PMTsa series of finite element simulations was performed. The studies of different general layoutsand required material qualities as well as of details of the final design are summarised. Underconsideration of these studies the collaboration opted for a shielding design, a double layer setupwith an outer soft iron and inner mumetal layer, which has the required shielding efficiency toreduce the magnetic field at the position of the detector PMTs below 60 μT for all known externalmagnetic field configurations. This limits the maximum PMT gain change due to variations ofthe external magnetic fields to < 2%.Furthermore different studies have been performed concerning the on-site background situation.A mapping of the-ray background was conducted with high purity germanium detectorsand a NaI scintillator detector, in order to validate the efficiency of the installed shielding. Thefocus lied on the characterisation of the count rate in the neutron capture energy window. Anestimation of the background rate is presented and compared to the rate obtained in STEREO.At the current state of the analysis the background of accidental coincidences in STEREO is aminor contribution compared to the muon induced correlated background. In addition a seriesof MCNP simulations was performed to determine the impact of a beamtube removal in thevicinity of STEREO on the overall reactor-related background situation. The beamtube wasclosed by a dedicated shielding, optimised for background reduction for STEREO, which couldnot be reinstalled after removal of the tube. A new shielding at the end of the former beamtubewas proposed by the ILL. Its shielding effect was studied with MCNP and compared tothe previous configuration in order to assess whether the new shielding suffices or needs to beimproved. According to these simulations the background situation is expected to improve.Finally a procedure is proposed and applied for the analysis of the energy calibration ofthe STEREO detector. The procedure is designed to be applicable to all available calibrationsources and to minimise systematic uncertainties. It can be used to adjust parameters in theexisting Geant4-based simulation of the detector, developed by the collaboration, by comparisonto measured data and later to determine the energy scale with the required precision of < 2%
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Ma, Wing Yan. "Five sample joint neutrino/antineutrino oscillation analysis in T2K." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58946.
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This thesis describes a simultaneous fit to all five of the far detector oscillation samples analysed to date (FHC/RHC 1Rmu, FHC/RHC 1Re and FHC nue CC1pi+) using T2K data taken from 2009-2017 with \sci{1.47}{21}~POT in neutrino mode and \sci{0.76}{21}~POT in antineutrino mode. The aim of this analysis is to search for CP violation by setting limits on \dcp and measure the oscillation parameters \sonethree, \stwothree and \Dm232. The T2K (Tokai to Kamioka) experiment is a long-baseline accelerator neutrino oscillation experiment that is designed to make precision measurements of neutrino oscillation by observing numu disappearance and nue appearance. A numu beam is produced using a 30 GeV proton beam at the J-PARC and is detected by the near detector complex, ND280, and by the far detector, Super-Kamiokande, which is 295 km away from J-PARC. The far detector and one of the near detectors are located in an off-axis direction to the neutrino beam centre, resulting a narrow neutrino energy peak of 0.6 GeV and where the numu survival probability is expected to be minimal (or maximal nue appearance probability). The neutrino fluxes and their uncertainties at the near and far detector are predicted by the Monte Carlo simulation tuned with data from external hadron production experiments. The uncertainties of the neutrino flux parameters and certain neutrino interactions parameters at the far detector are reduced by the measurement at the off-axis near detector. Since the last analysis there has been improvement to event reconstructions at SK which results in 20% increase in nue increased purity in the 1R muon samples. Using data taken from 2009-2017, we observed 240 mu-like, 74 e-like, 15 nue CC1pi+ -like events in neutrino mode, and 68 mu-like, 7 e-like events in antineutrino mode. Confidence intervals for delta CP are produced using the Feldman-Cousins method, and confidence intervals of the other oscillation parameters are produced using the constant delta chi square method. The best-fit oscillation parameter values are found to be consistent with previous official results while giving tighter constraints. There is a first indication of CP conservation in neutrino sector excluded at 2 sigma level. The results are also presented showing the correlations that exist between the oscillation parameters.
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Backhouse, Christopher James. "Measuring neutrino oscillation parameters using ν_mu disappearance in MINOS." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:8d074071-fdf4-4d3e-a503-4d8a17b9e8e3.
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MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716 m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the "atmospheric" neutrino oscillation parameters (Δm2atm and sin22θatm). The oscillation signal consists of an energy-dependent deficit of vμ interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the vμ-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the vμ-disappearance analysis, incorporating this new estimator were: Δm2 = 2.32+0.12-0.08 x 10-3eV2 sin22θ > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly V‾μ beam, yielded somewhat different best-fit parameters Δ‾m2 = (3.36+0.46-0.40 (stat.}) ± 0.06(syst.)) x 10-3eV2, sin22‾θ =0.86+0.11-0.12(stat.) ± 0.01(syst.). The tension between these results is intriguing, and additional antineutrino data is currently being taken in order to further investigate this apparent discrepancy.
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Elevant, Jessica. "CP-violation in Supernova Neutrino Oscillations." Thesis, Linköpings universitet, Teoretisk Fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-109922.
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It is astonishing both how little and how much we know about neutrinos. On one hand, the neutrino is the second most abundant particle in our Universe. Neutrinos may be created in the Sun, core collapse supernovae, cosmic rays, geological background radiation, supernova remnants and in the Big Bang. On the other hand, they have unimaginably small masses and are unwilling to react with their surroundings. Because of their abundance and their inclination to show us physics beyond the standard model of particle physics, neutrinos are hoped to carry yet unknown information of the Universe. However, it will take some effort and time to persuade the neutrinos to tell us what they know. Among the things we do not yet know of the neutrinos, is the -phase in the neutrino mixing matrix. If is in fact non-zero, neutrino flavour oscillations violate CP-symmetry. Also, if neutrino masses are introduced in the standard model through the See-Saw mechanism and if leptogenesis is a valid theory, CP-violation in neutrino oscillations could help explain why our Universe has no antimatter even though equal amounts of matter and antimatter should have been created at the Big Bang. In this thesis, we investigate the flavour evolution of supernova neutrinos. We present the full Hamiltonian in the flavour basis for our system and identify how the different contributions affect the evolution and in which environment. We also present a theoretical motivation from [1, 2] as to how a non-zero -phase affects the flavour evolution and the final energy spectra. The analytical conclusion is that it has no impact under the assumptions made in our analysis. Thus, the -phase may not be measurable from supernova neutrinos.
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Chung, Jin-Hyuk. "Search for neutron oscillation and study of neutrino reaction rates using multiprong events in Soudan 2 /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2001.
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Thesis (Ph.D.)--Tufts University, 2001.Adviser: W. Anthony Mann. Submitted to the Dept. of Physics. Includes bibliographical references (leaves 125-130). Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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Thornewell, Peter Michael. "³He neutral current detectors for the Sudbury Neutrino Observatory." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343004.
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Basto, Gonzalez Victor Saul 1977. "Procura de indícios de neutrinos estéreis nos experimentos IceCube e KATRIN." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276982.
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Orientador: Orlando Luis Goulart PeresTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Motivados pelos indícios experimentais da existência de um quarto neutrino, que surge nos dados de oscilações coletados nos experimentos de aparecimento e desaparecimento de neutrinos, e pela possibilidade teórica de explicar a pequena massa dos neutrinos através de dimensões extras grandes, fizemos análises em procura de vestígios destas duas motivações nos experimentos IceCube e KATRIN. A existência deste quarto neutrino implicaria 1) que existem mais neutrinos que os três tipos de neutrinos do Modelo Padrão da física de partículas, 2) que as interações deste novo neutrino não são descritas pelo Modelo Padrão, 3) que os parâmetros da mistura dos três tipos de neutrinos do Modelo Padrão seriam afetados pela mistura com este novo neutrino e 4) que a diferença dos quadrados das massas, ?m^{2}, associada a este neutrino seria grande, ?m^{2} ~1 eV^{2}. Usando os dados de neutrinos atmosféricos de IceCube, podemos indagar pela existência do quarto neutrino, pois para, ?m^{2} ~1 eV^{2} acontece uma conversão de sabor devida ao efeito de matéria sobre o neutrino no intervalo de energias analisado no IceCube. Assim, este efeito de matéria permite-nos pôr limites sobre os parâmetros que governam as oscilações de neutrinos estéreis. O experimento KATRIN procurará medir a massa do neutrino. Esta medida será feita analisando a cinemática dos elétrons emitidos no decaimento beta do Trítio que é uma medida independente do modelo físico, pois está fundamentada na conservação da energia. A presença de estados mais pesados, como os que existem quando neutrinos estéreis estão presentes, nos permitirá vincular estes neutrinos estéreis. Especificamente, analisamos em KATRIN indícios de um e dois neutrinos estéreis e também de dimensões extras grandes
Abstract: Motivated by the experimental evidence of the existence of a fourth neutrino, which arises from the data collected of neutrino oscillations in appearance and disappearance experiments, and by the theoretical possibility to explain the smallness of the mass of the neutrinos through large extra dimensions, we performed analyses in search of seeking indication of these two motivations in the IceCube and KATRIN experiments. The existence of this fourth neutrino would imply 1) that there are more types of neutrinos than the three types of neutrinos present in the Standard Model of particle physics, 2) that this new neutrino interactions are not described by the Standard Model, 3) that the parameters of the three neutrinos mixing would be affected by mixing with this new type of neutrino, and 4) that the squared-mass difference , ?m^{2} associated with this new neutrino would be large, , ?m^{2} ~1 eV^{2}. Using the atmospheric neutrino data from IceCube, we can investigate the existence of the fourth neutrino because a flavor conversion happens in the limit , ?m^{2} ~1 eV^{2} due to the effect of matter on the neutrino in the range of energies analyzed in the IceCube. Thus, this matter effect allows us to constrain the parameters that govern the sterile neutrino oscillations. The KATRIN experiment will seek to measure the neutrino mass. This measure will be performed by analyzing the kinematics of electrons emitted in the tritium beta decay, which is an independent measure of the physical model because it is based on energy conservation. The presence of heavier states such as those that exist when sterile neutrinos are present, will allow us to constrain these sterile neutrinos. Specifically, we analyze in KATRIN evidence of one and two sterile neutrinos and also of large extra dimensions
Doutorado
Física
Doutor em Ciências
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Gomes, Abner Leonel Gadelha. "Limites nos parâmetros do modelo de oscilação com decaimento de neutrinos usando os dados do experimento MINOS." Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/7509.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
We use the and produced from MINOS beam line that recently reported a disappearence analysis using their full data and combining the beam line and atmospheric neutrinos and antineutrinos events. We used their beam data analysis to constrain the neutrino lifetime under the oscillation plus decay framework. Our analysis reports 3 < 1:4 103 GeV=s, which corresponds to a decay lifetime 3=m3 > 2:4 1012 s=eV , improving a previous MINOS measurement who is 3=m3 > 2:1 1012 s=eV .
Usamos dados de e produzidos da linha de feixe do experimento MINOS publicados recentemente em uma análise de desaparecimento de neutrinos muônicos utilizando dados completos de neutrinos e antineutrinos da linha de feixe e atmosféricos. Estabelecemos limites sobre a razão tempo de vida por massa do neutrino para o modelo de oscilação com decaimento. Obtivemos da análise um limite superior de 3 < 1;4 103 GeV=s, que corresponde a um tempo de vida de 3=m3 > 2;4 1012 s=eV no limite inferior, melhorando a medida anterior do MINOS que era de 3=m3 > 2;1 1012 s=eV .
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Chang, Pi-Jung. "Double Chooz neutrino detector: neutron detection systematic errors and detector seasonal stability." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16861.
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Doctor of PhilosophyDepartment of Physics
Glenn Horton-Smith
In March 2012, the Double Chooz reactor neutrino experiment published its most precise result so far: sin[superscript]2 2theta13 = 0.109 +/- 0.030(stat.) +/- 0.025(syst.). The statistical significance is 99.8% away from the no-oscillation hypothesis. The systematic uncertainties from background and detection efficiency are smaller than the first publication of the Double Chooz experiment. The neutron detection efficiency, one of the biggest contributions in detection systematic uncertainties, is a primary topic of this dissertation. The neutron detection efficiency is the product of three factors: the Gd-capture fraction, the efficiency of time difference between prompt and delayed signals, and the efficiency of energy containment. [superscript]252 Cf is used to determine the three factors in this study. The neutron detection efficiency from the [superscript]252 Cf result is confirmed by the electron antineutrino data and Monte Carlo simulations. The systematic uncertainty from the neutron detection efficiency is 0.91% used in the sin[superscript]2 2theta13 analysis. The seasonal variation in detector performance and the seasonal variations of the muon intensity are described in detail as well. The detector stability is confirmed by observation of two phenomena: 1) the [electron antineutrino] rate, which is seen to be uncorrelated with the liquid scintillator temperature, and 2) the daily muon rate, which has the expected correspondence with the effective atmospheric temperature. The correlation between the muon rate and effective atmospheric temperature is further analyzed in this thesis to determine the ratio of kaon to pion in the local atmosphere. An upper limit on instability of the neutron detection efficiency is established in the final chapter. The systematic error, 0.13%, from the relative instability is the deviation of the calibration runs. This thesis concludes with the potential systematic errors of neutron detection efficiency and estimation of how these potential systematic errors affect the result of sin[superscript]2 2theta13.
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Murakami, Akira. "Measurement of Neutrino Oscillation Parameters with the Precise Neutrino Flux Prediction in the T2K Experiment." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/175122.
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Sonley, Thomas John. "A measurement of the atmospheric neutrino flux and oscillation parameters at the Sudbury Neutrino Observatory." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/52783.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 119-121).
Through-going muon events are analyzed as a function of their direction of travel through the Sudbury Neutrino Observatory. Based on simulations and previous measurements, muons with a zenith angle of 1 < cos([theta]zenith) < 0:4 are selected as atmospheric neutrino-induced muons. A two-neutrino analysis of these events agrees with the oscillation parameters observed by the Super Kamiokande and Minos experiments, and places 2-D limits of [delta]m2 23 = 1:8+7:1 ??1:1 103 eV2 at the 68% confidence level, and sin2(2[theta]23) > 0:33 at the 90% confidence level. In addition, the flux of atmospheric neutrinos is measured in 1-D with a 68% confidence level to be 1:24+0:11 0:10 times the prediction of the BARTOL group based on SNO data alone, and 1:27+/-0.09 times the prediction when the oscillation parameters are constrained by the Super Kamiokande and Minos results.
by Thomas John Sonley.
Ph.D.
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Kikawa, Tatsuya. "Measurement of Neutrino Interactions and Three Flavor Neutrino Oscillations in the T2K Experiment." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/195958.
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Ferchichi, Chiraz. "Study of neutrino interactions in the near detector of T2K." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112106.
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L’expérience T2K étudie les propriétés des neutrinos, en particulier le phénomène d’oscillation des neutrinos. Se déroulant au Japon, elle utilise un faisceau de neutrinos muoniques produit par le complexe d’accélérateur J-PARC, un détecteur proche, ND280 sur le site même de J-PARC pour caractériser le faisceau, et un détecteur lointain, Super-Kamiokande situé à 295 km pour mesurer les oscillations de neutrinos. Le détecteur proche permet également d’étudier les interactions des neutrinos et cette thèse porte sur la mesure des sections efficaces de diffusion profondément inélastique des neutrinos muoniques.Le manuscrit introduit d’abord la physique des neutrinos, puis l’expérience T2K et en particulier les chambres à projection temporelles du détecteur proche, en insistant sur la vérification de la qualité des données, dont j’avais la charge. L’analyse porte sur les données de T2K enregistrées jusqu’en 2013. La sélection d’interactions de neutrinos muoniques par courant chargé est ensuite présentée, ainsi qu’une étude préliminaire de la sélection d’interactions de neutrinos muoniques par courant chargé avec production d’un pion neutre. Un critère portant sur la multiplicité des traces permet d’enrichir le premier lot en interactions correspondant à une diffusion profondément inélastique de neutrinos. Finalement un ajustement, validé d’abord sur des données simulées, permet d’extraire les sections efficaces de diffusion profondément inélastique des neutrinos muoniquesThe T2K experiment studies the properties of neutrinos, particularly neutrino oscillations. It takes place in Japan and uses a muonic neutrino beam produced by the J-PARC accelerator complex, a near detector, ND280 on the J-PARC site in order to characterise the beam, and a far detector, Super-Kamiokande 295 km away in order to measure the neutrino oscillations. The near detector is also used to study the neutrino interactions and the goal of this thesis is the measurement of muonic neutrino deep inelastic scattering cross sections.The thesis first introduces neutrino physics, then the T2K experiment and more particularly the time projection chambers of the near detector, and its data quality checking that I was in charge of. The analysis is based on the T2K data recorded until 2013. The selection of charged current muonic neutrino interactions is then presented, as well as a preliminary study of the selection of charged current muonic neutrino interactions with the production of a neutral pion. A criterion on track multiplicity allows enriching the former sample in interactions corresponding to a neutrino deep inelastic scattering. Finally a fit, first validated on simulated data, allows the extraction of the muonic neutrino deep inelastic scattering cross sections
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Ballett, Peter Alexander. "Probing leptonic flavour with future long-baseline neutrino oscillation experiments." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/7745/.
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Over the last 50 years, the study of the properties of neutrinos has unveiled a number of surprising facts that necessitate physics beyond the standard model. We now know that neutrinos are not only massive, but that there is a non-trivial alignment between the mass and flavour bases, inducing flavour changing transitions known as neutrino oscillations. Understanding the neutrino sector is a crucial first step in our attempts to extend our current theories of fundamental physics, and studies of neutrino oscillation provide us with a unique tool to probe these elusive particles. In this thesis, we assess the potential of the next generation of neutrino oscillation experiments to probe physical effects both within and beyond the current neutrino flavour paradigm: resolving existing unknowns, and constraining the correlations induced by theories of leptonic flavour.
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Maesaka, Hirokazu. "Evidence for muon neutrino oscillation in an accelerator-based experiment." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144603.
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Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第11852号
理博第2945号
新制||理||1441(附属図書館)
23632
UT51-2005-N686
京都大学大学院理学研究科物理学・宇宙物理学専攻
(主査)教授 西川 公一郎, 教授 今井 憲一, 助教授 中家 剛
学位規則第4条第1項該当
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Ching, Ping-pui, and 程炳沛. "Constraining neutrino oscillation parameters [th]12 and [d]m212 with ashort baseline reactor anti-neutrino experiment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B32048701.
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Kale, Sayi Kenny. "Study of the cosmic muon-induced background for the theta 13 angle in the Double Chooz neutrino oscillation experiment." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAE008.
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L’expérience Double Chooz, située sur le site de la centrale nucléaire de Chooz dans la région des Ardennes en France, étudie la disparition des antineutrinos. Le but principal de l’expérience est de mesurer avec une grande précision l’amplitude d’oscillation sin2 2θ13 des antineutrinos émis par les deux réacteurs de la centrale de Chooz. La précision de cette mesure dépend fortement d’une connaissance précise des taux et de la forme des spectres des bruits de fond qui contaminent la sélection finale des antineutrinos en particulier dans la gamme d’énergie où l’oscillation des neutrinos est attendue. Nous avons étudié dans la présente thèse le bruit de fond d’origine cosmique dans l’expérience Double Chooz. En effet, les muons cosmiques traversant les détecteurs ou interagissant dans le voisinage immédiat sont la principale source de bruit de fond observés dans l’expérience Double Chooz. Deux types de bruits de fonds sont analysés et présentes dans cette thèse : les neutrons rapides (FN) et la double capture de neutrons (DnC). Des techniques d’identification dédiées ont été développées pour chacun de ces bruits de fond et, par conséquent, les formes spectrales et les taux associés ont été́ déterminés. Les valeurs obtenues dans le cadre de ce travail servent de paramètres d’entrée dans le fit final d’où la valeur de θ13 est extraite. La dernière mesure publiée par la collaboration Double Chooz est sin2 2θ13 = 0.119 ± 0.016The Double Chooz experiment is- a reactor antineutrino disappearance experiment located on the site of the Chooz nuclear power plant in the Ardennes region in France. The principal aim of the experiment is a high precision measurement of the oscillation amplitude sin2 2θ13 of the antineutrinos emitted from the two reactor cores of the Chooz power plant. The robustness and accuracy of this measurement depends strongly on a precise knowledge of the rates and spectral shapes of the backgrounds that contaminate the antineutrinos selection over the neutrino oscillation expected region. We have studied in the present thesis the muon induced background in the Double Chooz experiment. Indeed, cosmic muons crossing the detectors or interacting in the neighborhood constitute the main source of background events encountered in Double Chooz. Two distinct backgrounds analysis are presented in this thesis: fast neutrons (FN) and double capture of neutrons (DnC). Dedicated identification techniques have been developed for each of these backgrounds and, consequently, the associated spectral shapes and rates have been determined. The values obtained in this work serve as inputs in the final fit whence the θ13 value is extracted.The latest measurement released by the Double Chooz collaboration is sin2 2θ13 = 0.119 ± 0.016$
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Ching, Ping-pui. "Constraining neutrino oscillation parameters [th]12 and [d]m212 with a short baseline reactor anti-neutrino experiment." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B32048701.
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Smith, Christopher Bernard. "Calibration of the MINOS detectors and extraction of neutrino oscillation parameters." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397794.
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Olla, Mattias. "Regularising IR divergences in neutrino oscillation amplitudes with a massless mediator." Thesis, KTH, Fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-233753.
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Jiang, Miao. "Study of the neutrino mass hierarchy with the atmospheric neutrino data collected in Super-Kamiokande IV." Kyoto University, 2019. http://hdl.handle.net/2433/242899.
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Meng, Yue. "The Daya Bay Reactor Neutrino Experiment." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/50534.
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The Daya Bay reactor neutrino experiment is a high sensitivity experiment designed to determine the last unknown neutrino mixing angle $theta_{13}$ by measuring disappearance of reactor antineutrinos emitted from six 2.9 $GW_{th}$ reactors at the Daya Bay Nuclear Power Station. There are eight identical Gd-loaded liquid scintillator detectors deployed in two near (flux-weighted baseline 512 $m$ and 561 $m$) and one far (1579 $m$) underground experimental halls to detect the inverse beta decay interaction. This dissertation describes the Daya Bay Experiment and individual contributions to this experiment.
Chapter 1 reviews the history of the neutrino and the neutrino oscillation phenomena. The reactor based neutrino experiments in different times are described in this chapter in detail. It presents the motivation of the Daya Bay Experiment. In Chapter 2, the neutrino detection method and the $theta_{13}$ relative measurement method are introduced. This chapter focuses on the design of the Daya Bay Experiment, including antineutrino detector, calibration system, muon veto system and muon tagging system. Chapter 3 shows the design, development, construction, and assembly of Muon Pool PMT calibration system, and presents an algorithm of calculating the muon pool PMT timing offset values. Chapter 4 focuses on the manufacture, installation and commissioning of RPC HV system. Chapter 5 presents the analyses of the radioactive isotopes induced by comic muons. The Daya Bay detector energy response model is also described in detail.
The relative rate analysis results exclude a zero value from $sin^22theta_{13}$ with a significance of 7.7 standard deviation using 139 days of data, 28909 (205308) antineutrino candidates which were recorded at the far hall (near halls) and shows $sin^22theta_{13} = 0.089pm0.011$ in a three-neutrino framework. A combined analysis of the $overline nu_e$ rates and energy spectra based on the detector energy response model improved measurement of the mixing angle $sin^22theta_{13} = 0.090^{+0.008}_{-0.009}$ by using 217 days of data, 41589 (203809 and 92912) antineutrino candidates were detected in the far hall (near halls). Also the first direct measurement of the $overline nu_e$ mass-squared difference $|Delta m^2_{ee}|= (2.59^{+0.19}_{-0.20})times10^{-3}$ $eV^2$. It is consistent with $|Delta m^2_{mumu}|$ measured by muon neutrino disappearance, supporting the three-flavor oscillation model.Ph. D.
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Tolich, Kazumi. "Measurement of neutrino oscillation parameters and investigation of uranium and thorium abundances in the earth using anti-neutrinos /." May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Petyt, David Anthony. "A study of parameter measurement in a long-baseline neutrino oscillation experiment." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284338.
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Adamson, Philip. "An LED calibration system for the MINOS long baseline neutrino oscillation experiment." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394342.
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Sorri, Antti. "Active-sterile neutrino oscillation and lepton asymmetry generation in the early universe." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/mat/fysik/vk/sorri/.
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Wren, Steven. "Neutrino mass ordering studies with IceCube-DeepCore." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/neutrino-mass-ordering-studies-with-icecubedeepcore(70414fde-3bef-4028-877b-5e1e86b2165d).html.
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The IceCube Neutrino Observatory at the South Pole is the world's largest neutrino detector with over 1km^3 of instrumented Antarctic ice. While it has been primarily designed to observe astrophysical neutrinos, this size also allows it to collect vast quantities of atmospheric neutrinos. These high-statistics datasets allow for measurements of the properties of neutrinos, in particular the phenomena of neutrino oscillation. One of the outstanding questions in this field is that of the neutrino mass ordering (NMO). The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy extension to IceCube for which a determination of the NMO is a priority science goal. The current low-energy atmospheric neutrino experiment at the South Pole, DeepCore, has been successfully collecting data since 2011. In this thesis the potential of this existing data to determine the NMO has been explored. While it was not expected to have a large sensitivity, this work has explored a Feldman-Cousins treatment for converting the delta-chi^2 between the two discrete mass ordering hypotheses into the standard Gaussian significance metric. Using 2.7 years of data from the DeepCore detector, the inverted mass ordering was preferred at the level of 0.05sigma. The second aspect of this thesis was to study the impact of the systematic uncertainties on the NMO determination. This particular analysis was actually statistics-limited and so the only impactful systematic uncertainties were the parameters that govern atmospheric neutrino oscillations, theta_23 and Deltam^2_31. Therefore, to improve the NMO results, these parameters were constrained by including the global information on them in the fits, yielding a new NMO sensitivity of 0.29sigma. This new global fit also yields measurements of the oscillation parameters of Deltam^2_32,NO=(2.443+/-0.037)e-3eV^2 and sin^2theta_23,NO=0.442+0.026-0.018 for the hypothesis of the normal mass ordering and Deltam^2_32,IO=(-2.510+/-0.036)e-3eV^2 and sin^2theta_23,IO=0.579+0.019-0.021 for the hypothesis of the inverted mass ordering. In addition to the work on the neutrino mass ordering, this thesis also investigated two issues related to predictions of the flux of atmospheric particles. The first related to the treatment of the predictions of the atmospheric neutrino flux, provided in binned tables. Crucially, these contain values representative of the integral of the flux across that bin and so an integral-preserving interpolation must be used. One such method will be presented along with a discussion of how it performs in the two-dimensional case of the atmospheric neutrino flux. The second issue related to quantifying uncertainties on the background muon distributions observed with the IceCube detector coming from the uncertainties on the initial cosmic ray flux. This involved performing a global fit on the available cosmic ray flux measurements and then propagating these uncertainties in to the muon distributions. To finalise this section, the exact manner in which these uncertainties can be included in the physics analyses of IceCube will be discussed.