National Repository of Grey Literature 12 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Study of high energy cosmic gamma rays
Štefánik, Stanislav ; Nosek, Dalibor (advisor) ; Soustružník, Karel (referee) ; Tománková, Lenka (referee)
In this thesis, we present our two studies focused on the detection of cosmic γ-rays and the analysis of data from γ-ray observations. One study deals with the method of the Cherenkov transparency coefficient. This method is suitable for the detector calibration in experiments employing imaging atmo- spheric Cherenkov telescopes for the indirect detection of cosmic γ-rays. Us- ing rates of recorded air showers initiated by charged cosmic rays, the method aims at the monitoring of the atmospheric transparency to Cherenkov light and the calibration of the responses of Cherenkov telescopes. We present an extension of this method for the purposes of the Cherenkov Telescope Array observatory and demonstrate its feasibility using Monte Carlo simu- lations. Our other analysis utilizes more than 7 years of data from direct γ-ray observations by the Fermi Large Area Telescope. We describe in detail signal observed from the parts of the sky around the active galactic nuclei 1ES 0229+200 and Centaurus A. We report on the findings of new astro- physical sources of high energy photons and document spectral and temporal properties of their γ-ray fluxes. 1
Neutrino physics at NOvA experiment
Králik, Róbert ; Soustružník, Karel (advisor) ; Vorobel, Vít (referee)
Title: Neutrino physics at NOvA experiment Author: Róbert Králik Institute: Institute of Particle and Nuclear Physics Supervisor: RNDr. Karel Soustružník, Ph.D., Institute of Particle and Nuclear Physics Abstract: This thesis describes neutrino phenomenology, with special aim at the phenomenon of sterile neutrinos and its experimental study, particularly in the NOvA experiment. Its aim is to clearly and comprehensibly introduce sterile neutrinos in context of historical and present measurements and discoveries. A brief summary of neutrino history is shown, as well as the theory of neutrino oscillations, including a description of matter effects and the effect of adding sterile neutrinos on the oscillation probabilities. NOvA experiment is presented, describing the neutrino source, the detectors and the used particle identification methods. Different experiments for the study of sterile neutrinos are listed and shortly described, with special concentration on the NOvA experiment and its measurement via the neutral-current channel. A detailed description of the first NOvA sterile neutrino result is provided, as well as the aspects of NOvA's current sterile neutrino analyses. Keywords: neutrino, neutrino oscillations, sterile neutrinos, NOvA experiment 1
Studium vlastností neutrin pomocí NOvA detektoru
Jelínková, Zuzana ; Soustružník, Karel (advisor) ; Zálešák, Jaroslav (referee)
The NOνA experiment is a long-baseline neutrino oscillation experiment designed to measure electron neutrinos (νe) appearing in the NuMI beam, a muon neutrino (νµ) source at Fermilab. Its two detectors, Near and Far, are functionally identical active tracking calorimeters. This thesis is focused on the relative calibration of the Near Detector. The individual steps of the process, threshold, shadowing and attenuation calibration, are described. For the calibration, NOνA standardly uses cosmic muons. Alternative source, so called rock muons which are muons that originated from interactions of beam νµs with a rock surrounding the Near Detector, is introduced. The thesis guides through the development of selection criteria used to distinguish rock muon tracks from the data. Selected sample of rock muon tracks is used for the relative calibration and at each step the results are compared to the cosmic muons based calibration. The whole analysis is performed using simulated Monte Carlo data. 1
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).
Studium parametrů oscilací neutrin v experimentu NOvA
Nosek, Tomáš ; Soustružník, Karel (advisor) ; Leitner, Rupert (referee)
This thesis aims at the neutrino oscillations phenomena and the role of longbaseline neutrino oscillation experiments and NOνA in particular in oscillation parameters search. The standard formalism of 3 neutrinos model is described, NOνA experiment and its main features and physics goals (mixing angles θ13 and θ23, CP violation, the value of the CP phase δ and mass hierarchy determination) are introduced. The effects of media to neutrino propagation are explained and effective matter oscillation parameters are derived. The way to resolve the mass hierarchy exploiting matter effects in long-baseline neutrino oscillation experiments is depicted and consequent problems regarding the recent knowledge of oscillation parameters, i.e. δ-, θ13- and θ23-degeneracies, are discussed. In the last part GLoBES software is used to simulate NOνA results and to compute the estimated sensitivities to the mass hierarchy in case of 3 years ν run and 1.5ν+1.5ν years run in order to show the advantage of an earlier switch to antineutrino mode in mass hierarchy determination.
Chlad, Lukáš ; Kugler, Andrej (advisor) ; Soustružník, Karel (referee)
During the summer 2014, the HADES collaboration had the opportunity to measure pion collisions with different nuclei. These measurements were done with two objectives. The first being the investigations of hadrons with strange quarks and their behaviour at normal nuclear density. The analysis of this will concentrate specifically on φ meson and Λ baryon production. The focus on properties of baryonic resonances in the region of N(1520) and N(1535) formed the second objective. Special emphasis is put on beam line detectors which use different particle detection techniques. In particular, the scintillator based Hodoscope and diamond based Start detector will be discussed. There is also presented the analysis of π + p elastic scattering which is important for normalisation of the cross section of the reactions of interest. The measured elastic scattering yields are compared with dedicated simulations and previously published data. 1
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.
Top Quark Physics with the ATLAS Detector
Slovák, Radim ; Kvita, Jiří (advisor) ; Soustružník, Karel (referee)
In the presented diploma thesis we study the reconstruction of the top antitop system in proton-proton colisions with central mass energy 7 TeV de- livered by LHC accelerator at CERN to the ATLAS experiment. ALPGEN and MC@NLO generators are described as two main method of top antitop pairs simulations. We compare events simulated by generators to data from LHC. The background and selection criteria are summarized. Next we de- scribed various methods of the top antitop reconstruction. Finally the Z particle was also studied. 1
Study of heavy particle production at D0
Benedikt, Tomáš ; Soustružník, Karel (advisor) ; Žáček, Josef (referee)
This work is about properties of top quark and methods of their measurements, which took place at D0 detector. At the beginning the history of the quark model is summarized followed by introduction to D0 detector at Tevatron collider in the USA. The rest of the work is dedicated to methods of measurements of important top quark properties. The most of attention is paid to measurements of production cross section and top quark's mass. The following topics are decay width, determination of the mass difference between top and antitop quarks and determination od top quark's electrical charge. In the end the newest values of top quark's properties are summarized.

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