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Řezníček, Pavel ; Dlugoš, Jozef (referee) ; Zháňal, Lubor (advisor)
This diploma thesis deals with possibility of using a mobile phone to measure vehicle dynamics and determine the accuracy of this measurement. In the research part, it is first mentioned what methods are used to produce sensors for mobile phones. Next, a description of individual sensors that can be used for vehicle dynamics measurement, the principle by which the sensors record measured values and their inaccuracies. The practical part shows with which professional device the accuracy of the mobile phone is compared, how data can be collected from both devices and how the comparison measurement was performed. This section also describes the ways in which the measured data of the mobile phone can be improve for better accuracy, and finally the comparison of the measured values from both devices from different points of view.
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Neutral pion identification at Future Circular Collider
Haviernik, Matej ; Faltová, Jana (advisor) ; Řezníček, Pavel (referee)
Future Circular Collider (FCC) is a 100 km long particle collider to be built around the year 2040 in the CERN laboratory. The first stage of operation is going to be a lepton collider FCC-ee which aims to test the Standard model with unprecedented precision at maximal central energies of 365 GeV. Neutral pions originating from such collisions are crucial for reconstructions of particles such as the τ lepton and their identification poses a challenge for detectors. Neutral pions decay almost immediately into a pair of photons separated by a small angle and can be easily misidentified as a single photon. We should be able to distinguish the signal of a neutral pion from the signal of a single photon with a fine segmented calorimeter. In the thesis we will work with the FCC-ee noble liquid calorimeter design. The main goal of the thesis is to understand the geometry of the calorimeter planned for FCC-ee experiment and investigate the options offered by multivariate analysis methods for the reconstruction and identification of neutral pions against a single photon background. 1
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Laser pulse and source response on silicon detectors
Sater, Adrián ; Kodyš, Peter (advisor) ; Řezníček, Pavel (referee)
This thesis is focused on introduction on project CERN and ATLAS and on apparatus used for detection of particles. Moreover, thesis describes upgrades of detection apparatus, whose goal is to increase performance of the ATLAS detector(ATLAS Upgrade), these upgrades should result in increase of centre of mass energy in collisions and luminosity in collider, thus enabling new discoveries. Thesis also describes operation principle of silicon detectors and their utilization in ATLAS and ATLAS Upgrade. Subsequently, in third part of the thesis principle of measurement, data acquisition from measurements and data analysis is explained. The calibration of modules done before measurements is also described. In the last part, thesis focuses on describing various tests used for testing silicon sensors and their application in laboratories of Institute of Particle and Nuclear Physics in Prague. Unfortunately, thesis does not contain practical part in the form of tests on new chips as they were not ready until February 2022 and also the laboratory for laser tests was disassembled due to reconstruction. 1
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Řezníček, Pavel ; Dlugoš, Jozef (referee) ; Zháňal, Lubor (advisor)
This diploma thesis deals with possibility of using a mobile phone to measure vehicle dynamics and determine the accuracy of this measurement. In the research part, it is first mentioned what methods are used to produce sensors for mobile phones. Next, a description of individual sensors that can be used for vehicle dynamics measurement, the principle by which the sensors record measured values and their inaccuracies. The practical part shows with which professional device the accuracy of the mobile phone is compared, how data can be collected from both devices and how the comparison measurement was performed. This section also describes the ways in which the measured data of the mobile phone can be improve for better accuracy, and finally the comparison of the measured values from both devices from different points of view.
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Measurement of the B0 meson lifetime at ATLAS detector
Řezníček, Pavel ; Doležal, Zdeněk (advisor) ; Cvach, Jaroslav (referee) ; Catmore, James Richard (referee)
Title: Measurement of the B0 d meson lifetime at ATLAS detector Author: Pavel Řezníček Department: Institute of Particle and Nuclear Physics Supervisor of the doctoral thesis: Dr. Zdeněk Doležal Supervisor's e-mail address: Zdenek.Dolezal@mff.cuni.cz Abstract: The lifetime of B0 d mesons is determined from their decays B0 d → J/ψK∗0 reconstructed in ATLAS experiment at the LHC using pp collision data at a center-of-mass energy of 7 TeV and corresponding to integrated luminosity of 40 pb−1 . The lifetime, extracted from the simultaneous unbinned maximum likelihood mass-lifetime fit, is 1.51±0.04 (stat.)±0.04 (syst.) ps. A total number of 2750±90 (stat.) signal B0 d decays are observed in the measurement, with a fit- ted B0 d mass of 5363.7 ± 1.2 (stat.) MeV. Both the extracted B0 d meson mass and lifetime are within the determined errors consistent with the world average values. Although the achieved precision is still significantly lower than the one of the world average value, the measurement successfully tested the feasibility of the fit-method and allowed to cross-check ATLAS detector performance. Keywords: CERN, LHC, ATLAS, B-physics, B-hadron, Lifetime
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Silicon detector response and its simulation
Martausová, Lýdia ; Kodyš, Peter (advisor) ; Řezníček, Pavel (referee)
The ATLAS experiment is currently undergoing a modernization, called the ATLAS Upgrade. Nowadays, simulations are an important part of planning new detectors and their modernization. They help us optimize their design before production and later verify the results obtained from the experiment. This work is focused on the simulation of edge eects on a silicon strip detector using a framework Allpix2 . In the beginning, we had no information, that any edge eects or even any irregular eects, is possible to simulate in Allpix2 . We rst veried that in the case of a simple irregular electric eld. We had at our disposal measurements performed at the Institute of Particle and Nuclear Physics, with which we compared the simulation. The signal obtained from the edge strip has dierent behaviour and is wider than the other strips. Therefore, we extended the electric eld of the edge strip in the simulation and modied it in various ways. 1
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Measurement of the B0 meson lifetime at ATLAS detector
Řezníček, Pavel
Title: Measurement of the B0 d meson lifetime at ATLAS detector Author: Pavel Řezníček Department: Institute of Particle and Nuclear Physics Supervisor of the doctoral thesis: Dr. Zdeněk Doležal Supervisor's e-mail address: Zdenek.Dolezal@mff.cuni.cz Abstract: The lifetime of B0 d mesons is determined from their decays B0 d → J/ψK∗0 reconstructed in ATLAS experiment at the LHC using pp collision data at a center-of-mass energy of 7 TeV and corresponding to integrated luminosity of 40 pb−1 . The lifetime, extracted from the simultaneous unbinned maximum likelihood mass-lifetime fit, is 1.51±0.04 (stat.)±0.04 (syst.) ps. A total number of 2750±90 (stat.) signal B0 d decays are observed in the measurement, with a fit- ted B0 d mass of 5363.7 ± 1.2 (stat.) MeV. Both the extracted B0 d meson mass and lifetime are within the determined errors consistent with the world average values. Although the achieved precision is still significantly lower than the one of the world average value, the measurement successfully tested the feasibility of the fit-method and allowed to cross-check ATLAS detector performance. Keywords: CERN, LHC, ATLAS, B-physics, B-hadron, Lifetime
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Study of the rare B-meson decays with the ATLAS experiment
Biroš, Marek ; Řezníček, Pavel (advisor) ; Scheirich, Daniel (referee)
Title: Study of the rare B-meson decays with the ATLAS experiment Author: Marek Biroš Institute: Institute of Particle and Nuclear Physics Supervisor: RNDr. Pavel Řezníček, Ph.D., Institute of Particle and Nuclear Physics Abstract: The rare B0 d → K∗0 (892) μμ decay is one of the B-physics channels sensitive to Beyond Standard Model effects. The potential deviation from Standard Model predictions could be observed in the angular distribution of this decay. The work compiles several sub-tasks at the initial stage of this complex analysis: decay angles fit validation and signal event preselection. The fit functions used in the analysis are verified on generated toy Monte Carlo data. Ranges of parameters, for which are these functions positive, are established and within this parametric space, the testing of possible intrinsic fit biases is evaluated. A dependence of the fit bias with respect to the collected number of events (expected in Run 2 as well as at HL-LHC) and to the different signal-to- background ratio is studied. The second part of the thesis deals with processing of raw reconstructed data from the detector into n-tuples resulting in a more compact dataset that would be used in the final analysis. Within the process, baseline cuts are applied in order to minimize size of final datasets by reducing...
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