Simulace a analýza testů senzorů pro vrcholový detektor Belle II

Předložená diplomová práce popisuje vývoj a analýzu simulace, rekonstruckce a alignmentu pro testování sensorů vrcholového detektoru Belle II a proceduru pro alignment samotného vertexového detektoru. Prvním cílem práce bylo vytvoření a validace nástrojů pro analýzu testů sensorů přímo v prostředí společného softwarového rámce experiment Belle II. Druhým cílem byla příprava procedury pro alignment kompletního vertexového detektoru, která je nedílnou součástí procesu kalibrace. První část práce se věnuje experiment Belle II, vrcholovému detektoru, experimentálnímu testu jeho sensorů a popisu společného softwarového prostředí. Zvolená aligmentovací procedura, Millepede II, a fitování pomocí General Broken Lines jsou teroreticky objasněny. Druhá část práce pak shrnuje software, který byl pro práci vyvinut nebo použit a výsledky, které byly s jeho pomocí dosaženy, s důrazem na alignment.This master thesis describes development and analysis of simulation, reconstruction and alignment for tests of Belle II vertex detector sensors as well as alignment procedure for the vertex detector itself. The first goal is to develop and test software tools which would allow analysis of sensor tests within common Belle II software framework. The second goal is to prepare the alignment chain for the vertex detector, being essential component of the detector calibration. First part of the thesis describes the Belle II experiment and its vertex detector, as well as the experimental beam test of the sensors and the common software framework. The theory behind the used alignment procedure utilizing Millepede II for alignment and General Broken Lines for track fitting is explained. Second part of the thesis then summarizes software tools developed or used and the results reached with these tools with emphasis on the alignment.Ústav částicové a jaderné fyzikyInstitute of Particle and Nuclear PhysicsMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

Time-dependent CP violation in B0 → ηc KS0 decays at the Belle experiment, Alignment of the Belle II detector

This thesis deals with two independent yet closely related topics. In the first part, a measurement of branching fraction and time-dependent CP violation in B0 → ηcK0 S, ηc → K0 SK± π∓ decays is performed. This decay allows access to sin 2ϕ1, where ϕ1 is an angle of the unitary triangle of the Cabibbo-Kobayashi- Maskawa quark mixing matrix. The measurement is based on the entire dataset of the Belle experiment, which consists of 772 × 106 B meson pairs collected at the KEKB e+ e− collider. The extracted mixing-induced and direct CP- violation parameters read sin 2ϕ1 ≃ S = 0.59 ± 0.17 (stat) ± 0.07 (syst) and A = 0.16 ± 0.12 (stat) ± 0.06 (syst), respectively. The measured product of branching fractions B(B0 → ηcK0 S) × B(ηc → K0 SK± π∓ ) is (9.8 ± 0.6 (stat) ± 0.4 (syst)±2.3 (int))×10−6 , where the last uncertainty accounts for interference with non-resonant background. The second part deals with the alignment of the vertex detector and the central drift chamber of the Belle II experiment at the SuperKEKB collider, which is a next-generation Super-B-Factory. With the new pixel detector and the presented alignment method, Belle II achieves approximately twice better impact parameter resolutions than Belle. The presented alignment procedure involves a simultaneous determination of about sixty thousand..

Time-dependent CP violation in B0 → ηc KS0 decays at the Belle experiment, Alignment of the Belle II detector

This thesis deals with two independent yet closely related topics. In the first part, a measurement of branching fraction and time-dependent CP violation in B0 → ηcK0 S, ηc → K0 SK± π∓ decays is performed. This decay allows access to sin 2ϕ1, where ϕ1 is an angle of the unitary triangle of the Cabibbo-Kobayashi- Maskawa quark mixing matrix. The measurement is based on the entire dataset of the Belle experiment, which consists of 772 × 106 B meson pairs collected at the KEKB e+ e− collider. The extracted mixing-induced and direct CP- violation parameters read sin 2ϕ1 ≃ S = 0.59 ± 0.17 (stat) ± 0.07 (syst) and A = 0.16 ± 0.12 (stat) ± 0.06 (syst), respectively. The measured product of branching fractions B(B0 → ηcK0 S) × B(ηc → K0 SK± π∓ ) is (9.8 ± 0.6 (stat) ± 0.4 (syst)±2.3 (int))×10−6 , where the last uncertainty accounts for interference with non-resonant background. The second part deals with the alignment of the vertex detector and the central drift chamber of the Belle II experiment at the SuperKEKB collider, which is a next-generation Super-B-Factory. With the new pixel detector and the presented alignment method, Belle II achieves approximately twice better impact parameter resolutions than Belle. The presented alignment procedure involves a simultaneous determination of about sixty thousand..

Časově závislé narušení CP symetrie v rozpadech B0 → ηc KS0 na experimentu Belle, Alignment detektoru Belle II

This thesis deals with two independent yet closely related topics. In the first part, a measurement of branching fraction and time-dependent CP violation in B0 → ηcK0 S, ηc → K0 SK± π∓ decays is performed. This decay allows access to sin 2ϕ1, where ϕ1 is an angle of the unitary triangle of the Cabibbo-Kobayashi- Maskawa quark mixing matrix. The measurement is based on the entire dataset of the Belle experiment, which consists of 772 × 106 B meson pairs collected at the KEKB e+ e− collider. The extracted mixing-induced and direct CP- violation parameters read sin 2ϕ1 ≃ S = 0.59 ± 0.17 (stat) ± 0.07 (syst) and A = 0.16 ± 0.12 (stat) ± 0.06 (syst), respectively. The measured product of branching fractions B(B0 → ηcK0 S) × B(ηc → K0 SK± π∓ ) is (9.8 ± 0.6 (stat) ± 0.4 (syst)±2.3 (int))×10−6 , where the last uncertainty accounts for interference with non-resonant background. The second part deals with the alignment of the vertex detector and the central drift chamber of the Belle II experiment at the SuperKEKB collider, which is a next-generation Super-B-Factory. With the new pixel detector and the presented alignment method, Belle II achieves approximately twice better impact parameter resolutions than Belle. The presented alignment procedure involves a simultaneous determination of about sixty thousand...Tato práce se zabývá dvěma nezávislými, avšak úzce souvisejícími tématy. V první části se je změřen větvící poměr a časově závislé narušení CP syme- trie v rozpadech B0 → ηcK0 S, ηc → K0 SK± π∓ . Tento rozpad umožňuje získat přístup k sin 2ϕ1, kde ϕ1 je úhel unitárního trojúhelníku Cabibbo-Kobayashi- Maskawovy kvarkové směšovací matice. Měření je založeno na celém souboru dat z experimentu Belle, který se skládá ze 772 × 106 párů B mezonů získaných na e+ e− urychlovači KEKB. Extrahované parametry časově závislého a přímého CP narušení jsou sin 2ϕ1 ≃ S = 0.59 ± 0.17 (stat) ± 0.07 (syst) a A = 0.16 ± 0.12 (stat) ± 0.06 (syst). Změřený součin větvících poměrů B(B0 → ηcK0 S) × B(ηc → K0 SK± π∓ ) je (9.8±0.6 (stat)±0.4 (syst)±2.3 (int))×10−6 , kde poslední nejistota zohledňuje interferenci s nerezonančním pozadím. Druhá část se zabývá alignmentem vrcholového detektoru a centrální drif- tové komory experimentu Belle II na urychlovači SuperKEKB, který je Super- B-Továrnou nové generace. S novým pixelovým detektorem a prezentovanou metodou alignmentu dosahuje Belle II přibližně dvakrát lepšího rozlišení im- paktních parametrů než Belle. Předložená alignmentovací procedura zahrnuje simultánní určení...Ústav částicové a jaderné fyzikyInstitute of Particle and Nuclear PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Vývoj křemíkového detektoru pro experiment Belle II

This bachelor thesis describes a simulation of the DEPFET pixel semiconductor detector. The DEPFET detector is a key part of a newly constructed Belle II particle detector being built in KEK, Japan. The simulation is made as a package for the basf2 framework, developed for the Belle II experiment. The goal of this thesis was to learn about the Belle II experiment, DEPFET pixel detector and the basf2 framework and to develop a simulation environment, depicting experimental setup at CERN's SPS accelerator in 2009. First part of this thesis describes the Belle II detector, the basf2 framework and summarizes basic information about silicon particle detectors, especially about the DEPFET technology. A task for the analysis of the data is to evaluate residuals after particle track fitting and cluster information in the pixel detector. Finally the simulation with thinned DEPFET sensor being developed for the Belle II is done

Simulation and analysis of tests of Belle II vertex detector sensors

This master thesis describes development and analysis of simulation, reconstruction and alignment for tests of Belle II vertex detector sensors as well as alignment procedure for the vertex detector itself. The first goal is to develop and test software tools which would allow analysis of sensor tests within common Belle II software framework. The second goal is to prepare the alignment chain for the vertex detector, being essential component of the detector calibration. First part of the thesis describes the Belle II experiment and its vertex detector, as well as the experimental beam test of the sensors and the common software framework. The theory behind the used alignment procedure utilizing Millepede II for alignment and General Broken Lines for track fitting is explained. Second part of the thesis then summarizes software tools developed or used and the results reached with these tools with emphasis on the alignment

Data quality monitors of vertex detectors at the start of the Belle II experiment

The Belle II experiment features a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e+e− collider at KEK in Tsukuba, Japan. The accelerator completed its first phase of commissioning in 2016, and the Belle II detector saw its first electron-positron collisions in April 2018. Belle II features a newly designed silicon vertex detector based on double-sided strip layers and DEPFET pixel layers. A subset of the vertex detector was operated in 2018 to determine background conditions (Phase 2 operation). The collaboration completed full detector installation in January 2019, and the experiment started full data taking. This paper will report on the final arrangement of the silicon vertex detector part of Belle II with a focus on online monitoring of detector conditions and data quality, on the design and use of diagnostic and reference plots, and on integration with the software framework of Belle II. Data quality monitoring plots will be discussed with a focus on simulation and acquired cosmic and collision data

Data quality monitors of vertex detectors at the start of the Belle II experiment

The Belle II experiment features a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric e+e− collider at KEK in Tsukuba, Japan. The accelerator completed its first phase of commissioning in 2016, and the Belle II detector saw its first electron-positron collisions in April 2018. Belle II features a newly designed silicon vertex detector based on double-sided strip layers and DEPFET pixel layers. A subset of the vertex detector was operated in 2018 to determine background conditions (Phase 2 operation). The collaboration completed full detector installation in January 2019, and the experiment started full data taking. This paper will report on the final arrangement of the silicon vertex detector part of Belle II with a focus on online monitoring of detector conditions and data quality, on the design and use of diagnostic and reference plots, and on integration with the software framework of Belle II. Data quality monitoring plots will be discussed with a focus on simulation and acquired cosmic and collision data