رسالة جامعية
The photon reconstruction and identification in the CMS detector. Higgs boson search in the two photons decay channel with the CMS experiment at LHC ; La reconstruction et l'identification des photons dans l'expérience CMS au LHC. Applications à la recherche de bosons de Higgs dans le canal H $\rightarrow \gamma\gamma$
| العنوان: | The photon reconstruction and identification in the CMS detector. Higgs boson search in the two photons decay channel with the CMS experiment at LHC ; La reconstruction et l'identification des photons dans l'expérience CMS au LHC. Applications à la recherche de bosons de Higgs dans le canal H $\rightarrow \gamma\gamma$ |
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| المؤلفون: | Brun, Hugues |
| المساهمون: | CMS, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard - Lyon I, Susan Gascon-Shotkin(s.gascon-shotkin@ipnl.in2p3.fr) |
| المصدر: | https://theses.hal.science/tel-00916276Test ; Physique des Hautes Energies - Expérience [hep-ex]. Université Claude Bernard - Lyon I, 2012. Français. ⟨NNT : ⟩. |
| بيانات النشر: | HAL CCSD |
| سنة النشر: | 2012 |
| المجموعة: | HAL Lyon 1 (University Claude Bernard Lyon 1) |
| مصطلحات موضوعية: | Higgs boson, CMS experiment, electromagnetic calorimeter, neural network, diphoton, boson de Higgs : expérience CMS, LHC, calorimètre électromagnétique, réseau de neurones, diphotons, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] |
| الوصف: | The Standard Model of particle physics successfully explains the majority of experimental high energy physics data. The masses of the W and Z, the vector bosons of the electroweak theory, are explained with a spontaneous breaking of the gauge symmetry. This symmetry breaking is performed, using the Higgs mechanism, by introducing a new scalar field, whose quantum, the Higgs boson, is intensively searched at LHC. Theoretical considerations suggest that the mass of the Higgs boson should be lower than 1 TeV/c$^2$ and the fit of precision electroweak measurements constrains the Higgs boson mass to be less than 158 GeV/c$^2$. Direct searches at LEP have excluded the Higgs boson with masses lower than 114.4 GeV/c$^2$, and direct searches at the Tevatron have led to an exclusion of masses between 147 and 180 GeV/c$^2$. The fit of precision electroweak measurements constrains the Higgs boson mass to be less than 158 GeV/c$^2$ (all these limits are at the 95% confidence level). The photon reconstruction in CMS is detailed in this thesisand its understanding with the first LHC data will be shown. Because of the narrow Higgs resonance, a particular attention as to be put on the photon energy resolution. Neutral pions decaying in two photons are the main background to the prompt photons: the possibility of using a neural network based on shower shape in ECAL is studied. These neutral mesons are also one important background to the photons from Higgs boson decay. The improvement of the photon identification, thanks to a cut on the neural network output, is evaluated: the result in term of limits for the first 1.6fb$^1$ of 2011 data is presented. ; Le Modèle Standard de la physique des particules explique avec succès les données expérimentales. L'origine de la masse des bosons W et Z est expliquée à l'aide du mécanisme de Higgs qui permet de briser la symétrie de jauge de l'interaction électro-faible. Cependant ce mécanisme prédit l'existence d'une particule, appelée le boson de Higgs, qui n'a pas été observée pour ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | French |
| العلاقة: | tel-00916276; https://theses.hal.science/tel-00916276Test; https://theses.hal.science/tel-00916276/documentTest; https://theses.hal.science/tel-00916276/file/TheseFinal3.pdfTest |
| الإتاحة: | https://theses.hal.science/tel-00916276Test https://theses.hal.science/tel-00916276/documentTest https://theses.hal.science/tel-00916276/file/TheseFinal3.pdfTest |
| حقوق: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.73CFBBA1 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |