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Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS

This Master's thesis studies the same sign W bosons scattering process and aims to measure its cross section at the LHC using the proton-proton data at 8 TeV in the center of mass in the CMS experiment. This rare process is key in probing the nature of electroweak symmetry breaking and is sensi...

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Autor principal: Delannoy, Hugo
Lenguaje:fre
Publicado: 2017
Materias:
Acceso en línea:http://cds.cern.ch/record/2290840
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author Delannoy, Hugo
author_facet Delannoy, Hugo
author_sort Delannoy, Hugo
collection CERN
description This Master's thesis studies the same sign W bosons scattering process and aims to measure its cross section at the LHC using the proton-proton data at 8 TeV in the center of mass in the CMS experiment. This rare process is key in probing the nature of electroweak symmetry breaking and is sensitive to Beyond the Standard Model theories. In September 2013, both the ATLAS and the CMS experiments had yet to go further than preliminary studies with regards to the measurement of the cross section studied in this thesis. We hereby demonstrate that one can isolate the same sign W bosons scattering process from the other W boson pairs production processes. By comparing data and simulations we determine the kinematic cuts necessary to isolate the events from the studied process. Several backgrounds cannot be overlooked, namely the W+jets, WZ and Z+jets backgrounds. After highlighting the fact that our simulations failed to estimate properly the W+jets background and that a slight gap between data and simulations is therefore induced, we also undertake a more detailed analysis of the Z+jets by developing a method allowing us to measure the probability of leptons charge misidentication in our data, which we compare to the probability measured in our simulations. On a technical side and althought it did not interfere with our analysis, we noticed a minor failure of the MadGraph software, which we reported to the parties involved.
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institution Organización Europea para la Investigación Nuclear
language fre
publishDate 2017
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spelling oai-inspirehep.net-16322472019-09-30T06:29:59Zhttp://cds.cern.ch/record/2290840freDelannoy, HugoÉtude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMSParticle Physics - ExperimentThis Master's thesis studies the same sign W bosons scattering process and aims to measure its cross section at the LHC using the proton-proton data at 8 TeV in the center of mass in the CMS experiment. This rare process is key in probing the nature of electroweak symmetry breaking and is sensitive to Beyond the Standard Model theories. In September 2013, both the ATLAS and the CMS experiments had yet to go further than preliminary studies with regards to the measurement of the cross section studied in this thesis. We hereby demonstrate that one can isolate the same sign W bosons scattering process from the other W boson pairs production processes. By comparing data and simulations we determine the kinematic cuts necessary to isolate the events from the studied process. Several backgrounds cannot be overlooked, namely the W+jets, WZ and Z+jets backgrounds. After highlighting the fact that our simulations failed to estimate properly the W+jets background and that a slight gap between data and simulations is therefore induced, we also undertake a more detailed analysis of the Z+jets by developing a method allowing us to measure the probability of leptons charge misidentication in our data, which we compare to the probability measured in our simulations. On a technical side and althought it did not interfere with our analysis, we noticed a minor failure of the MadGraph software, which we reported to the parties involved.CERN-THESIS-2014-419oai:inspirehep.net:16322472017-10-28T04:31:41Z
spellingShingle Particle Physics - Experiment
Delannoy, Hugo
Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS
title Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS
title_full Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS
title_fullStr Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS
title_full_unstemmed Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS
title_short Étude de la production de paires de bosons W de même charge au LHC avec les données proton-proton à 8 TeV dans l'expérience CMS
title_sort étude de la production de paires de bosons w de même charge au lhc avec les données proton-proton à 8 tev dans l'expérience cms
topic Particle Physics - Experiment
url http://cds.cern.ch/record/2290840
work_keys_str_mv AT delannoyhugo etudedelaproductiondepairesdebosonswdememechargeaulhcaveclesdonneesprotonprotona8tevdanslexperiencecms