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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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Lenguaje: | fre |
Publicado: |
2017
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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. |
id | oai-inspirehep.net-1632247 |
institution | Organización Europea para la Investigación Nuclear |
language | fre |
publishDate | 2017 |
record_format | invenio |
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 |