Cargando…

A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector

The Standard Model of particle physics is a very successful theory, but it cannot describe e.g. gravity or explain the hierarchy problem. Supersymmetry is a proposed extension to the Standard Model that would solve some of its shortcomings by introducing a relation between fermions and bosons throu...

Descripción completa

Detalles Bibliográficos
Autor principal: Schneider, Basil
Lenguaje:eng
Publicado: 2014
Materias:
Acceso en línea:http://cds.cern.ch/record/1709233
_version_ 1780936631634624512
author Schneider, Basil
author_facet Schneider, Basil
author_sort Schneider, Basil
collection CERN
description The Standard Model of particle physics is a very successful theory, but it cannot describe e.g. gravity or explain the hierarchy problem. Supersymmetry is a proposed extension to the Standard Model that would solve some of its shortcomings by introducing a relation between fermions and bosons through the existence of a supersymmetric partner to every particle in the Standard Model. Since it is a broken symmetry, supersymmetric particles are heavier than their Standard Model counterparts. No supersymmetric particle has been observed to date. The ATLAS experiment at the Large Hadron Collider is a multi-purpose detector to measure parameters in the Standard Model and conduct searches for new particles. Searching for supersymmetric particles is one of the main goals of the experiment. In 2012, 20.3~fb$^{-1}$ of data at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV was collected by ATLAS. In this thesis, I analyzed the ATLAS data and developed a novel statistical approach that bins a signal enhanced region in phase space into many sub-regions. In a later step, these regions are statistically combined to enhance the sensitivity to a supersymmetric signal. The use of modern likelihood techniques allows to apply my method in a consistent and general way to supersymmetry searches. It can also be applied to other searches. Since no excess in data is observed, I set limits on masses of the supersymmetric particles. The results are compared with another search, which interpreted its results in the same models. My method led to an observed improvement of the limit on the supersymmetric particle masses at the 95 % confidence level of up to 100 GeV, only by only improving the search method, without the need of additional data. I also tested optical receiver components which are built into the readout chain of a new detector subsystem. The tests carried out are also explained in this thesis.
id cern-1709233
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2014
record_format invenio
spelling cern-17092332019-09-30T06:29:59Zhttp://cds.cern.ch/record/1709233engSchneider, BasilA general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detectorParticle Physics - ExperimentThe Standard Model of particle physics is a very successful theory, but it cannot describe e.g. gravity or explain the hierarchy problem. Supersymmetry is a proposed extension to the Standard Model that would solve some of its shortcomings by introducing a relation between fermions and bosons through the existence of a supersymmetric partner to every particle in the Standard Model. Since it is a broken symmetry, supersymmetric particles are heavier than their Standard Model counterparts. No supersymmetric particle has been observed to date. The ATLAS experiment at the Large Hadron Collider is a multi-purpose detector to measure parameters in the Standard Model and conduct searches for new particles. Searching for supersymmetric particles is one of the main goals of the experiment. In 2012, 20.3~fb$^{-1}$ of data at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV was collected by ATLAS. In this thesis, I analyzed the ATLAS data and developed a novel statistical approach that bins a signal enhanced region in phase space into many sub-regions. In a later step, these regions are statistically combined to enhance the sensitivity to a supersymmetric signal. The use of modern likelihood techniques allows to apply my method in a consistent and general way to supersymmetry searches. It can also be applied to other searches. Since no excess in data is observed, I set limits on masses of the supersymmetric particles. The results are compared with another search, which interpreted its results in the same models. My method led to an observed improvement of the limit on the supersymmetric particle masses at the 95 % confidence level of up to 100 GeV, only by only improving the search method, without the need of additional data. I also tested optical receiver components which are built into the readout chain of a new detector subsystem. The tests carried out are also explained in this thesis.CERN-THESIS-2014-056oai:cds.cern.ch:17092332014-06-16T08:14:12Z
spellingShingle Particle Physics - Experiment
Schneider, Basil
A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector
title A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector
title_full A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector
title_fullStr A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector
title_full_unstemmed A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector
title_short A general approach to search for supersymmetry at the LHC by combining signal enhanced kinematic regions using the ATLAS detector
title_sort general approach to search for supersymmetry at the lhc by combining signal enhanced kinematic regions using the atlas detector
topic Particle Physics - Experiment
url http://cds.cern.ch/record/1709233
work_keys_str_mv AT schneiderbasil ageneralapproachtosearchforsupersymmetryatthelhcbycombiningsignalenhancedkinematicregionsusingtheatlasdetector
AT schneiderbasil generalapproachtosearchforsupersymmetryatthelhcbycombiningsignalenhancedkinematicregionsusingtheatlasdetector