Browsing Fakultät für Physik (inkl. GAUSS) by Referee "Lai, Stan Prof. Dr."
Now showing items 1-20 of 23
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Novel Approaches to the Fast Simulation of the ATLAS Calorimeter and Performance Studies of Track-Assisted Reclustered Jets for Searches for Resonant $X \rightarrow SH \rightarrow b\bar{b} WW^*$ Production with the ATLAS Detector
(2023-05-30)One of the most essential tools for all measurements and searches at the LHC experiments is the Monte Carlo (MC) simulation of proton-proton collisions. The generation of MC events, in particular the simulation of the ... -
Higher Order Electroweak and QCD Corrections in e+e−μ+μ− production at LHC
(2022-11-09)This thesis focuses on improving the theoretical modelling of the process pp → e+e−μ+μ− at LHC by including both EW and QCD higher-order perturbative corrections. The EW corrections are studied at NLO fixed order and in ... -
Search for resonant Higgs boson pair production in the bb̄WW* decay channel in the boosted 1-lepton final state using the full Run 2 ATLAS dataset
(2022-05-03)Despite the great success of the Standard Model of Particle Physics in explaining physics phenomena over a wide range of energy scales, many open questions remain and it is known that this model of nature is incomplete. ... -
Measurement of the branching fractions of the semileptonic decays B+ → ηlν and B+ → η′lν with signal-side only reconstruction at the Belle experiment
(2021-11-25)This thesis presents a measurement of the branching fractions of the decays B+ → ηlν and B+ → η'lν. The entire data sample collected by the Belle experiment at the energy of the Υ(4S) resonance is used, which contains ... -
Search for BSM A/H → τ τ in the Fully Hadronic Decay Channel with ATLAS
(2021-11-16)In 2012, a scalar boson was found at CERN that is consistent with the properties of the Higgs boson predicted by the Standard Model (SM) of particle physics. Some theories, in particular supersymmetric models, also predict ... -
Pair production of Higgs bosons in the final state with bottom quarks and τ leptons in the ATLAS experiment: Search results using LHC Run 2 data and prospect studies at the HL-LHC
(2021-03-30)After the discovery of the Higgs boson, the ultimate test of the electroweak symmetry breaking and the Standard Model (SM) of particle physics is to establish evidence of Higgs boson self-coupling, which can be achieved ... -
Investigation of the CP properties of VBF Higgs production in hadronic final states of H → τ τ decays with the ATLAS detector
(2021-02-15)A test of CP invariance of the VBF Higgs production process is presented in the τ τ final state. For this, a profile likelihood fit using a matrix-element observable method is employed to test whether a CP-odd component ... -
Search for the production of four top quarks in proton-proton collisions at $\sqrt{s}=13\,$TeV in the single and opposite sign dilepton channels with the ATLAS detector at the LHC using a Monte Carlo correction method
(2020-10-13)The search for the production of $\text{t}\bar{\text{t}}\text{t}\bar{\text{t}}$ in $pp$ collisions at $\sqrt{s}\,=\,13\,$TeV is presented in this thesis for the full \lhc \runii dataset of 139$\,$fb$^{-1}\,$collected by ... -
Search for the production of four top quarks in proton-proton collisions at $\sqrt{s}=13$ TeV in the single lepton and opposite-sign dilepton channels with the ATLAS detector at the Large Hadron Collider
(2020-07-28)This thesis presents the search for the production of $t\bar{t}t\bar{t}$ from $pp$ collision at $\sqrt{s} = 13$ TeV. The analysed dataset has been collected by the ATLAS detector during the LHC Run 2, corresponding to an ... -
Observation of the Standard Model Higgs boson produced in association with a pair of top quarks at $\sqrt{s} = 13 \, \text{TeV}$ with the ATLAS experiment at the LHC with emphasis on the decay of the Higgs boson into a $b\bar{b}$-pair in the single-lepton channel
(2019-10-30)The top quark is the heaviest elementary particle in the Standard Model and has an expected Yukawa coupling to the Higgs boson of order unity. The value of this coupling is a key ingredient to unravel the nature of the ... -
Measurement of the $W$ Boson Polarisation in $t\bar{t}$ Dilepton Events at $\sqrt{s}=8$ TeV with the ATLAS Detector
(2019-10-18)A measurement of the $W$ boson polarisation in top quark decays is presented. The top anti-top pairs were produced at a centre of mass energy of $\sqrt{s}=8$ \tev \ using proton-proton collisions at the LHC. The data sample ... -
Direct measurement of the top-quark decay width with the ATLAS detector
(2019-07-10)The top quark is the heaviest known elementary particle. Due to its large mass, the top quark decays before it forms bound states. This makes the top quark a unique particle in the Standard Model. Precise measurements of ... -
Measurement of the Higgs boson production in the H → ττ → τlepτhad decay channel at √s = 13 TeV with the ATLAS detector at the LHC
(2019-06-14)This thesis presents a measurement of the Standard Model Higgs boson production in the H → ττ decay with particular emphasis on the final state in which one tau decays hadronically and the other one decays leptonically, ... -
Calibration of the ATLAS B-tagger and the search for the $t\overline{t}H(H\rightarrow b\overline{b})$ process at $\sqrt{s}$ = 13 TeV with the ATLAS experiment at the LHC
(2019-04-24)Top quarks and Higgs bosons are the heaviest particles in the Standard Model of particle physics and are the subject of many analyses performed with the ATLAS experiment at the LHC at CERN. The Higgs boson was discovered ... -
Refining the chemical and kinetic decoupling description of thermally produced dark matter
(2019-03-26)The first part of this thesis deals with refined theoretical predictions of the thermal relic abundance for weakly interacting massive particles (WIMPs). Methods are developed in a model independent way to describe the ... -
Measurement of the Higgs Boson Production Cross Section in Hadronic Final States in 13 TeV Proton-Proton Collisions with the ATLAS Detector
(2019-01-04)The couplings of the Standard Model Higgs boson to fermions provide valuable insights into the nature of electroweak symmetry breaking in the Yukawa sector. This thesis summarises the measurement of the Higgs boson ... -
Fiducial cross-section measurements of the production of a prompt photon in association with a top-quark pair at $\sqrt{s}=13$ TeV with the ATLAS detector at the LHC
(2018-11-23)The cross sections for top-quark pair production in association with a photon are measured in a fiducial volume with the ATLAS detector at a centre-of-mass energy of 13 TeV. Results are presented using proton-proton collision ... -
Measurement of the ttZ Production Cross Section in the Final State with Three Charged Leptons using 36.1 fb^-1 of pp Collisions at 13 TeV at the ATLAS Detector
(2018-02-14)A measurement of the production cross section for a top quark pair in association with a Z boson (ttZ) is presented in this PhD thesis. Final states with exactly three charged leptons (electrons or muons) are used, taking ... -
Direct Top Quark Decay Width Measurement in the tt Lepton+Jets Channel at 8 TeV with the ATLAS Experiment
(2017-11-09)The top quark t plays an essential role in the field of elementary particle physics - in particular due to its exceptional properties comprising a large mass, which approximately equals the mass of a tungsten atom, and an ... -
Search for the Standard Model Higgs boson produced in association with a pair of top quarks and decaying into a bb-pair in the single lepton channel at √s = 13 TeV with the ATLAS experiment at the LHC
(2017-07-05)This thesis presents a search for Standard Model Higgs boson produced in association with top quark pairs, ttH. The analysis uses 13.2 fb-1 of pp collision data at √s = 13 TeV collected in 2015 and 2016 ...