Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"missing transverse momentum"”.
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Analysis of a deep neural network for missing transverse momentum reconstruction in ATLAS
… particles can be inferred by the observed momentum imbalance in the transverse plane. In this work, a deep neural network was trained using supervised learning to measure this imbalance. The performance of this network was evaluated in MC simulation and in 43 fb⁻¹ of data recorded at ATLAS. …
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Analysis of Events with Isolated Leptons and Missing Transverse Momentum in ep Collisions at HERA
A study of events with isolated leptons and missing transverse momentum in ep collisions is presented. Within the Standard Model (SM) such topologies are expected mainly from production of real W bosons with subsequent leptonic decay. This thesis continues the analysis of such events done in the …
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Two leptons, jets, and missing transverse momentum in ATLAS: yet more non-evidence for supersymmetry
Searching for new phenomena is an essential endeavour of experimental physics, and is helped by guidance from plausible theoretical predictions. This thesis presents such a search for signals of high-energy protons scattering to massive resonances with dramatic decays, which are predicted by …
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Building the Future: HL-LHC ATLAS Upgrades and Event-Topology-Based Principles to Search for New Physics with Missing Transverse Momentum
… interaction processes that produce significant missing transverse momentum. The tools are tested on Monte Carlo simulation events prepared for a search for gluino-pair production in $140~\fb$ of proton proton collision at $\sqrt{s}=13~\textrm{TeV}$ with the ATLAS detector. Direct comparison with …
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First search for electroweak supersymmetry in final states with hadronic decays of WW, WZ, or WH boson pair and missing transverse momentum.
… a pair of bosons (WW, WZ, or WH) with large missing transverse momentum arising from the lightest neutralinos (χe 0 1 ). Deep neural network large-radius jet taggers are used to identify hadronic decays of the bosons. The standard model backgrounds are estimated using data-driven techniques. …
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Rare phenomena and W production in electron proton scattering at HERA
… photons, muons, neutrinos and jets with high transverse momenta are investigated. Events are classified into exclusive event classes according to their final state. A new algorithm is used to look for regions with deviations from the Standard Model in the invariant mass and sum of transverse …
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Theoretical and experimental approaches to the dark energy and the cosmological constant problem.
… is based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at $\sqrt{s}=13\TeV$. The data sample, corresponding to an integrated luminosity of 2.3~$\fbinv$, was collected with the CMS detector at the CERN LHC in 2015. The data are examined in …
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A Measurement of the Jet Multiplicity in Di-lepton Final States of ttbar Events
… ttbar events (i.e. ttbar → (ee, μμ, eμ) + missing transverse momentum + jets) is presented, using 4.66 fb -1 of data collected from √ s = 7 TeV pp collisions at the CERN Large Hadron Collider. In order to mitigate the effects of systematic uncertainties associated with jet energy …
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A Search For New Physics Using tt(bar) Resonances in the Lepton Plus Jets Channel at √(s) = 8 TeV in 20 fb⁻¹ of pp Collision Data at the ATLAS Experiment
… is done by requiring one electron or muon, large missing transverse momentum and additional hadronic jets. The tt(bar) system is reconstructed using techniques optimized for either resolved or boosted event topologies. The results of the analysis are used to set upper limits on the production …
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Improved Search for Heavy Neutral Scalars A and H Using ttZ Events from 13 TeV pp Collisions at CMS
… targets events with three charged leptons, missing transverse momentum, and four or more jets, at least one of which is b-tagged. From these, a Z boson candidate and two top quark candidates are reconstructed, allowing reconstruction of the heavy resonances. No evidence for a signal is …
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Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
… precision of the measurement at lower values of transverse momentum. In tandem, a search for new physics in events with a Z boson produced in association with large missing transverse momentum is presented. The results of this search are interpreted in the context of several dark matter models: …
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Enhancing the sensitivity of the ATLAS experiment to electroweak supersymmetry
… to improve the reconstruction performance of missing transverse momentum ($p_T^{miss}$) – an essential variable in many searches for supersymmetry. Two neural-network-based approaches are compared and their potential to enhance the sensitivity of ATLAS to pMSSM scenarios is evaluated.
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Observation of the electroweak production of two same-sign W bosons in proton-proton collisions with the ATLAS detector
… same sign leptons (e±e±, e± µ± and µ±µ± ), large missing transverse momentum (Emiss T ) and two forward jets using 36.1 fb1 of data collected at a proton-proton center of mass energy of 13 TeV in 2015 and 2016. This thesis presents an overview of the observation of this rare process by the ATLAS …
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Electroweak symmetry breaking in the era of the Higgs boson discovery
… such as jet multiplicity, summed scalar transverse momentum, and missing transverse momentum can be recovered within this approach. We show that in this framework trimming can be recast as a particle weight assignment, without explicit jet identification. Finally, we comment on potential …
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TRACKING THE INVISIBLE. A SEARCH FOR SUPERSYMMETRIC HIGGSINOS WITH THE ATLAS DETECTOR.
… are relatively long-lived and decay into low-momentum charged pions, which are reconstructed as soft tracks displaced by a few millimeters from the proton-proton interaction point and characterised by unusually large impact parameters. The resulting final-state signature is defined by the …
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Holly Pacey and the Half-Spin Particles: Searching for new physics with leptons at the ATLAS experiment
… in two regions of phase space (one with missing transverse momentum and one with a hard jet in the final state, respectively), as well as providing measurements binned in different variables. Furthermore, the search places the first direct exclusion limits at the LHC for single-production …
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Extending the Reach of Searches for Staus, Charginos and Neutralinos with the ATLAS Experiment at the Large Hadron Collider
… in a final state with an energetic jet and large missing transverse momentum is compared to a sensitivity study of a vector boson fusion channel. The re-interpretation is found to have sensitivity to previously uncovered regions of parameter space; for a simplified wino/bino interpretation models …