Yeh, Yoran;
(2024)
Detector-corrected measurements of missing transverse energy with the ATLAS detector and constraints on new physics models using Contur.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
This thesis first presents differential cross-section measurements of events with large missing transverse energy in association with jets, using 140 fb−1 of data from √s = 13 TeV proton- proton collisions delivered by the Large Hadron Collider (LHC) and measured with the ATLAS detector from 2015 to 2018. Auxiliary measurements with leptons or photons are made in the same kinematic regions, where correlated theoretical and experimental uncertainties cancel in ratios between cross-sections. This analysis is designed to be maximally model-independent and re-interpretable in the context of a wide range of theoretical predictions: the phase space is defined only in terms of the final state particles and results are corrected for detector effects with an iterative Bayesian method. Experimental data are compared to state-of-the-art Standard Model predictions in a likelihood fit that shows adequate modelling of most observables except the invariant dijet mass. The measured cross-sections are also compared to theories beyond the Standard Model. Constraints on a benchmark dark matter model show competitive limits to a dedicated beyond the Standard Model search using the same dataset, proving the effectiveness of using precision measurements in re-interpretation studies. Secondly, improvements are made to several open-source software tools that are at the heart of the LHC re-interpretation ecosystem: RIVET, YODA and CONTUR. The latter is used to set the first collider limits from precision measure- ments on a beyond the Standard Model scenario, in which a particle dark matter candidate arises naturally from gauge anomaly cancellation. Large parts of parameter space are constrained by the presented ATLAS measurement of missing transverse energy. Collider constraints are com- bined with results from cosmology and direct dark matter searches, while sensitivity studies for the future High-Luminosity LHC project show promising prospects to either discover or rule out this model in the near future.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Detector-corrected measurements of missing transverse energy with the ATLAS detector and constraints on new physics models using Contur |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2024. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10200896 |
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