Zhang, Yuwen;
(2025)
The Search for di-Higgs Production in the 4b Final State with the ATLAS Detector.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Zhang_10204430_thesis.pdf Download (20MB) | Preview |
Abstract
This thesis focuses on the search of non-resonant Higgs boson pair production in the 4b final state at the LHC with the Atlas detector. The main published result uses 126fb of pp collision data to centre of mass energy of 12 TeV, targeting both the gluon-gluon fusion(GAF) and vector-boson fusion(VBF) production modes. No evidence of HH production is observed with the observed (expected) upper limit on the cross-section being 5.4 (8.1) times the Standard Model prediction at 95% confidence level. The observed(expected) constraint on the HHH coupling modifier k2V are [-0.03,2.11]([-0.05,2.12]), also at 95% confidence level. An extension study of training a classifier on background modelling output as discriminant is also discussed. Several technical works about triggers are also presented: improving track finding efficiency for b-jet signature for Inner Detector Triggers; and investigation of triggers to be used in Run 3 analysis. In addition to the ATLAS analysis, I also worked on a simulation study for the Circular Electron Positron Collider(CEPC). The study simulates the search for exotic decays of the Higgs boson into a pair of spin-zero particles considering the scenario of analysing 5000fb e+e- collision data at centre of mass energy of 240 GeV from CEPC, with the conclusion that the sensitivity can be significantly larger than that can be achieved at LHC.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | The Search for di-Higgs Production in the 4b Final State with the ATLAS Detector |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2025. 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/10204430 |
Loading...
Loading...Loading...Loading...Archive Staff Only
 |
View Item |
