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Author ORCID Identifier

https://orcid.org/0000-0001-6169-0517

AccessType

Campus-Only Access for Five (5) Years

Document Type

dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Physics

Year Degree Awarded

2022

Month Degree Awarded

September

First Advisor

Rafael Coelho Lopes de Sa

Subject Categories

Elementary Particles and Fields and String Theory

Abstract

A measurement of off-shell Higgs boson production in the ZZ → 4ℓ decay channel, where ℓ stands for either an electron or a muon, is performed using data from proton-proton collisions at a center-of-mass energy of √s = 13TeV. The data was collected by the ATLAS experiment from 2015 to 2018 at the Large Hadron Collider and corresponds to an integrated luminosity of 139 ifb. An observed (expected) upper limit on the off-shell Higgs signal strength, defined as the event yield normalized to the Standard Model prediction, μoff-shell = 0.99+0.63 −0.57 (μoff-shell = 1.08+0.78 −0.91) is obtained. Assuming the ratio of the Higgs boson couplings to the Standard Model predictions are independent of the momentum transfer of the Higgs boson production mechanism considered in the analysis, a combination with the on-shell signal-strength measurements yields an observed (expected) measurement for the Higgs boson total width is ΓH = 3.02+2.40 −1.70 MeV (ΓH = 4.04+2.28 −2.33 MeV)

DOI

https://doi.org/10.7275/31003970

Creative Commons License

Creative Commons Attribution-Share Alike 4.0 License
This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License.

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