Citation Link: https://doi.org/10.25819/ubsi/10988
Towards a simultaneous measurement of the top-quark mass and decay width with 13 TeV ATLAS data using bb4l Monte-Carlo predictions
Alternate Title
Auf dem Weg zu einer simultanen Messung der Top-Quark Masse und der Zerfallsbreite mit 13 TeV ATLAS-Daten unter Verwendung von bb4l Monte-Carlo Vorhersagen
Publication Type
Doctoral Thesis
Author(s)
Date Issued
2026
Abstract
This thesis presents a sensitivity study for a simultaneous measurement of two parameters of the heaviest known elementary particle: the top-quark mass and its decay width. The analysis is based on the full Run 2 dataset, corresponding to an integrated luminosity of 140/fb of proton-proton collisions at a centre-of-mass energy of 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. The study focuses on the WWbb production process in the dilepton decay channel and exploits the sensitivity of the invariant mass distribution of a charged lepton and a b-jet to both the top-quark mass and decay width. This sensitivity can be only reliably described using next-to-leading-order predictions for the full WWbb final state in the dilepton channel. A central aspect of this work is the validation of a corresponding Monte-Carlo simulation within the ATLAS Collaboration, including a comprehensive evaluation of the associated modelling uncertainties. This simulation constitutes a valuable input not only for the measurement presented here, but also for future ATLAS analyses targeting the WWbb final state. In the context of this measurement, the use of these improved predictions is shown to significantly enhance the sensitivity to the top-quark decay width, reducing the expected uncertainty by approximately a factor of two compared to the currently most precise measurement.
License
Creative Commons license
File(s)![Thumbnail Image]()
Loading...
Name
Dissertation_Voss_Katharina.pdf
Size
39.5 MB
Format
Adobe PDF
Checksum
(MD5):2740118ac4060ef1f0d8433ec469a4b8
Owning collection
Mapped collections