Please use this identifier to cite or link to this item:
Title: Feasibility study for inclusive measurements of Higgs branching ratios to hadronic final states with the ATLAS detector
Authors: Angelopoulou, Athanasia - Konstantina
Γαζής Ευάγγελος
Keywords: Higgs boson
Flavour tagging
Hadronic decays
Branching ratios
Inclusive measurement
QCD background
MV2c10 algorithm
Issue Date: 29-May-2020
Abstract: The investigation of the decay properties of the Higgs boson is an important part of the LHC physics programme. An accurate determination of the decay branching ratios to the hadronic states bb, cc, gg is necessary for studying the Higgs couplings and thus clarifying the understanding of the particle mass generation mechanism and validating the predictions of the Standard Model. At the same time, possible deviations from these values could indicate the existence of new physics. Identifying hadronic states is based on flavour tagging jets and as current methods are able to mostly identify well b-jets, the branching ratio of the Higgs boson to charm quarks has not been measured. This work studies the feasibility of doing an inclusive measurement of the Higgs hadronic branching ratios. The attempt at determining all three of them simultaneously is based on di-jet discriminants created using the response of a flavour tagging algorithm. For this to be possible, it's necessary to first extract the contribution from background processes attributed to the strong interaction. Thus, the flavour composition of the background is studied and a methodology for estimating it in the signal region is developed. This thesis shows that with the present flavour tagging accuracy, the branching ratios cannot be determined. Therefore, modifications to the output of the flavour tagging algorithm are examined. The study demonstrates the required level of efficiency and mistagging rate of flavour tagging for enabling the analysis with the goal to motivate further enhancements in the discrimination between b-, c- and light-flavour jets.
Appears in Collections:Διπλωματικές Εργασίες - Theses

Files in This Item:
File Description SizeFormat 
dipl_thesis.pdf4.91 MBAdobe PDFView/Open

Items in Artemis are protected by copyright, with all rights reserved, unless otherwise indicated.