Bernius, C.;
(2010)
Investigation of the discovery potential
of a Higgs boson in the t\bar{t}H^{o}, H^{o} \rightarrow b\bar{b} channel with the ATLAS experiment.
Doctoral thesis , UCL (University College London).
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Abstract
The production of a light Standard Model Higgs boson in association with a top-quark pair at the Large Hadron Collider (LHC) is studied in a simulation of the multipurpose ATLAS experiment. The Higgs boson is assumed to decay into a b\bar{b} pair, and the top-quark pair to decay semi-leptonically. The main background process for this channel is the production of t\bar{t} events, which can be divided into reducible and irreducible components. In the process of generating these components separately, an overlap of events is created through the addition of b-quarks to t\bar{t} events via parton showering in the t\bar{t}X sample. These events are already included in the matrix-element cross-section calculation for the t\bar{t}b\bar{b} sample. A new procedure for the overlap removal is presented in this thesis. Two analyses are studied, where one aims at the full reconstruction of the nal state using a cut-based approach. Recently, this way of reconstructing the t\bar{t}H^{o}(H^{o}\rightarrow b\bar{b}) process has been found to be extremely challenging. The other analysis is based on a new method employing state-of-the-art jet reconstruction and decomposition techniques where the t\bar{t} pair and the Higgs boson are required to have large transverse momenta and can therefore be reconstructed as massive Higgs and top jets. A recent phenomenological study has shown that the t\bar{t}H^{o} process can be recovered as a promising search channel for a low mass Standard Model Higgs boson around 120 GeV using this approach. Finally, to enhance the sensitivity of the t\bar{t}H^{o} channel, a combination of the two analyses is presented.
Type: | Thesis (Doctoral) |
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Title: | Investigation of the discovery potential of a Higgs boson in the t\bar{t}H^{o}, H^{o} \rightarrow b\bar{b} channel with the ATLAS experiment |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | The title and abstract contain LaTeX text. Please see the attached pdf for rendered equations |
UCL classification: | 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/757393 |
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