Department of Physics
Library of the School of Science

2021-11-19

2021

Koraka Charis-Kleio

Νίκη Σαουλίδου (Κύρια Επιβλέπουσα) Αναπληρώτρια Καθηγήτρια, Τμήμα Φυσικής, ΕΚΠΑ

Δημήτριος Φασσουλιώτης Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ

Γεώργιος Αναγνώστου, ΕΡΕΥΝΗΤΗΣ Β ́- Ινστιτούτου Πυρηνικής και Σωματιδιακής Φυσικής (ΙΠΣΦ) Εθνικό Κέντρο Έρευνας Φυσικών Επιστημών «Δημόκριτος» (ΕΚΕΦΕ)

Κωσταντίνος Βελλίδης , Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ

Κωσταντίνος Κόρδας, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης

Αθανάσιος Δέδες, Καθηγητής, Τμήμα Φυσικής Πανεπιστήμιο Ιωαννίνων

Dr. Matthias Schroeder, Staff Scientist στο Ινστιτούτο Πειραματικής Φυσικής του Πανεπιστημίου του Αμβούργου της Γερμανίας

Study of the Higgs boson in association with two top quarks and its subsequent decay to a bb pair with the CMS detector at the LHC, at CERN

English

Study of the Higgs boson in association with two top quarks and its subsequent decay to a bb pair with the CMS detector at the LHC, at CERN

In this thesis, a novel approach for the measurement of the associated production of a
Higgs boson with a top quark-antiquark pair in the dileptonic channel, where the Higgs
boson decays hadronically to a b quark-antiquark pair (tt̄H, H → bb̄), is presented. A new
method is introduced, which achieves the kinematic reconstruction of the Higgs invariant
mass from its decay products. The mass reconstruction is performed by analytically
solving the tt̄H dileptonic decay system of equations while scanning the m top and m W
mass plane searching for solutions. The analysis uses dilepton events in the ee, μμ and
eμ channels. The events are separated into a signal and a control region, based on
the number of b-tagged jets of each event. The main background contribution, which
comes from tt̄ events, is predicted in a data-driven manner making use of the Tag Rate
Function method. The measurement is performed utilizing L = 137.2 fb −1 of pp collision
data recorded at a center-of-mass energy of s = 13 TeV by the CMS experiment at the
CERN LHC. The resulting observed (expected) significance corresponds to 0.34 (1.35)
standard deviations.

Science

Higgs Boson, Paricle Physics, top quark, CERN, CMS LHC

Yes

29

Yes

107

320

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https://pergamos.lib.uoa.gr/uoa/dl/object/2966128