doctoral thesis
Jakob Novak (Author), Borut Paul Kerševan (Mentor), Andrej Gorišek (Co-mentor)

Abstract

The thesis presents the search for Higgs boson pair production where one Higgs boson decays via $H\to bb$ and the other Higgs boson decays via $H/S \to WW^* \to \ell\nu qq$ (where $\ell$ is either an electron or a muon). The latter can be Standard Model Higgs boson or beyond Standard Model Higgs boson with same couplings but different mass. Analysed data consists of pp collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. Full Run 2 dataset corresponding to integrated luminosity of 140.1 fb$^{-1}$ is used. Machine learning approach is adopted for selection of events matching the signal topology. No statistically significant evidence of a signal is observed and corresponding upper limits on the production cross-section for $HH$ and $SH$ production are derived.

Keywords

physics of elementary particles;Higgs bosons;machine learning;ATLAS detector;

Data

Language: English
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UL FMF - Faculty of Mathematics and Physics
Publisher: [J. Novak]
UDC: 539.129.4
COBISS: 189458947 Link will open in a new window
Views: 65
Downloads: 6
Average score: 0 (0 votes)
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Other data

Secondary language: Slovenian
Secondary title: Iskanje procesov s parom Higgsovih bozonov z detektorjem ATLAS na trkalniku LHC
Secondary abstract: V doktorskem delu sem predstavil iskanje procesov s parom Higgsovih bozonov, v katerih en Higgsov bozon razpade preko $H\to bb$ in drugi Higgsov bozon prek $H/S \to WW^* \to \ell\nu qq$ (kjer je $\ell$ bodisi elektron ali mion). Slednji je lahko Higgsov bozon Standardnega modela ali Higgsov bozon izven Standardnega modela, z enakimi sklopitvami, vendar drugačno maso. Ta analiza vključuje celotno statistiko drugega obdobja (Run 2) zajemanja podatkov z detektorjem ATLAS na trkalniku LHC. Integrirana luminoznost znaša 140,1 fb$^{-1}$ pri težiščni energiji 13 TeV. Za izbiro dogodkov, ki ustrezajo topologiji signala, je uporabljena metoda strojnega učenja. Opaženih ni nobenih statistično signifikantnih odstopanj od napovedi ozadja. Izračunane so izključitvene meje na sipalni presek za produkcijo $HH$ in $SH$ signala.
Secondary keywords: fizika osnovnih delcev;Higgsovi bozoni;strojno učenje;detektor ATLAS;
Type (COBISS): Doctoral dissertation
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za matematiko in fiziko, Oddelek za fiziko
Pages: XX, 231 str.
ID: 23575256