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Phenomenology in multi-scalar extensions of the Standard Model

Ordell, Astrid LU (2020)
Abstract
This thesis is composed of four papers, which all treat various extensions to the Standard Model (SM). The first two papers concern a particular supersymmetric, grand-unified theory (GUT), while in the latter two, we classify anomaly-free implementations of two-Higgs doublet models (2HDM) with a gauged abelian symmetry.

Paper I. In this paper, we present an alternative solution for avoiding GUT-scale lepton masses in so-called trinification based GUT-models (T-GUTs). Rather than introducing several copies of the tri-triplets, which is the conventional approach, we solve the issue by embedding the symmetries into an E8 group.

Paper II. This paper involves a more detailed study of the model proposed in Paper I. Some of... (More)
This thesis is composed of four papers, which all treat various extensions to the Standard Model (SM). The first two papers concern a particular supersymmetric, grand-unified theory (GUT), while in the latter two, we classify anomaly-free implementations of two-Higgs doublet models (2HDM) with a gauged abelian symmetry.

Paper I. In this paper, we present an alternative solution for avoiding GUT-scale lepton masses in so-called trinification based GUT-models (T-GUTs). Rather than introducing several copies of the tri-triplets, which is the conventional approach, we solve the issue by embedding the symmetries into an E8 group.

Paper II. This paper involves a more detailed study of the model proposed in Paper I. Some of its features is an absence of the mu-problem and a universal Yukawa coupling for all chiral fermions.

Paper III. Here, we classify all anomaly-free implementations of a 2HDM with a gauged Abelian symmetry and the SM fermion content. The resulting 11 models are then compared under a range of experimental bounds, from which we identify the most promising ones.

Paper IV. In this paper, we again classify and compare all anomaly-free implementations of a 2HDM with a gauged Abelian symmetry, but this time around also including two generations of right-handed neutrinos. The right-handed neutrinos are incorporated to provide a mechanism for the neutrinos to obtain a mass, here via a type-I seesaw mechanism. In total, there are 16 valid models, which are all compared, both for normal- and inverted ordering. Two models are identified as the most promising candidates for future studies. (Less)
Abstract (Swedish)
Denna sammanläggningsavhandling består av fyra artiklar, som alla berör olika utvidgningar av Standardmodellen (SM). De första två artiklarna behandlar en specifik, supersymmetrisk, storförenad teori (GUT), medan de senare två klassificerar alla anomali-fria instanser av 2-Higgs-dubblett modeller (2HDMs) med en gauge:ad abelsk symmetri.

Artikel I. I denna artikel presenterar vi en alternativ lösning för att undvika lepton massor jämförbara med GUT-skalan, i så kallade trinifikations-baserade GUT modeller (T-GUTs). Istället för att introducera ytterligare kopior av tri-tripletterna, vilket är den konventionella metoden, löses problemet genom att baka in symmetrierna i en E8 grupp.

Artikel II. Denna artikeln involverar en... (More)
Denna sammanläggningsavhandling består av fyra artiklar, som alla berör olika utvidgningar av Standardmodellen (SM). De första två artiklarna behandlar en specifik, supersymmetrisk, storförenad teori (GUT), medan de senare två klassificerar alla anomali-fria instanser av 2-Higgs-dubblett modeller (2HDMs) med en gauge:ad abelsk symmetri.

Artikel I. I denna artikel presenterar vi en alternativ lösning för att undvika lepton massor jämförbara med GUT-skalan, i så kallade trinifikations-baserade GUT modeller (T-GUTs). Istället för att introducera ytterligare kopior av tri-tripletterna, vilket är den konventionella metoden, löses problemet genom att baka in symmetrierna i en E8 grupp.

Artikel II. Denna artikeln involverar en mer detaljerad studie av modellen föreslagen i Artikel I. Till dess framstående drag tillhör frånvaro av my-problemet och en universell Yukawa-koppling för alla kirala fermioner.

Artikel III. Här klassificerar vi alla anomali-fria instanser av en 2HDM med en gauge:ad abelsk symmetri och fermion-innehållet hos SM. De resulterande 11 modellerna är sedan jämförda mot en rad av experimentella restriktioner, från vilka vi identifierar de mest lovande instanserna.

Artikel IV. I denna artikel klassificerar vi igen alla anomali-fria instanser av en 2HDM med en gauge:ad abelsk symmetri, men denna gång inkluderas även två generationer av högerhänta neutriner. De högerhänta neutrinerna är inkorporerade för att introducera en mekanism för att ge massor till de vänsterhänta neutriner vi ser på låga energier, här via en typ-I gungbrädemekanisk. Totalt finns det 16 giltiga modeller, som alla jämförs, både för normal- och inverterad ordning. Två modeller identifieras som de mest lovande kandidaterna för vidare studier. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Dr. Miller, David, University of Glasgow
organization
publishing date
type
Thesis
publication status
published
subject
keywords
BSM, 2HDMs, BSM, 2HDMs, Fysicumarkivet A:2020:Ordell
publisher
Lund University
defense location
Lundmarksalen, Sölvegatan 27, Lund. Join via zoom: https://lu-se.zoom.us/j/66788720581?pwd=eHhYTWZIWHdYWWkwdUcwbk9LL0YzZz09 Lösenord: 497457
defense date
2020-09-18 10:00:00
ISBN
978-91-7895-571-8
978-91-7895-570-1
language
English
LU publication?
yes
id
5f784616-fe31-4360-9478-b9ad922afb53
date added to LUP
2020-08-20 16:08:47
date last changed
2021-06-18 14:58:16
@phdthesis{5f784616-fe31-4360-9478-b9ad922afb53,
  abstract     = {{This thesis is composed of four papers, which all treat various extensions to the Standard Model (SM). The first two papers concern a particular supersymmetric, grand-unified theory (GUT), while in the latter two, we classify anomaly-free implementations of two-Higgs doublet models (2HDM) with a gauged abelian symmetry.     <br/><br/>Paper I. In this paper, we present an alternative solution for avoiding GUT-scale lepton masses in so-called trinification based GUT-models (T-GUTs). Rather than introducing several copies of the tri-triplets, which is the conventional approach, we solve the issue by embedding the symmetries into an E8 group.<br/><br/>Paper II. This paper involves a more detailed study of the model proposed in Paper I. Some of its features is an absence of the mu-problem and a universal Yukawa coupling for all chiral fermions. <br/><br/>Paper III. Here, we classify all anomaly-free implementations of a 2HDM with a gauged Abelian symmetry and the SM fermion content. The resulting 11 models are then compared under a range of experimental bounds, from which we identify the most promising ones. <br/><br/>Paper IV. In this paper, we again classify and compare all anomaly-free implementations of a 2HDM with a gauged Abelian symmetry, but this time around also including two generations of right-handed neutrinos. The right-handed neutrinos are incorporated to provide a mechanism for the neutrinos to obtain a mass, here via a type-I seesaw mechanism. In total, there are 16 valid models, which are all compared, both for normal- and inverted ordering. Two models are identified as the most promising candidates for future studies.}},
  author       = {{Ordell, Astrid}},
  isbn         = {{978-91-7895-571-8}},
  keywords     = {{BSM, 2HDMs; BSM, 2HDMs; Fysicumarkivet A:2020:Ordell}},
  language     = {{eng}},
  publisher    = {{Lund University}},
  school       = {{Lund University}},
  title        = {{Phenomenology in multi-scalar extensions of the Standard Model}},
  url          = {{https://lup.lub.lu.se/search/files/83131554/Astrid_Ordell_WEBB.pdf}},
  year         = {{2020}},
}