Sökning: "invariant mass"

Visar resultat 1 - 5 av 27 uppsatser innehållade orden invariant mass.

  1. 1. Exploring electroweak symmetry breaking in the scale-invariant Two-Higgs-Doublet Model

    Master-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Författare :Erik Rustas; [2023]
    Nyckelord :Two-Higgs-Doublet Models; 2HDM; Scale-invariance; Baryogenesis; BSM; Baryon Asymmetry; Coleman-Weinberg Potential; Theoretical Particle Physics; Physics and Astronomy;

    Sammanfattning : This thesis investigates the properties of a general scale-invariant Two-Higgs-Doublet Model and its phenomenological consequences with focus on the scalar sector. The concept suggests that introducing more CP-violation, both spontaneous and explicit, may make it possible to meet the Sakharov conditions and account for the Universe's baryon asymmetry. LÄS MER

  3. 2. Constraining the Higgs width in Higgs production associated with a top quark pair

    Kandidat-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Författare :Benjamin Dahlén; [2023]
    Nyckelord :Higgs; width; cross section; on-shell; off-shell; invariant mass; Standard model; upper bound; Physics and Astronomy;

    Sammanfattning : In this thesis we study the width of the Higgs boson in the process pp → t ̄t 4l at LO using MadGraph5_aMC@NLO to generate the events. The contributions including the Higgs signal, continuum background and interference were considered in order to calculate the expected number of events in a broad range of four-lepton invariant masses. LÄS MER

  4. 3. Event categorisation and Machine-learning Techniques in Searches for Higgs Boson Pairs in the ATLAS Experiment at the LHC

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Högenergifysik

    Författare :Milads Emadi; [2023]
    Nyckelord :Particle Physics; ATLAS; BDT; Boosted Decision Tree; Decision Tree; Optimization; Machine Learning; Analysis;

    Sammanfattning : This thesis investigates the pair production of Higgs bosons (di-Higgs events) at the ATLAS experiment in the Large Hadron Collider (LHC), focusing on the channel where one Higgs boson decays into two bottom quarks and the other decays into two tau leptons. The main objective was to determine whether introducing a split in the invariant mass of the decay products from the two Higgs bosons (the di-Higgs mass) and using this as an analysis variable improves the sensitivity of the Boosted Decision Tree (BDT) machine learning algorithm to the di-Higgs signal. LÄS MER

  5. 4. Non-Diffractive Nuclear Excitations In Angantyr

    Master-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Författare :Carl Rosenkvist; [2023]
    Nyckelord :Heavy-ion; non-diffractive; nuclear excitation; secondary interactions; Physics and Astronomy;

    Sammanfattning : To better understand collectivity in high energy physics, the heavy-ion collision model Angantyr was developed to be included in the event generator Pythia. In this model, proton-proton collision phenomenology is extrapolated to heavy-ion collisions without assuming a thermal plasma for particle production. LÄS MER

  7. 5. A study of Spontenous CP Violation in the Scale Invariant 2HDM

    Kandidat-uppsats, Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

    Författare :Jimmy Gunnarsson; [2022]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : In this thesis, we study the Higgs mass spectrum and spontaneous CP violation, where one of the Higgs vacuum expectation values acquires a non-trivial phase θ in a Type-I 2HDM. We begin by investigating CP violating effects at tree-level, and then expand our studies by taking into account one-loop radiative corrections. LÄS MER