Essays about: "leptons"

Showing result 1 - 5 of 28 essays containing the word leptons.

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

    University essay from Uppsala universitet/Högenergifysik

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

    Abstract : 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. READ MORE

  3. 2. Determining backgrounds with misidentified leptons in the ATLAS Higgs boson analysis

    University essay from KTH/Fysik

    Author : Leo Qiyuan Hu; [2023]
    Keywords : Particle Physics; ATLAS detector; Fake Factor method; Higgs boson; lepton misreconstruction; misidentified events; Partikelfysik; ATLAS detektorn; Fake Factor-metoden; Higgs boson; lepton felrekonstruktion; felidentifierade händelser;

    Abstract : This thesis presents an analysis of misidentified leptons in the Higgs boson decaychannel H → W W ∗ → lνlν. Misidentified leptons, resulting from jets misidentifiedas leptons, mimic the signal of a Higgs boson decay, resulting in a backgroundcontribution to the signal. READ MORE

  4. 3. Signatures of Dark Matter at the LHC : A phenomenological study combining collider and cosmological bounds to constrain a vector dark matter particle model

    University essay from Uppsala universitet/Högenergifysik

    Author : Anton Olsson; [2022]
    Keywords : Dark matter; particle phenomenology; LHC; MadGraph; standard model; beyond standard model;

    Abstract : Everything that humans have ever touched, created or built something from consists of a type of matter that only makes up 15 percent of the total matter in the universe. The remaining 85 percent is attributed to dark matter, a so far not discovered and non-luminous type of matter. READ MORE

  5. 4. Spin correlations in top quark pair production at the Large Hadron Collider

    University essay from Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Author : Simon Ahlstedt; [2022]
    Keywords : Top quarks; Top quark pair production; LHC; Spin correlations; MadGraph5_aMC@NLO; Dilepton decay channel; Leading order; Interference effects; Event generation.; Physics and Astronomy;

    Abstract : In this work we investigate the spin correlation effect of the interference between signal and irreducible background events present in top quark pair production at the LHC at LO in the dilepton channel. To simulate the high energy proton-proton collisions of the LHC, MadGraph5_aMC@NLO framework is used as an event generator. READ MORE

  6. 5. Study of the doubly charged Higgs boson single production using lepton parton distribution functions with the ATLAS detector

    University essay from Lunds universitet/Partikel- och kärnfysik; Lunds universitet/Fysiska institutionen

    Author : Daniel Magdalinski; [2022]
    Keywords : doubly charged Higgs boson; ATLAS; lepton parton distribution function; same-sign; dilepton; beyond standard model; LHC; Physics and Astronomy;

    Abstract : Searches for the doubly charged Higgs(H±±) aim to find evidence for models that could explain the origin of neutrino masses. Earlier searches at the LHC have used different production processes for the H±±, with the recent development of lepton parton distribution functions new leptonic production processes are able to be studied. READ MORE