Searches for Higgs bosons with hadronically decaying τ-leptons: Using Grid and Cloud computing techniques
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
This thesis describes a measurement of the Standard Model Higgs boson coupling to fermions in decays to two τ-leptons, a search for charged Higgs bosons in decays to a τ-lepton and a neutrino, as well as the reconstruction, identiﬁcation and triggering of hadronically decaying τ-leptons. The data considered are collected by the ATLAS experiment at the Large Hadron Collider.
The reconstruction and identiﬁcation of hadronically decaying τ-leptons in the ATLAS experiment during Run 2 of the Large Hadron Collider are described, and the performance of the τ trigger is measured in events with top–antitop-quark pairs using data from 13 TeV proton–proton collisions, corresponding to an integrated luminosity of 3.2 fb-1, collected in 2015, and 11.5 fb-1, collected in 2016.
Hadronically decaying τ-leptons are of importance to many physical processes involving Higgs bosons. The coupling of the Standard Model Higgs boson to fermions is measured in decays to two τ-leptons using 7 TeV data corresponding to an integrated luminosity of 4.5 fb-1, collected in 2011, and 8 TeV data corresponding to an integrated luminosity of 20.3 fb-1, collected in 2012. The signal strength is measured to be μ = 1.4, corresponding to an excess over the background-only model of 4.5σ.
Charged Higgs bosons are searched for in decays to a τ-lepton and a neutrino, where the τ-lepton decays hadronically. 13 TeV data corresponding to an integrated luminosity of 14.7 fb-1, collected in 2015 and 2016, are used. No excess over the Standard Model background is observed, and the 95 % conﬁdence-level exclusion limits on σ(pp → [b]tH+) × (H+ → τν) are set to 2.0 pb–8 fb in the range 200–2000 GeV.
Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. , 111 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1434
LHC, ATLAS, Higgs, Charged Higgs, Tau lepton, 2HDM, MSSM
Research subject Physics with specialization in Elementary Particle Physics
IdentifiersURN: urn:nbn:se:uu:diva-304291ISBN: 978-91-554-9706-4OAI: oai:DiVA.org:uu-304291DiVA: diva2:1015018
2016-11-21, Polhemsalen, 10134, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:00 (English)
Eerola, Paula, Professor
Ferrari, Arnaud, Universitetslektor
List of papers