This thesis outlines the search for neutral Higgs bosons in a mass range of m<sub>H/A</sub> = 200 GeV â 1.2 TeV, decaying to a pair of hadronically decaying tau leptons. The search is performed using √s = 13 TeV proton-proton collision data, corresponding to an integrated luminosity of 3.21 fb<sup>-1</sup>, recorded by the ATLAS detector. No excess over the predicted Standard Model background is observed and upper limits are placed on the production cross section times branching fraction as a function of the mass of the scalar resonance. When combined with the results of the analysis where one of the tau leptons decays to either a muon or electron, the 95% confidence level upper limit on the cross section times branching fraction ranges from 1.4 pb at m<sub>H/A</sub> = 200 GeV to 0.025 pb at m<sub>H/A</sub> = 1.2 TeV for a scalar boson produced via gluon-gluon fusion, and 1.6 pb at m<sub>H/A</sub> = 200 GeV to 0.028 pb at m<sub>H/A</sub> = 1.2 TeV for a scalar boson produced via b-associated production. The results are interpreted in the Minimal Supersymmetric extension to the Standard Model (MSSM) as a limit on the value of tanβ, as a function of the mass of the neutral CP-odd MSSM Higgs boson. In the mmod+ scenario, the 95% confidence level upper limit is tanβ < 7.6 for m<sub>A</sub> = 200 GeV, and tanβ < 47 for m<sub>A</sub> = 1 TeV. For the mass range m<sub>A</sub> > 500 GeV, the upper limit on tanβ is improved in comparison to previous ATLAS searches.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:730439 |
| Date | January 2016 |
| Creators | Pickering, Mark Andrew |
| Contributors | Hays, Chris |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:1d996f69-4aaa-421b-bf72-88ef5a0fbffc |
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