Search for Neutral Higgs Bosons of the MSSM decaying to τhad τhad in proton-proton collisions at √s = 8 TeV with the ATLAS detector
Search for Neutral Higgs Bosons of the MSSM decaying to τhad τhad in proton-proton collisions at √s = 8 TeV with the ATLAS detector
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DissertationDate of Exam
15.07.2016Date of Publication
21.11.2016Advisor
Dingfelder, Jochen ChristianCo-Referee
Desch, KlausMetadata
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Abstract
A search for the neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model, h, H and A, is presented in this thesis. It is based on a data sample with an integrated luminosity of Lint = 19:5 fb-1 from proton-proton collisions with a center-of-mass energy of √s = 8 TeV produced at the LHC and recorded by the ATLAS experiment in 2012. The search is performed in the decay channel with two tau leptons decaying hadronically, h/H/A → τhad τhad. The selection of events is based on the kinematic and topological properties of a heavy neutral Higgs boson produced by bb annihilation and the gluon-gluon fusion production mechanisms.
The search significantly improves upon the sensitivity of previous searches, and leads the sensitivity of the h/H/A → ττ combined search, where other tau decay modes are selected in the final state, for signal masses mA >∼ 350 GeV.
As no significant excess is found, exclusion limits are set in the space of the two leading-order free parameters of the MSSM, mA and tanβ. After the discovery of a Higgs boson in 2012, with a mass of mH = 125.09 ± 0.24 GeV, new phenomenological scenarios of the MSSM were proposed. In this search, exclusion limits are obtained for these various scenarios in the mass range mA = 170 - 1000 GeV. Model-independent exclusion limits were also obtained for the cross-section of the production of a generic resonance, φ, by bb annihilation and gluon-gluon fusion. Excluded cross-sections at 95% confidence level are as high as σexcl.(bb→ φ → ττ) ≈ 4.2 pb and σexcl.(gg →∅→ ττ) ≈ 6.8 pb at mφ = 170 GeV and σexcl.(bb → φ → ττ) ≈ 9.2 fb and σexcl.(gg → φ → ττ) ≈10 fb at m∅ = 1000 GeV.
The search significantly improves upon the sensitivity of previous searches, and leads the sensitivity of the h/H/A → ττ combined search, where other tau decay modes are selected in the final state, for signal masses mA >∼ 350 GeV.
As no significant excess is found, exclusion limits are set in the space of the two leading-order free parameters of the MSSM, mA and tanβ. After the discovery of a Higgs boson in 2012, with a mass of mH = 125.09 ± 0.24 GeV, new phenomenological scenarios of the MSSM were proposed. In this search, exclusion limits are obtained for these various scenarios in the mass range mA = 170 - 1000 GeV. Model-independent exclusion limits were also obtained for the cross-section of the production of a generic resonance, φ, by bb annihilation and gluon-gluon fusion. Excluded cross-sections at 95% confidence level are as high as σexcl.(bb→ φ → ττ) ≈ 4.2 pb and σexcl.(gg →∅→ ττ) ≈ 6.8 pb at mφ = 170 GeV and σexcl.(bb → φ → ττ) ≈ 9.2 fb and σexcl.(gg → φ → ττ) ≈10 fb at m∅ = 1000 GeV.
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BONN-IR ; 2016-04Scutti, Federico: Search for Neutral Higgs Bosons of the MSSM decaying to τhad τhad in proton-proton collisions at √s = 8 TeV with the ATLAS detector. - Bonn, 2016. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-44617
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-44617
@phdthesis{handle:20.500.11811/6874,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-44617,
author = {{Federico Scutti}},
title = {Search for Neutral Higgs Bosons of the MSSM decaying to τhad τhad in proton-proton collisions at √s = 8 TeV with the ATLAS detector},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2016,
month = nov,
volume = 2016-04,
note = {A search for the neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model, h, H and A, is presented in this thesis. It is based on a data sample with an integrated luminosity of Lint = 19:5 fb-1 from proton-proton collisions with a center-of-mass energy of √s = 8 TeV produced at the LHC and recorded by the ATLAS experiment in 2012. The search is performed in the decay channel with two tau leptons decaying hadronically, h/H/A → τhad τhad. The selection of events is based on the kinematic and topological properties of a heavy neutral Higgs boson produced by bb annihilation and the gluon-gluon fusion production mechanisms.
The search significantly improves upon the sensitivity of previous searches, and leads the sensitivity of the h/H/A → ττ combined search, where other tau decay modes are selected in the final state, for signal masses mA >∼ 350 GeV.
As no significant excess is found, exclusion limits are set in the space of the two leading-order free parameters of the MSSM, mA and tanβ. After the discovery of a Higgs boson in 2012, with a mass of mH = 125.09 ± 0.24 GeV, new phenomenological scenarios of the MSSM were proposed. In this search, exclusion limits are obtained for these various scenarios in the mass range mA = 170 - 1000 GeV. Model-independent exclusion limits were also obtained for the cross-section of the production of a generic resonance, φ, by bb annihilation and gluon-gluon fusion. Excluded cross-sections at 95% confidence level are as high as σexcl.(bb→ φ → ττ) ≈ 4.2 pb and σexcl.(gg →∅→ ττ) ≈ 6.8 pb at mφ = 170 GeV and σexcl.(bb → φ → ττ) ≈ 9.2 fb and σexcl.(gg → φ → ττ) ≈10 fb at m∅ = 1000 GeV.},
url = {https://hdl.handle.net/20.500.11811/6874}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-44617,
author = {{Federico Scutti}},
title = {Search for Neutral Higgs Bosons of the MSSM decaying to τhad τhad in proton-proton collisions at √s = 8 TeV with the ATLAS detector},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2016,
month = nov,
volume = 2016-04,
note = {A search for the neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model, h, H and A, is presented in this thesis. It is based on a data sample with an integrated luminosity of Lint = 19:5 fb-1 from proton-proton collisions with a center-of-mass energy of √s = 8 TeV produced at the LHC and recorded by the ATLAS experiment in 2012. The search is performed in the decay channel with two tau leptons decaying hadronically, h/H/A → τhad τhad. The selection of events is based on the kinematic and topological properties of a heavy neutral Higgs boson produced by bb annihilation and the gluon-gluon fusion production mechanisms.
The search significantly improves upon the sensitivity of previous searches, and leads the sensitivity of the h/H/A → ττ combined search, where other tau decay modes are selected in the final state, for signal masses mA >∼ 350 GeV.
As no significant excess is found, exclusion limits are set in the space of the two leading-order free parameters of the MSSM, mA and tanβ. After the discovery of a Higgs boson in 2012, with a mass of mH = 125.09 ± 0.24 GeV, new phenomenological scenarios of the MSSM were proposed. In this search, exclusion limits are obtained for these various scenarios in the mass range mA = 170 - 1000 GeV. Model-independent exclusion limits were also obtained for the cross-section of the production of a generic resonance, φ, by bb annihilation and gluon-gluon fusion. Excluded cross-sections at 95% confidence level are as high as σexcl.(bb→ φ → ττ) ≈ 4.2 pb and σexcl.(gg →∅→ ττ) ≈ 6.8 pb at mφ = 170 GeV and σexcl.(bb → φ → ττ) ≈ 9.2 fb and σexcl.(gg → φ → ττ) ≈10 fb at m∅ = 1000 GeV.},
url = {https://hdl.handle.net/20.500.11811/6874}
}
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