Searches For The Exclusive Higgs and the Charged Higgs Bosons with the ATLAS Detector at the LHC
Abstract
In this thesis, searches for the exclusive Standard Model (SM) and charged
hMSSM Higgs bosons are performed. While observations of the SM Higgs boson
in 2012 by ATLAS and CMS collaborations were ground-breaking, several of the
SM Higgs boson properties such as its coupling strengths and branching ratios of
its decays still carry large systematic uncertainties. Higgs boson candidates from
exclusive production could lower these systematic uncertainties due to their cleaner
production environment, improving knowledge of the SM Higgs boson sector. Since
the charged Higgs boson is not included in the SM, its evidence would clearly indicate
physics beyond the SM which could address the hierarchy problem. Since no signal is
observed for either of these bosons, limits to their production cross sections are set.
A 95% confidence-level upper limit on the total production cross-section for exclusive
Higgs boson is set to 1.2 pb. Limits on the total production cross section of the charged Higgs boson times its branching ratio to τ ν are set between 1.9 pb and 15 fb,
for charged Higgs boson masses ranging from 200 to 2000 GeV.