Speaker
David Anthony Demarco
(University of Toronto (CA))
Description
An overview will be presented of a search for the Standard Model Higgs boson produced in association with a top quark pair decaying into the $t\bar{t}H\to 4\ell$ signature. The study has been performed using data with an integrated luminosity of $\mathcal{L}=20.1 fb^{-1}$ collected by the ATLAS experiment in $pp$ collisions with $\sqrt{s}=8$ TeV at the Large Hadron Collider. This production mode provides direct access to the top quark-Higgs coupling and can be beneficial to this measurement, despite its relatively small cross section. The $4\ell$ analysis, which was carried out in combination with analyses of other multi-lepton final states, is sensitive to three Higgs boson decay modes, $H\to W^+W^-$, $H\to\tau^+\tau^-$ and $H\to ZZ$. The majority of the signal comes from the $W^+W^-$ mode, which is probed by requiring that all W bosons (including those from the top quark decays) decay leptonically. This yields a final state signature which includes two bottom quarks, 4 charged leptons and neutrinos (in the form of missing energy). Preliminary plans for future study of this channel during LHC Run 2 will also be presented.
Author
David Anthony Demarco
(University of Toronto (CA))
