# 2014 CAP Congress / Congrès de l'ACP 2014

15-20 June 2014
Laurentian University / Université Laurentienne
America/Toronto timezone
Welcome to the 2014 CAP Congress! / Bienvenue au congrès de l'ACP 2014!

## Search for Standard Model Higgs boson production in association with a top quark pair in the four lepton signature with the ATLAS detector

17 Jun 2014, 10:15
15m
C-112 (Laurentian University / Université Laurentienne)

### C-112

#### Laurentian University / Université Laurentienne

Sudbury, Ontario
Oral (Student, Not in Competition) / Orale (Étudiant(e), pas dans la compétition) Particle Physics / Physique des particules (PPD)

### 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.

### Primary author

David Anthony Demarco (University of Toronto (CA))

 Slides