Searches for high mass Higgs bosons with the ATLAS detector

S Angelidakis

doi:10.1016/j.nuclphysbps.2016.12.038

Abstract

Recent results from searches for heavy Higgs bosons, using the ATLAS detector at the CERN LHC are presented. The searches use proton–proton collision data collected during the second running period of the LHC (LHC Run-II), at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 3.2 fb−1. The results are interpreted in a range of scenarios, including theories beyond the Standard Model of particle physics, and extend the upper limits set during LHC Run-I toward higher mass regions.

Highlights

The discovery of a new particle with a mass of about 125 GeV by the ATLAS [1] and CMS [2] experiments at the Large Hadron Collider (LHC) [3], which was announced in July 2012 [4, 5], provided, by all experimental evidence so far, an excellent candidate for the Higgs boson predicted by the Standard Model (SM) of particle physics [6, 7, 8]
The results presented have been produced u√sing the data collected with ATLAS during 2015, at s = 13 TeV, which correspond to an integrated luminosity of 3.2 fb−1
The red curves show the observed and expected exc√lusion limits from LHC Run-I analyses of pp collisions recorded at s = 8 TeV by ATLAS

Summary

Introduction

The discovery of a new particle with a mass of about 125 GeV by the ATLAS [1] and CMS [2] experiments at the Large Hadron Collider (LHC) [3], which was announced in July 2012 [4, 5], provided, by all experimental evidence so far, an excellent candidate for the Higgs boson predicted by the Standard Model (SM) of particle physics [6, 7, 8]. One important remaining question is whether or not the newly discovered particle is part of an extended scalar sector as postulated by various extensions to the SM such as the two-Higgsdoublet model (2HDM) [9] and the Minimal Supersymmetric Standard Model (MSSM) [10] These models predict additional Higgs bosons, motivating searches at masses other than 125 GeV. The analysis is divided into two main channels; the resolved analysis attempts to reconstruct and identify two separate hadronic jets from the Z → qq decay whereas the merged analysis implements boosted techniques, evaluating the jet-substructure, in order to identify a Z → qq decay that has been reconstructed as a single largeradius (large-R) jet The latter is expected when the resonance mass is significantly higher than the Z boson mass. / Nuclear and Particle Physics Proceedings 00 (2016) 1–6 σ(gg → H) x BR(H → ZZ) [pb]

10 ATLAS Preliminary

30 Run 1 result

Findings

10. Conclusions