The Search for a Heavy Higgs Boson in the H → W W → lνjj Channel with the ATLAS Detector

A search for a heavy Higgs boson has been performed in the H → W W → lνjj decay channel using the ATLAS detector, with 20.3 fb−1 of data, recorded from proton – proton collisions at the Large Hadron Collider at √s = 8 TeV. The search is performed in two orthogonal search modes, one targeted at gluon-gluon fusion production (ggF) and the other at vector boson fusion (VBF) production. The data are tested against multiple signal hypothesis, one large width Standard Model-like Higgs, one assuming an electroweak singlet (EWS) extension to the SM Higgs sector, and finally, one model independent Higgs, which is generated with the Narrow Width Approximation – consistent with some parameters of EWS and Two Higgs Doublet Models (2HDM). In all cases, no significant excess in the data is found when compared to the background only (SM) hypothesis. Instead, upper limits on σ × B.R. at the 95% confidence level (using the CLs method) are presented for the three heavy Higgs models studied.