Search for a Standard Model Higgs boson in the mass range 200-600 GeV in the H->ZZ->llqq decay channel

TL;DR

This paper reports a search for a heavy Standard Model Higgs boson in the 200-600 GeV mass range using the H->ZZ->llqq decay channel with data from the ATLAS detector, setting exclusion limits but finding no significant signal.

Contribution

First search in the H->ZZ->llqq channel at 7 TeV for Higgs masses 200-600 GeV, providing new exclusion limits based on 4.7 fb^-1 of data.

Findings

No significant excess observed above background.

Excluded Higgs mass ranges between 300-322 GeV and 353-410 GeV at 95% CL.

Set upper limits on Higgs production cross section.

Abstract

A search for a heavy Standard Model Higgs boson decaying via H->ZZ->llqq, where l=e or mu, is presented. The search uses a data set of pp collisions at sqrt(s) = 7 TeV, corresponding to an integrated luminosity of 4.7 fb^-1 collected in 2011 by the ATLAS detector at the CERN LHC. No significant excess of events above the estimated background is found. Upper limits at 95% confidence level on the production cross section of a Higgs boson with a mass in the range between 200 and 600 GeV are derived. A Standard Model Higgs boson with a mass in the range 300 <= mH <= 322 GeV or 353 <= mH <= 410 GeV is excluded at 95% CL. The corresponding expected exclusion range is 351 <= mH <= 404 GeV at 95% CL.