Search for a Standard Model Higgs boson in the H->ZZ->llnunu decay channel with the ATLAS detector

TL;DR

This paper reports a search for a Standard Model Higgs boson decaying into ZZ to llnu using ATLAS data at 7 TeV, setting exclusion limits in the mass range 340-450 GeV based on 1.04 fb^-1 of data.

Contribution

First search for H->ZZ->llnunu decay channel with ATLAS at 7 TeV, establishing exclusion limits in the 340-450 GeV mass range.

Findings

No significant excess observed over background.

Excluded Higgs mass range 340-450 GeV at 95% CL.

Data consistent with Standard Model background expectations.

Abstract

A search for a heavy Standard Model Higgs boson decaying via H->ZZ->llnunu, where l=e,mu, is presented. It is based on proton-proton collision data at sqrt(s)=7 TeV, collected by the ATLAS experiment at the LHC in the first half of 2011 and corresponding to an integrated luminosity of 1.04 fb^-1. The data are compared to the expected Standard Model backgrounds. The data and the combined background expectations are found to be in agreement and upper limits are placed on the Higgs boson production cross section over the entire mass window considered; in particular the production of a Standard Model Higgs boson is excluded in the region 340 < m_H < 450 GeV at the 95% confidence level.