Combined results of searches for the standard model Higgs boson in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports combined search results for the standard model Higgs boson in proton-proton collisions at 7 TeV across five decay modes, setting exclusion limits and observing a potential signal near 124 GeV.

Contribution

It provides the first combined analysis of multiple decay channels at 7 TeV, extending the Higgs mass exclusion range and identifying a potential Higgs signal around 124 GeV.

Findings

Excluded Higgs mass range: 127-600 GeV at 95% CL

Observed excess at 124 GeV with 3.1 sigma local significance

Global significance of excess: 1.5 to 2.1 sigma

Abstract

Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.