Search for the standard model higgs boson in the H ? ZZ* ? 4l decay channel with the ATLAS detector

Abstract

The search for the Standard Model Higgs boson in the decay channel H ? ZZ(*) ? l+l-l'+l'-, where l,l' = e or µ, is presented using 4.8 fb-1 and 5.8 fb-1 of proton-proton collision data at centre-of-mass energies of 7 TeV and 8 TeV, respectively, recorded with the ATLAS detector at the Large Hadron Collider. The search is performed for Higgs boson masses between 110 and 600 GeV. The Standard Model Higgs boson is excluded at 95% confidence level in the mass ranges 131- 162 GeV and 170-460 GeV, while the expected exclusion ranges are 124-164 GeV and 176- 500 GeV. An excess of events is observed around mH = 125 GeV, with a local significance of 3.4 standard deviations.