Search for the standard model Higgs boson in the decay channel H→ZZ→4l in pp collisions at √s=7TeV

Abstract

A search for a Higgs boson in the four-lepton decay channel H→ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range of 110 < m H < 600GeV. The analysis uses data corresponding to an integrated luminosity of 4.7fb -1 recorded by the CMS detector in pp collisions at √s=7TeV from the LHC. Seventy-two events are observed with four-lepton invariant mass m 4- > 100GeV (with 13 below 160GeV), while 67.1±6.0 (9.5±1.3) events are expected from background. The four-lepton mass distribution is consistent with the expectation of standard model background production of ZZ pairs. Upper limits at 95% confidence level exclude the standard model Higgs boson in the ranges of 134-158GeV, 180-305GeV, and 340-465GeV. Small excesses of events are observed around masses of 119, 126, and 320GeV, making the observed limits weaker than expected in the absence of a signal. © 2012 CERN.