Search for the Standard Model Higgs boson in the decay channel H → ZZ(*) → 4l at CMS

A search for the Standard Model (SM) Higgs boson in the decay channel H → ZZ(*) → 4l with each Z boson decaying to an electron or muon pair is presented using pp collisions from the LHC at √s = 7 TeV. The data analysed correspond to an integrated luminosity of 1.66 ±0.07 fb-1 recorded by the CMS detector in 2010 and 2011. The search covers Higgs boson mass (mH) hypotheses of 110 < mH < 600 GeV/c2. Twenty-one events are observed, while 21.2 ± 0.8 events are expected from Standard Model (SM) background processes. The events are not clustered in mass excluding interpretation as the SM Higgs boson and its (4l) mass distribution is consistent with the expectation of SM continuum production of ZZ(*) pairs. Upper limits at 95% CL on the cross-section x branching ratio for a SM Higgs boson with SM like decays exclude cross-sections from about once to twice the expected SM cross-section for masses in the range of 150 < mH < 420 GeV/c2. (author)