A search for the Higgs Boson in H -> ZZ -> 4l mode

Abstract

A search for a Higgs boson in the decay channel ${\rm H} \rightarrow {\rm ZZ}^{(*)}$ with each Z boson decaying to an electron or muon pair is presented using pp collisions from the LHC at $\sqrt s$ = 7 TeV. The data analyzed correspond to an integrated luminosity of $1.13 \pm 0.07$ fb$^{-1}$ recorded by the CMS detector in 2010 and 2011. The search covers Higgs boson mass ($m_{\rm H}$) hypotheses of $110 < m_{\rm H} < 600 \GeVcc$. Fifteen events are observed, while $14.4 \pm 0.6$ events are expected from standard model background processes. Upper limits at 95% CL on the cross section$\times$branching ratio for a Higgs boson with standard model-like decays exclude cross sections from about one to two times the expected standard model cross section for masses in the range $180 < m_{\rm H} < 420 \GeVcc$. Reinterpreted in the context of the standard model with four fermion families a Higgs boson with a mass in the range 138 -162 $\GeVcc$ and 178-502 $\GeVcc$ is excluded at 95% CL.