Search for the Standard Model Higgs Boson in the Decay Channel H → ZZ → 4l in pp Collisions at √s = 7 TeV

Authors

S. Chatrchyan, Yerevan Physics Institute, Yerevan, Armenia
Ekaterina Avdeeva, University of Nebraska-LincolnFollow
Kenneth A. Bloom, University of Nebraska-LincolnFollow
S. Bose, University of Nebraska-LincolnFollow
J. Butt, University of Nebraska-Lincoln
Daniel R. Claes, University of Nebraska-LincolnFollow
Aaron Dominguez, University of Nebraska-LincolnFollow
Michael Eads, University of Nebraska-LincolnFollow
P. Jindal, University of Nebraska-Lincoln
J. Keller, University of Nebraska-LincolnFollow
Ilya Kravchenko, University of Nebraska-LincolnFollow
J. Lazo-Flores, University of Nebraska-LincolnFollow
H. Malbouisson, University of Nebraska-Lincoln
Sudhir Malik, University of Nebraska-LincolnFollow
Gregory Snow, University of Nebraska-LincolnFollow

Date of this Version

2012

Citation

PHYSICAL REVIEW LETTERS 108, 111804 (2012); DOI: 10.1103/PhysRevLett.108.111804

Comments

Copyright 2012 CERN, for the CMS Collaboration

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 < 600 GeV. The analysis uses data corresponding to an integrated luminosity of 4.7 fb^-1 recorded by the CMS detector in pp collisions at √s = 7 TeV from the LHC. Seventy- two events are observed with four-lepton invariant mass m_4ℓ > 100 GeV (with 13 below 160 GeV), 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 134–158 GeV, 180–305 GeV, and 340–465 GeV. Small excesses of events are observed around masses of 119, 126, and 320 GeV, making the observed limits weaker than expected in the absence of a signal.