CMS-PAS-HIG-13-002

CMS-PAS-HIG-13-002
Properties of the Higgs-like boson in the decay H to ZZ to 4l in pp collisions at sqrt s =7 and 8 TeV
CMS Collaboration
2013

Abstract: The properties of the new boson with the mass around 125 GeV are reported. The boson is observed in the search for the standard model Higgs boson in the mass range < m_H < 1000$ GeV in the H $\rightarrow$ ZZ decay channel. The search considers final states where both Z's decay to electron, muon, or tau lepton pairs. The analysis uses pp collision data recorded by the CMS detector at the LHC, corresponding to integrated luminosities of 5.1 ${\rm fb}^{-1}$ at $\sqrt{s} = 7$ TeV and 19.6 ${\rm fb}^{-1}$ at $\sqrt{s}= 8$ TeV. It makes use of the measured four-lepton mass, the mass uncertainty, kinematic discriminants, and information sensitive to the production mechanism, such as associated dijet characteristics and transverse momentum of the four-lepton system. The boson is observed in channels with electron and muon pairs with a local significance above the expected background of 6.7 standard deviations with the mass .8 \pm 0.5$ (stat.) $\pm 0.2$ (syst.)~GeV. The signal strength $\mu$, relative to the expectation for the standard model Higgs boson, is measured to be $\mu = 0.91^{+ 0.30}_{-0.24}$. The signal strength modifiers associated with vector bosons and fermions in production are measured to be$\mu_V = 1.0^{+2.4}_{-2.3}$ and $\mu_F = 0.9^{+0.5}_{-0.4}$, thus consistent with the standard model expectations. The spin-parity of the boson is studied and the pure scalar hypothesis is found to be consistent with the observation when compared to six other spin-parity hypotheses. The data disfavour the pure pseudoscalar hypothesis ^-$ with a $\mathrm{CL_s}$ value of 0.16\%, and disfavour the pure spin-2 hypothesis of a narrow resonance with the minimal couplings to the vector bosons with a $\mathrm{CL_s}$ value of 1.5\%. The spin-1 hypotheses are disfavoured with an even higher confidence. No other significant standard model Higgs-like excess is found in the search and upper limits at 95\% confidence level exclude the range 130--827~GeV.
Links: CDS record (PDF) ; inSPIRE record ; Public twiki page ; CADI line (restricted) ; These preliminary results are superseded in this paper, PRD 89 (2014) 092007. The superseded preliminary plots can be found here.

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