Search for the Standard Model Higgs boson in the H > WW > lvjj decay channel at √s = 8 TeV

This is a condensed description with plots for the analysis CMS-HIG-12-021

Abstract

A search for the Standard Model Higgs boson decaying to two W bosons with the subsequent decay to a final state containing one lepton, one neutrino, and two jets is presented. The results are based on a data sample corresponding to an integrated luminosity of 5.1 fb⁻¹ of proton-proton collisions at √s = 8 TeV and collected with the CMS detector at the CERN LHC in 2012. Selections to discriminate between the signal and background events are based on kinematic and topological quantities including the angular spin correlations between the decay products. No evidence for the Higgs boson is found. Using 8 TeV data, we exclude the Standard Model Higgs boson in the mass range 260-460 GeV at 95% confidence level. When combined with 7 TeV data, the exclusion range expands to 230-480 GeV at 95% confidence level.

Figures from CMS-HIG-12-021

figure	label	description
	Figure 1 (a) png,pdf	The invariant mass of the di-jet system after the physics object selection but before optimization, for the case of muons 2-jets sample.
	Figure 1 (b) png,pdf	The invariant mass of the four-body system after the physics object selection but before optimization, for the case of muons 2-jets sample.
	Figure 2(top left) png,pdf	Variable Φ used as input for the likelihood discriminant.
	Figure 2(top middle) png,pdf	Variable Φ1 used as input for the likelihood discriminant.
	Figure 2(top right) png,pdf	Variable Θ1 used as input for the likelihood discriminant.
	Figure 2(middle left) png,pdf	Variable Θ2 used as input for the likelihood discriminant.
	Figure 2(middle middle) png,pdf	Variable Θ* used as input for the likelihood discriminant.
	Figure 2(middle right) png,pdf	Variable pT(WW) used as input for the likelihood discriminant.
	Figure 2(bottom left) png,pdf	Rapidity of the WW system used as input for the likelihood discriminant.
	Figure 2(bottom middle) png,pdf	Likelihood discriminant for muon plus 2 jet channel with selection optimized for Higgs mass hypothesis 190 GeV.
	Figure 2(bottom right) png,pdf	Likelihood discriminant for muon plus 2 jet channel with selection optimized for Higgs mass hypothesis 500 GeV.
	Figure 3(a) png pdf, Figure 3(b) png pdf, Figure 3(c) png pdf	The di-jet invariant mass distribution with the fit projections, for the muon 2-jet category, after selections optimized for the Higgs mass hypotheses of 200 GeV (a), 300 GeV (b), and 500 GeV (c). The fit doesn't include data points in the test region between the vertical lines.
	Figure 4(a) png pdf, Figure 4(b) png pdf, Figure 4(c) png pdf	The distribution of the extrapolated background shape in the signal region for the Higgs mass hypothesis of 200 GeV (a), 300 GeV (b), and 500 GeV (c), for muon 2-jets category. The black markers represent the extrapolated points, while the blue curve is the smooth parametrization using an exponential function. The dashed bands show the envelope of the systematic uncertainty in the shape extrapolation.
	Figure 5(a) png pdf	The WW invariant mass distribution with the fit projections, for the muon 2-jet category, after selection optimized for the Higgs mass hypotheses of 200 GeV.
	Figure 5(b) png pdf	The WW invariant mass distribution with the fit projections, for the muon 2-jet category, after selection optimized for the Higgs mass hypotheses of 300 GeV.
	Figure 6 png pdf	The WW invariant mass distribution with the fit projections, for the muon 2-jet category, after selection optimized for the Higgs mass hypotheses of 500 GeV.
	Figure 6(a) png pdf	Observed (solid) and expected (dashed) 95% CL upper limit on the ratio of the production cross section to the SM expectation for the Higgs boson obtained using the asymptotic CLS technique. The 68% and 95% ranges of expectation for the background-only model are also shown with green and yellow bands, respectively. The solid line at 1 indicates the SM expectation. Limit derived from 8 TeV data is shown.
	Figure 6(b) png pdf	Observed (solid) and expected (dashed) 95% CL upper limit on the ratio of the production cross section to the SM expectation for the Higgs boson obtained using the asymptotic CLS technique. The 68% and 95% ranges of expectation for the background-only model are also shown with green and yellow bands, respectively. The solid line at 1 indicates the SM expectation. The combined limit using both 7 TeV and 8 TeV data is shown.

Tables from CMS-HIG-12-021

Table 1: Determination of the m_jj shape and normalization. External constraints are assumed Gaussian.

Table 2: Sources of signal systematics considered in the analysis, with the corresponding magnitude, for the limit extraction.

Additional plots for public talks

From Analysis Note AN-2012/193

figure	label	description
	Figure 2 (left) png pdf, Figure 2 (right) png pdf	Comparison of the leading jet (left) and the second jet (right) pT distributions from data and MC for the muon+jets selection.
	Figure 4 (left) png pdf, Figure 4 (right) png pdf	Comparison of the leading jet (left) and the second jet (right) η distributions from data and MC for the muon+jets selection.
	Figure 4 (left) png pdf	Comparison of the muon pT distributions from data and MC for the muon+jets selection.
	Figure 4 (right) png pdf	Comparison of the muon η distributions from data and MC for the muon+jets selection.
	Figure 5 (left) png pdf	Comparison of the distributions from data and MC of the transverse mass of the muon / MET system for the muon+jets selection.
	Figure 5 (right) png pdf	Comparison of the distributions from data and MC of the MET for the muon+jets selection.
	Figure 11 png pdf	Comparison of the dijet mass (mjj) distributions from data and MC for the electron+jets selection.
	Figure 16 png pdf	Comparison of the charge of the muon from data and MC for the muon+jets selection.
	Figure 24 (left) png pdf	Comparison of the four-body invariant mass from data and MC for the electron+jets selection.

-- KalanandMishra - 21-Jun-2012