Search for Neutral Higgs Bosons Decaying to Tau Pairs in pp Collisions at sqrt(s)=7 TeV

This is a condensed description with plots for the analysis CMS-HIG-11-020

Abstract

A search for neutral Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 1.6/fb recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs, including the cases where the Higgs boson is produced in association with a b-quark jet (MSSM search) or two forward jets from vector boson fusion Higgs boson production (SM search). No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent new bounds in the MSSM parameter space.

Main Results

A measurement of this search are the 95% CL limits on the standard model cross section and the 95% exclusion limit in the MSSM tan beta - ma plane.

SM Higgs boson limit table

mass -95% -68% median +68% +95% obs
110 3.1 3.9 5.4 7.8 11.0 6.0
115 3.3 4.4 6.1 8.7 11.8 7.0
120 3.1 4.0 5.6 8.0 11.1 7.6
125 3.1 4.0 5.7 8.1 11.2 7.1
130 3.4 4.6 6.4 9.2 12.7 10.0
135 4.2 5.4 7.4 10.6 14.5 10.4
140 5.2 6.5 9.1 12.9 17.8 12.4
145 7.1 9.0 12.5 17.7 24.4 17.9

MSSM Higgs boson limit table

mass -95% -68% median +68% +95% obs tan beta exp tan beta obs
90 9.2 12.4 17.8 24.9 34.6 14.1 9.6 8.5
100 6.2 8.6 12.6 18.3 24.7 8.0 10.0 7.9
120 2.9 4.1 6.0 8.4 11.2 4.5 10.1 8.7
130 2.6 3.4 4.8 6.9 9.3 4.1 8.8 7.8
140 1.9 2.6 3.7 5.1 6.9 3.8 10.7 11.0
160 1.5 1.9 2.6 3.7 5.0 3.1 11.7 12.7
180 0.94 1.3 1.9 2.6 3.5 2.3 12.7 14.0
200 0.70 1.1 1.5 2.2 2.9 2.4 14.4 17.7
250 0.52 0.70 0.96 1.4 1.8 1.7 18.6 24.5
300 0.37 0.47 0.66 0.96 1.3 1.2 23.8 31.7
400 0.21 0.26 0.38 0.54 0.73 0.60 36.3 44.8
450 0.13 0.21 0.29 0.42 0.58 0.42 43.4 50.6
500 0.17 0.21 0.25 0.33 0.46 0.34 52.7 59.5

Figures from CMS-HIG-11-020

Figure Links Description
Figure 1 pdf,png Visible mass in the e-tau channel, in the no b-Tag category.
Figure 2 pdf,png Visible mass in the mu-tau channel, in the no b-Tag category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 3 pdf,png Visible mass in the e-mu channel, in the no b-Tag category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 4 pdf, png Visible mass in the e-tau channel, in the b-Tag category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 5 pdf, png Visible mass in the mu-tau channel, in the b-Tag category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 6 pdf,png Visible mass in the e-mu channel, in the b-Tag category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 7 pdf, png Visible mass in the e-tau channel, in the Non-VBF category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 8 pdf,png Visible mass in the mu-tau channel, in the Non-VBF category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 9 pdf,png Visible mass in the e-mu channel, in the Non-VBF category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 10 pdf, png Visible mass in the e-tau channel, in the VBF category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 11 pdf, png Visible mass in the mu-tau channel, in the VBF category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 12 pdf, png Visible mass in the e-mu channel, in the VBF category. The MC histograms have been normalized to the number of the expected events after the fit.
Figure 13 pdf, png The expected one- and two-standard-deviation ranges and observed 95% CL upper limits on cross section time normalized to the SM expectation as a function of mH.
Figure 14 pdf,png The expected one- and two-standard-deviation ranges and observed 95% CL upper limits on cross section times branching fraction as a function of mA. The signal acceptance is based on the MSSM model described in the text, assuming tan beta=30.
Figure 15 pdf,png Region in the parameter space of tan beta versus mA excluded at 95% CL in the context of the MSSM m^max_h scenario, with the effect of +/- 1 sigma theoretical uncertainties shown. The other shaded regions show the 95% CL excluded regions from the LEP and Tevatron experiments.

Additional plots for public talks

Figure 16 pdf,png Reconstructed number of jets in the e-mu channel
Figure 17 pdf,png econstructed number of b-tagged jets in the e-mu channel
Figure 18 pdf,png Distribution of the b-tag discriminator in the e-mu channel
Figure 19 pdf,png Distribution of the di-Jet invariant mass for the two VBF jets in the e-mu channel
Figure 20 pdf,png Delta eta distribution of the two VBF jets in the e-mu channel
Figure 21 pdf,png Distribution of the (Pmiss - 0.85 Pvis) variable in the e-mu channel
Figure 22 pdf,png Distribution of the (Pzeta - 1.5*Pvis) variable for opposite sign mu-tau pairs, Pzeta = Pmiss + Pvis. No scale factors have been used from the Monte Carlo samples, this figure is intended only for illustrative purpose to show the OS / SS method for background estimation.
Figure 23 pdf,png Distribution of the (Pzeta - 1.5*Pvis) variable for same sign mu-tau pairs, Pzeta = Pmiss + Pvis.

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Topic revision: r7 - 2011-09-15 - MarkusKlute
 
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