Searches for the SM Higgs Boson via VBF production processes in the di-τ channel

This page contains approved plots and results in the order as they appear in the CSC note. Only the CSC note contains all the relevant information and should thus be consulted if one of the plots is used.

Figure 1: Reconstruction and identification efficiency of the hadronic tau (a) and the jet-fake rejection efficiency (b) as a function of p_T, respectively.

Figure 2: Pseudorapidity of the highest p_T (a) and the second highest p_T (b) jets for the Cone jet algorithm based on TopoClusters with R = 0.4 in VBF H->ττ->μμ (mH =120 GeV) and background events. Only p_T cuts were applied to jets. Solid (black) histogram is for signal, dashed (red) histogram is for tt->WW->(μμ), and dotted (blue) histogram is for Z->μμ+n jets.

Figure 3: Jet reconstruction efficiency for the Cone jet algorithm with R = 0.4 as a function of the generator-level jet p_T for the jets based on TopoClusters (a) and η for Tower- and TopoCluster-based jets (b).

Figure 4: Pseudorapidity gap between tag jets (a) and invariant-mass distributions of tag jets (b) in VBF H->ττ->μμ events (mH =120 GeV). A requirement η₁×η₂>=0 is used in addition to the cuts on jet p_T. Solid (black) histogram is for signal, dashed (red) histogram is for tt->WW->(μμ), and dotted (blue) histogram is for Z->μμ+n jets.

Figure 5: Jet multiplicity distribution for the signal, Z+jets, and tt background after requiring the cuts up to the N jets >= 2 level in the list of cuts for the ll channel (see Table 5).

Figure 6: Background rejection versus signal sensitivity for the central jet veto with and without pileup. Also shown is the case for tt-only background.

Figure 7: Central jet veto performance in the presence of varying levels of pileup for signal and background samples.

Figure 8: Efficiency of the b-jet veto as a function of the forward jet p_T in for the signal and tt background.

Figure 9: Transverse momentum of the leptons (a) and missing transverse energy (b) for the two processes rescaled Z->μμ and true Z->ττ->ll+4ν.

Figure 10: Reconstructed invariant mass distribution (a) and its bin-by-bin ratio (b) generated from the true and emulated Z->ττ->lh+3ν events. The gray band represents +/- 10% around a ratio of 1.

Figure 11: Track multiplicity distribution for QCD fake events and electron-fake events as well as the τ signal.

Figure 12: Expected errors of the fraction rtau as a function of luminosity. The QCD events are scaled to ×2 and ×5.

Figure 13: Figures (a) and (b) show the result of a fit to a pure Monte Carlo samples of Z->ττ and signal (mH = 120 GeV) in the lh-channel, respectively. The dashed lines represent the three components of the model and the dotted curve represents the erf() efficiency envelope. These samples do not include pileup.

Figure 14: Figure (a) shows that the shapes are similar for these backgrounds and that the shape is stable in the final stages of the cut flow. The m_ττ spectrum for tt and W +jets backgrounds after all cuts for the ll-channel (b) and lh-channel (c) with a fit to the spectrum. The solid and dashed curves show the result of the simultaneous fit to the control sample and signal candidates with and without the signal contribution, respectively.

Figure 15: Example fits to a data sample with the signal-plus-background (a,c) and background only (b,d) models for the lh- and ll-channels at mH = 120 GeV with 30 fb^-1 of data. Not shown are the control samples that were fit simultaneously to constrain the background shape. The fits are performed to the signal and background expectation (histograms), while the overlaid data with error bars are only indicative of a possible data set. These samples do not include pileup.

Figure 16: Expected signal significance for several masses based on fitting the m_{τ τ} spectrum. Background uncertainties are incorporated by utilizing the profile likelihood ratio. These results do not include the impact of pileup.

Figure 17: The linearity of the fitted mass versus the input mass (a) and the mass resolution versus the input mass (b). These results do not include the impact of pileup, which is discussed in Section 4.7.

Figure 18: The ratio of expected p-values for the floating and fixed mass fits as a function of the Higgs boson mass. This plot summarizes the impact of the 'look-elsewhere' effect in this analysis.

Figure 19: Expected 95% exclusion of the signal rate in units of the Standard Model expectation, μ, as a function of the Higgs boson mass for the ll and lh-channels with 10 fb^-1 of data. The exclusion takes into account the uncertainty on the signal efficiency described in Section 5.

Caption: m_ττ distribution for the hh-channel, where the safety factor 5 for QCD background is not included in the plot.