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+%\section{Systematics Uncertainties on the Background Prediction}
+%\label{sec:systematics}
-+
+[ADD INTRODUCTORY BLURB ON UNCERTAINTIES \\
-+
+ADD COMPARISONS OF ALL THE ALTERNATIVE SAMPLES FOR ALL THE SIGNAL
-+
+REGIONS \\
-+
+LIST ALL THE UNCERTAINTIES INCLUDED AND THEIR VALUES]
-+
+\subsection{Uncertainty on the \ttll\ Acceptance}
+The \ttbar\ background prediction is obtained from MC, with corrections
+  Pythia (LO). It may also be noted that MC@NLO uses Herwig6 for the
+  hadronisation, while POWHEG uses Pythia6.
+\item Modeling of taus: The alternative sample does not include
-<
+  Tauola and is otherwise identical to the Powheg sample.
->
+  Tauola and is otherwise identical to the Powheg sample.  [DONE AT
->
+TEV AND FOUND TO BE NEGLIGIBLE]
+\item The PDF uncertainty is estimated following the PDF4LHC
+  recommendations[CITE]. The events are reweighted using alternative
+  PDF sets for CT10 and MSTW2008 and the uncertainties for each are derived using the
+  addition, the NNPDF2.1 set with 100 replicas. The central value is
+  determined from the mean and the uncertainty is derived from the
+  $1\sigma$ range. The overall uncertainty is derived from the envelope of the
-<
+  alternative predictions and their uncertainties.
->
+  alternative predictions and their uncertainties. [DONE AT 7 TEV AND
->
+  FOUND TO BE NEGLIGIBLE]
+\end{itemize}
+        \includegraphics[width=0.8\linewidth]{plots/n_dl_syst_comp.png}
+        \caption{
+          \label{fig:ttllsyst}%\protect
-<
+          Central Prediction
-<
+          Band:
-<
+          - total stat. error for all Data and MC samples
-<
+          - N jets scaling uncertainty (ISR/FSR)
-<
+          Alternative Sample Predictions
-<
+          Error bars: uncorrelated stat. error from alternative ttbar sample only}
->
+          Comparison of the \ttll\ central prediction with those using
->
+          alternative MC samples. The blue band corresponds to the
->
+          total statistical error for all data and MC samples. The
->
+          alternative sample predictions are indicated by the
->
+          datapoints. The uncertainties on the alternative predictions
->
+          correspond to the uncorrelated statistical uncertainty from
->
+          the size of the alternative sample only.}
+      \end{center}
+    \end{figure}
+%\end{tabular}
+%\end{center}
+%\end{table}
-+
-+
-+
+\subsection{Isolated Track Veto: Tag and Probe Studies}
-+
-+
+[EVERYTHING IS 7TEV HERE, UPDATE WITH NEW RESULTS \\
-+
+ADD TABLE WITH FRACTION OF EVENTS THAT HAVE A TRUE ISOLATED TRACK]
-+
-+
+In this section we compare the performance of the isolated track veto in data and MC using tag-and-probe studies
-+
+with samples of Z$\to$ee and Z$\to\mu\mu$. The purpose of these studies is to demonstrate that the efficiency
-+
+to satisfy the isolated track veto requirements is well-reproduced in the MC, since if this were not the case
-+
+we would need to apply a data-to-MC scale factor in order to correctly predict the \ttll\ background. This study
-+
+addresses possible data vs. MC discrepancies for the {\bf efficiency} to identify (and reject) events with a
-+
+second {\bf genuine} lepton (e, $\mu$, or $\tau\to$1-prong). It does not address possible data vs. MC discrepancies
-+
+in the fake rate for rejecting events without a second genuine lepton; this is handled separately in the top normalization
-+
+procedure by scaling the \ttlj\ contribution to match the data in the \mt\ peak after applying the isolated track veto.
-+
+Furthermore, we test the data and MC
-+
+isolated track veto efficiencies for electrons and muons since we are using a Z tag-and-probe technique, but we do not
-+
+directly test the performance for hadronic tracks from $\tau$ decays. The performance for hadronic $\tau$ decay products
-+
+may differ from that of electrons and muons for two reasons. First, the $\tau$ may decay to a hadronic track plus one
-+
+or two $\pi^0$'s, which may decay to $\gamma\gamma$ followed by a photon conversion. As shown in Figure~\ref{fig:absiso},
-+
+the isolation distribution for charged tracks from $\tau$ decays that are not produced in association with $\pi^0$s are
-+
+consistent with that from $\E$s and $\M$s. Since events from single prong $\tau$ decays produced in association with
-+
+$\pi^0$s comprise a small fraction of the total sample, and since the kinematics of $\tau$, $\pi^0$ and $\gamma\to e^+e^-$
-+
+decays are well-understood, we currently demonstrate that the isolation is well-reproduced for electrons and muons only.
-+
+Second, hadronic tracks may undergo nuclear interactions and hence their tracks may not be reconstructed.
-+
+As discussed above, independent studies show that the MC reproduces the hadronic tracking efficiency within 4\%,
-+
+leading to a total background uncertainty of less than 0.5\% (after taking into account the fraction of the total background
-+
+due to hadronic $\tau$ decays with \pt\ $>$ 10 GeV tracks), and we hence regard this effect as neglgigible.
-+
-+
+The tag-and-probe studies are performed in the full 2011 data sample, and compared with the DYJets madgraph sample.
-+
+All events must contain a tag-probe pair (details below) with opposite-sign and satisfying the Z mass requirement 76--106 GeV.
-+
+We compare the distributions of absolute track isolation for probe electrons/muons in data vs. MC. The contributions to
-+
+this isolation sum are from ambient energy in the event from underlying event, pile-up and jet activitiy, and hence do
-+
+not depend on the \pt\ of the probe lepton. We therefore restrict the probe \pt\ to be $>$ 30 GeV in order to suppress
-+
+fake backgrounds with steeply-falling \pt\ spectra. To suppress non-Z backgrounds (in particular \ttbar) we require
-+
+\met\ $<$ 30 GeV and 0 b-tagged events.
-+
+The specific criteria for tags and probes for electrons and muons are:
-+
-+
+%We study the isolated track veto efficiency in bins of \njets.
-+
+%We are interested in events with at least 4 jets to emulate the hadronic activity in our signal sample. However since
-+
+%there are limited statistics for Z + $\geq$4 jet events, we study the isolated track performance in events with
-+
-+
-+
+\begin{itemize}
-+
+  \item{Electrons}
-+
-+
+    \begin{itemize}
-+
+    \item{Tag criteria}
-+
-+
+      \begin{itemize}
-+
+      \item Electron passes full analysis ID/iso selection
-+
+      \item \pt\ $>$ 30 GeV, $|\eta|<2.5$
-+
-+
+      \item Matched to 1 of the 2 electron tag-and-probe triggers
-+
+        \begin{itemize}
-+
+        \item \verb=HLT_Ele17_CaloIdVT_CaloIsoVT_TrkIdT_TrkIsoVT_SC8_Mass30_v*=
-+
+        \item \verb=HLT_Ele17_CaloIdVT_CaloIsoVT_TrkIdT_TrkIsoVT_Ele8_Mass30_v*=
-+
+        \end{itemize}
-+
+      \end{itemize}
-+
-+
+    \item{Probe criteria}
-+
+      \begin{itemize}
-+
+      \item Electron passes full analysis ID selection
-+
+      \item \pt\ $>$ 30 GeV
-+
+      \end{itemize}
-+
+      \end{itemize}
-+
+  \item{Muons}
-+
+    \begin{itemize}
-+
+    \item{Tag criteria}
-+
+      \begin{itemize}
-+
+      \item Muon passes full analysis ID/iso selection
-+
+      \item \pt\ $>$ 30 GeV, $|\eta|<2.1$
-+
+      \item Matched to 1 of the 2 electron tag-and-probe triggers
-+
+        \begin{itemize}
-+
+        \item \verb=HLT_IsoMu30_v*=
-+
+        \item \verb=HLT_IsoMu30_eta2p1_v*=
-+
+        \end{itemize}
-+
+      \end{itemize}
-+
+    \item{Probe criteria}
-+
+      \begin{itemize}
-+
+      \item Muon passes full analysis ID selection
-+
+      \item \pt\ $>$ 30 GeV
-+
+      \end{itemize}
-+
+    \end{itemize}
-+
+\end{itemize}
-+
-+
+The absolute track isolation distributions for passing probes are displayed in Fig.~\ref{fig:tnp}. In general we observe
-+
+good agreement between data and MC. To be more quantitative, we compare the data vs. MC efficiencies to satisfy
-+
+absolute track isolation requirements varying from $>$ 1 GeV to $>$ 5 GeV, as summarized in Table~\ref{tab:isotrk}.
-+
+In the $\geq$0 and $\geq$1 jet bins where the efficiencies can be tested with statistical precision, the data and MC
-+
+efficiencies agree within 7\%, and we apply this as a systematic uncertainty on the isolated track veto efficiency.
-+
+For the higher jet multiplicity bins the statistical precision decreases, but we do not observe any evidence for
-+
+a data vs. MC discrepancy in the isolated track veto efficiency.
-+
-+
-+
+%This is because our analysis requirement is relative track isolation $<$ 0.1, and m
-+
+%This requirement is chosen because most of the tracks rejected by the isolated
-+
+%track veto have a \pt\ near the 10 GeV threshold, and our analysis requirement is relative track isolation $<$ 1 GeV.
-+
-+
+\begin{figure}[hbt]
-+
+  \begin{center}
-+
+        %\includegraphics[width=0.3\linewidth]{plots/el_tkiso_0j.pdf}%
-+
+        %\includegraphics[width=0.3\linewidth]{plots/mu_tkiso_0j.pdf}
-+
+        %\includegraphics[width=0.3\linewidth]{plots/el_tkiso_1j.pdf}%
-+
+        %\includegraphics[width=0.3\linewidth]{plots/mu_tkiso_1j.pdf}
-+
+        %\includegraphics[width=0.3\linewidth]{plots/el_tkiso_2j.pdf}%
-+
+        %\includegraphics[width=0.3\linewidth]{plots/mu_tkiso_2j.pdf}
-+
+        %\includegraphics[width=0.3\linewidth]{plots/el_tkiso_3j.pdf}%
-+
+        %\includegraphics[width=0.3\linewidth]{plots/mu_tkiso_3j.pdf}
-+
+        %\includegraphics[width=0.3\linewidth]{plots/el_tkiso_4j.pdf}%
-+
+        %\includegraphics[width=0.3\linewidth]{plots/mu_tkiso_4j.pdf}
-+
+        \caption{
-+
+          \label{fig:tnp} Comparison of the absolute track isolation in data vs. MC for electrons (left) and muons (right)
-+
+for events with the \njets\ requirement varied from \njets\ $\geq$ 0 to \njets\ $\geq$ 4.
-+
+}
-+
+      \end{center}
-+
+\end{figure}
-+
-+
+\clearpage
-+
-+
+\begin{table}[!ht]
-+
+\begin{center}
-+
+\caption{\label{tab:isotrk} Comparison of the data vs. MC efficiencies to satisfy the indicated requirements
-+
+on the absolute track isolation, and the ratio of these two efficiencies. Results are indicated separately for electrons and muons and for various
-+
+jet multiplicity requirements.}
-+
+\begin{tabular}{l|l|c|c|c|c|c}
-+
+\hline
-+
+\hline
-+
+ e + $\geq$0 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.088 $\pm$ 0.0003   &  0.030 $\pm$ 0.0002   &  0.013 $\pm$ 0.0001   &  0.007 $\pm$ 0.0001   &  0.005 $\pm$ 0.0001  \\
-+
+        mc   &  0.087 $\pm$ 0.0001   &  0.030 $\pm$ 0.0001   &  0.014 $\pm$ 0.0001   &  0.008 $\pm$ 0.0000   &  0.005 $\pm$ 0.0000  \\
-+
+   data/mc   &     1.01 $\pm$ 0.00   &     0.99 $\pm$ 0.01   &     0.97 $\pm$ 0.01   &     0.95 $\pm$ 0.01   &     0.93 $\pm$ 0.01  \\
-+
+\hline
-+
+\hline
-+
+ $\mu$ + $\geq$0 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.087 $\pm$ 0.0002   &  0.031 $\pm$ 0.0001   &  0.015 $\pm$ 0.0001   &  0.008 $\pm$ 0.0001   &  0.005 $\pm$ 0.0001  \\
-+
+        mc   &  0.085 $\pm$ 0.0001   &  0.030 $\pm$ 0.0001   &  0.014 $\pm$ 0.0000   &  0.008 $\pm$ 0.0000   &  0.005 $\pm$ 0.0000  \\
-+
+   data/mc   &     1.02 $\pm$ 0.00   &     1.06 $\pm$ 0.00   &     1.06 $\pm$ 0.01   &     1.03 $\pm$ 0.01   &     1.02 $\pm$ 0.01  \\
-+
+\hline
-+
+\hline
-+
+ e + $\geq$1 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.099 $\pm$ 0.0008   &  0.038 $\pm$ 0.0005   &  0.019 $\pm$ 0.0004   &  0.011 $\pm$ 0.0003   &  0.008 $\pm$ 0.0002  \\
-+
+        mc   &  0.100 $\pm$ 0.0004   &  0.038 $\pm$ 0.0003   &  0.019 $\pm$ 0.0002   &  0.012 $\pm$ 0.0002   &  0.008 $\pm$ 0.0001  \\
-+
+   data/mc   &     0.99 $\pm$ 0.01   &     1.00 $\pm$ 0.02   &     0.99 $\pm$ 0.02   &     0.98 $\pm$ 0.03   &     0.97 $\pm$ 0.03  \\
-+
+\hline
-+
+\hline
-+
+ $\mu$ + $\geq$1 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.100 $\pm$ 0.0006   &  0.041 $\pm$ 0.0004   &  0.022 $\pm$ 0.0003   &  0.014 $\pm$ 0.0002   &  0.010 $\pm$ 0.0002  \\
-+
+        mc   &  0.099 $\pm$ 0.0004   &  0.039 $\pm$ 0.0002   &  0.020 $\pm$ 0.0002   &  0.013 $\pm$ 0.0001   &  0.009 $\pm$ 0.0001  \\
-+
+   data/mc   &     1.01 $\pm$ 0.01   &     1.05 $\pm$ 0.01   &     1.05 $\pm$ 0.02   &     1.06 $\pm$ 0.02   &     1.06 $\pm$ 0.03  \\
-+
+\hline
-+
+\hline
-+
+ e + $\geq$2 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.105 $\pm$ 0.0020   &  0.042 $\pm$ 0.0013   &  0.021 $\pm$ 0.0009   &  0.013 $\pm$ 0.0007   &  0.009 $\pm$ 0.0006  \\
-+
+        mc   &  0.109 $\pm$ 0.0011   &  0.043 $\pm$ 0.0007   &  0.021 $\pm$ 0.0005   &  0.013 $\pm$ 0.0004   &  0.009 $\pm$ 0.0003  \\
-+
+   data/mc   &     0.96 $\pm$ 0.02   &     0.97 $\pm$ 0.03   &     1.00 $\pm$ 0.05   &     1.01 $\pm$ 0.06   &     0.97 $\pm$ 0.08  \\
-+
+\hline
-+
+\hline
-+
+ $\mu$ + $\geq$2 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.106 $\pm$ 0.0016   &  0.045 $\pm$ 0.0011   &  0.025 $\pm$ 0.0008   &  0.016 $\pm$ 0.0007   &  0.012 $\pm$ 0.0006  \\
-+
+        mc   &  0.108 $\pm$ 0.0009   &  0.044 $\pm$ 0.0006   &  0.024 $\pm$ 0.0004   &  0.016 $\pm$ 0.0004   &  0.011 $\pm$ 0.0003  \\
-+
+   data/mc   &     0.98 $\pm$ 0.02   &     1.04 $\pm$ 0.03   &     1.04 $\pm$ 0.04   &     1.04 $\pm$ 0.05   &     1.06 $\pm$ 0.06  \\
-+
+\hline
-+
+\hline
-+
+ e + $\geq$3 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.117 $\pm$ 0.0055   &  0.051 $\pm$ 0.0038   &  0.029 $\pm$ 0.0029   &  0.018 $\pm$ 0.0023   &  0.012 $\pm$ 0.0019  \\
-+
+        mc   &  0.120 $\pm$ 0.0031   &  0.052 $\pm$ 0.0021   &  0.027 $\pm$ 0.0015   &  0.018 $\pm$ 0.0012   &  0.013 $\pm$ 0.0011  \\
-+
+   data/mc   &     0.97 $\pm$ 0.05   &     0.99 $\pm$ 0.08   &     1.10 $\pm$ 0.13   &     1.03 $\pm$ 0.15   &     0.91 $\pm$ 0.16  \\
-+
+\hline
-+
+\hline
-+
+ $\mu$ + $\geq$3 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.111 $\pm$ 0.0044   &  0.050 $\pm$ 0.0030   &  0.029 $\pm$ 0.0024   &  0.019 $\pm$ 0.0019   &  0.014 $\pm$ 0.0017  \\
-+
+        mc   &  0.115 $\pm$ 0.0025   &  0.051 $\pm$ 0.0017   &  0.030 $\pm$ 0.0013   &  0.020 $\pm$ 0.0011   &  0.015 $\pm$ 0.0009  \\
-+
+   data/mc   &     0.97 $\pm$ 0.04   &     0.97 $\pm$ 0.07   &     0.95 $\pm$ 0.09   &     0.97 $\pm$ 0.11   &     0.99 $\pm$ 0.13  \\
-+
+\hline
-+
+\hline
-+
+ e + $\geq$4 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.113 $\pm$ 0.0148   &  0.048 $\pm$ 0.0100   &  0.033 $\pm$ 0.0083   &  0.020 $\pm$ 0.0065   &  0.017 $\pm$ 0.0062  \\
-+
+        mc   &  0.146 $\pm$ 0.0092   &  0.064 $\pm$ 0.0064   &  0.034 $\pm$ 0.0048   &  0.024 $\pm$ 0.0040   &  0.021 $\pm$ 0.0037  \\
-+
+   data/mc   &     0.78 $\pm$ 0.11   &     0.74 $\pm$ 0.17   &     0.96 $\pm$ 0.28   &     0.82 $\pm$ 0.30   &     0.85 $\pm$ 0.34  \\
-+
+\hline
-+
+\hline
-+
+ $\mu$ + $\geq$4 jets            &           $>$ 1 GeV   &           $>$ 2 GeV   &           $>$ 3 GeV   &           $>$ 4 GeV   &           $>$ 5 GeV  \\
-+
+\hline
-+
+      data   &  0.130 $\pm$ 0.0128   &  0.052 $\pm$ 0.0085   &  0.028 $\pm$ 0.0063   &  0.019 $\pm$ 0.0052   &  0.019 $\pm$ 0.0052  \\
-+
+        mc   &  0.105 $\pm$ 0.0064   &  0.045 $\pm$ 0.0043   &  0.027 $\pm$ 0.0034   &  0.019 $\pm$ 0.0028   &  0.014 $\pm$ 0.0024  \\
-+
+   data/mc   &     1.23 $\pm$ 0.14   &     1.18 $\pm$ 0.22   &     1.03 $\pm$ 0.27   &     1.01 $\pm$ 0.32   &     1.37 $\pm$ 0.45  \\
-+
+\hline
-+
+\hline
-+
-+
+\end{tabular}
-+
+\end{center}
-+
+\end{table}
-+
-+
-+
-+
+%Figure.~\ref{fig:reliso} compares the relative track isolation
-+
+%for events with a track with $\pt > 10~\GeV$ in addition to a selected
-+
+%muon for $\Z+4$ jet events and various \ttll\ components. The
-+
+%isolation distributions show significant differences, particularly
-+
+%between the leptons from a \W\ or \Z\ decay and the tracks arising
-+
+%from $\tau$ decays. As can also be seen in the figure, the \pt\
-+
+%distribution for the various categories of tracks is different, where
-+
+%the decay products from $\tau$s are significantly softer. Since the
-+
+%\pt\ enters the denominator of the isolation definition and hence
-+
+%alters the isolation variable...
-+
-+
+%\begin{figure}[hbt]
-+
+%  \begin{center}
-+
+%       \includegraphics[width=0.5\linewidth]{plots/pfiso_njets4_log.png}%
-+
+%       \includegraphics[width=0.5\linewidth]{plots/pfpt_njets4.png}
-+
+%       \caption{
-+
+%         \label{fig:reliso}%\protect
-+
+%          Comparison of relative track isolation variable for PF cand probe in Z+jets and ttbar
-+
+%          Z+Jets and ttbar dilepton have similar isolation distributions
-+
+%          ttbar with leptonic and single prong taus tend to be less
-+
+%          isolated. The difference in the isolation can be attributed
-+
+%          to the different \pt\ distribution of the samples, since
-+
+%          $\tau$ decay products tend to be softer than leptons arising
-+
+%          from \W\ or \Z\ decays.}
-+
+%      \end{center}
-+
+%\end{figure}
-+
-+
+%       \includegraphics[width=0.5\linewidth]{plots/pfabsiso_njets4_log.png}
-+
-+
-+
+%BEGIN SECTION TO WRITE OUT
-+
+%In detail, the procedure to correct the dilepton background is:
-+
-+
+%\begin{itemize}
-+
+%\item Using tag-and-probe studies, we plot the distribution of {\bf absolute} track isolation for identified probe electrons
-+
+%and muons {\bf TODO: need to compare the e vs. $\mu$ track iso distributions, they might differ due to e$\to$e$\gamma$}.
-+
+%\item We verify that the distribution of absolute track isolation does not depend on the \pt\ of the probe lepton.
-+
+%This is due to the fact that this isolation is from ambient PU and jet activity in the event, which is uncorrelated with
-+
+%the lepton \pt {\bf TODO: verify this in data and MC.}.
-+
+%\item Our requirement is {\bf relative} track isolation $<$ 0.1. For a given \ttll\ MC event, we determine the \pt of the 2nd
-+
+%lepton and translate this to find the corresponding requirement on the {\bf absolute} track isolation, which is simply $0.1\times$\pt.
-+
+%\item We measure the efficiency to satisfy this requirement in data and MC, and define a scale-factor $SF_{\epsilon(trk)}$ which
-+
+%is the ratio of the data-to-MC efficiencies. This scale-factor is applied to the \ttll\ MC event.
-+
+%\item {\bf THING 2 we are unsure about: we can measure this SF for electrons and for muons, but we can't measure it for hadronic
-+
+%tracks from $\tau$ decays. Verena has showed that the absolute track isolation distribution in hadronic $\tau$ tracks is harder due
-+
+%to $\pi^0\to\gamma\gamma$ with $\gamma\to e^+e^-$.}
-+
+%\end{itemize}
-+
+%END SECTION TO WRITE OUT
-+
-+
-+
+{\bf fix me: What you have written in the next paragraph does not explain how $\epsilon_{fake}$ is measured.
-+
+Why not measure $\epsilon_{fake}$ in the b-veto region?}
-+
-+
+%A measurement of the $\epsilon_{fake}$ in data is non-trivial. However, it is
-+
+%possible to correct for differences in the $\epsilon_{fake}$ between data and MC by
-+
+%applying an additional scale factor for the single lepton background
-+
+%alone, using the sample in the \mt\ peak region. This scale factor is determined after applying the isolated track
-+
+%veto and after subtracting the \ttll\ component, corrected for the
-+
+%isolation efficiency derived previously.
-+
+%As shown in Figure~\ref{fig:vetoeffcomp}, the efficiency for selecting an
-+
+%isolated track in single lepton events is independent of \mt\, so the use of
-+
+%an overall scale factor is justified to estimate the contribution in
-+
+%the \mt\ tail.
-+
+%
-+
+%\begin{figure}[hbt]
-+
+%  \begin{center}
-+
+%       \includegraphics[width=0.5\linewidth]{plots/vetoeff_comp.png}
-+
+%       \caption{
-+
+%         \label{fig:vetoeffcomp}%\protect
-+
+%          Efficiency for selecting an isolated track comparing
-+
+%          single lepton \ttlj\ and dilepton \ttll\ events in MC and
-+
+%          data as a function of \mt. The
-+
+%          efficiencies in \ttlj\ and \ttll\ exhibit no dependence on
-+
+%          \mt\, while the data ranges between the two. This behavior
-+
+%          is expected since the low \mt\ region is predominantly \ttlj, while the
-+
+%          high \mt\ region contains mostly \ttll\ events.}
-+
+%      \end{center}
-+
+%\end{figure}
-+

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Comparing UserCode/benhoob/cmsnotes/StopSearch/systematics.tex (file contents): Revision 1.2 by vimartin, Fri Jun 29 02:57:07 2012 UTC vs. Revision 1.5 by vimartin, Wed Oct 3 05:48:26 2012 UTC

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Comparing UserCode/benhoob/cmsnotes/StopSearch/systematics.tex (file contents):
Revision 1.2 by vimartin, Fri Jun 29 02:57:07 2012 UTC vs.
Revision 1.5 by vimartin, Wed Oct 3 05:48:26 2012 UTC