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1   \section{Event reconstruction}
2   \label{sec:eventReconstruction}
3  
4 < \subsection{Trigger selection and efficiencies}
4 > We categorize \WZ\ three-lepton final state as following
5 > \begin{itemize}
6 > \item $3e$: for \WZ events with $\W \to e \nu$ and $\Z\to \epem$.
7 > \item $2e1\mu$: for \WZ events with $\W \to \mu \nu$ and $\Z\to \epem$.
8 > \item $2\mu 1e$: for \WZ events with $\W \to e \nu$ and $\Z\to \mumu$.
9 > \item $3\mu$: for \WZ events with $\W \to \mu \nu$ and $\Z\to \mumu$.
10 > \end{itemize}
11  
12  
13 < \subsection{Lepton identification}
13 > \subsection{Trigger selection and efficiencies}
14  
15 + Events stemming from the three-lepton final states of $\WZ$ production
16 + are collected by the electron and/or muon triggers. For each channel,
17 + a minimun number of HLT requirements is chosen while keeping
18 + the HLT efficiency for selected events close to 100\%. The same
19 + HLT requirements are used for channels with the same \Z decay mode:
20 + \begin{itemize}
21 + \item for $3e$ and $2e1\mu$: HLTSingleElectron or HLTDoubleElectronRelaxed
22 + \item for $2\mu1e$ and $3\mu$: HLTSingleMuonIso
23 + \end{itemize}
24 + The HLT efficiencies for all modes for events passing the full
25 + selection described in this section are given in table~\ref{tab:hlteff}.
26 +
27 + \begin{table}[tbph]
28 + \begin{center}
29 +
30 + \begin{tabular}{llc} \hline \hline
31 + Channel    &   HLT selection                                   & HLT efficiency \\ \hline
32 + $3e$       &   HLTSingleElectron or HLTDoubleElectronRelaxed   &  0.996         \\
33 + $2e1\mu$   &   HLTSingleElectron or HLTDoubleElectronRelaxed   &  0.969         \\
34 + $2\mu 1e$  &   HLTSingleMuonIso                                &  0.966         \\
35 + $3\mu$     &   HLTSingleMuonIso                                &  0.994         \\ \hline \hline
36 + \end{tabular}
37 +
38 + \end{center}
39 + \caption{HLT Efficiencies, in percent, for all
40 +  the events in the generated phase space that have been retained  by
41 +  the complete event selection.}
42 + \label{tab:hlteff}
43 + \end{table}
44 +
45 +
46 + \begin{figure}[tbp]
47 +  \begin{center}
48 +  \scalebox{0.7}{\includegraphics{figs/mu_isol.eps}}
49 +  \caption{Muon isolation variables for the muon associated
50 +    to the \W boson decay in $2e1\mu$ events: in the left plot
51 +    we illustrate the sum of calorimetric energy in a $\Delta R=0.3$ cone
52 +    around the muon candidate; in the right plot we display the sum of
53 +    transverse momenta of tracks within a $\Delta R = 0.25$ cone around
54 +    the muon candidate. The normalization of signal and background
55 +    distributions is arbitrary.
56 + }
57 +  \label{fig:mu_isol}
58 +  \end{center}
59 + \end{figure}
60 +
61 + \begin{figure}[tb]
62 +  \begin{center}
63 +  \scalebox{0.6}{\includegraphics{figs/mu_SIP.eps}}
64 +  \caption{
65 +    Muon impact parameter significance distribution
66 +    in $2e1\mu$ events. The normalization of signal and background
67 +    distributions is arbitrary.
68 +  }
69 +  \label{fig:mu_SIP}
70 +  \end{center}
71 + \end{figure}
72  
73  
74 < \subsection{\WZ candidate selection}
74 > \subsection{Lepton identification}
75 > \label{sec:leptonId}
76  
77 + The requirements used for electron identification in this analysis are described
78 + in~\cite{noteElectronID}.
79  
80 < \subsection{Signal extraction}
80 > Muon candidates are selected from global muons, which are reconstructed
81 > by combining measurements in the muon chambers and the central tracker.
82 > An additional isolation criterion is imposed to require the energy
83 > measured in the calorimeters within a $\Delta R = 0.3$ cone around the
84 > muon to be smaller than 3 GeV and the sum of the $p_T$ of tracks
85 > within a $\Delta R = 0.25$ cone around the muon must be smaller than 2 GeV.
86 > These cuts reduce the background from muons originated in
87 > \b-quark decays of the $\Zbbbar$ background, which are close to tracks
88 > and clusters from the other \b-quark decay products.
89 >
90 > %Figures~\ref{fig:muonisol} and ~\ref{fig:muonisoleffi} show the
91 > %performance of the isolation cut. The distribution of the isolation
92 > %variables for the $\Z\b\bbar(\epem\b\bbar)$ is particularly
93 > %interesting, since muons only stem from  \b-quark decays.
94 >
95 > The significance of the muon impact parameter in the plane
96 > transverse to the beam, $S_{IP}$, discriminates against leptons from
97 > heavy-quark decays in all standard model background processes. This
98 > variable is defined as the ratio between the measured impact parameter
99 > and its uncertainty: $S_{IP}=IP/\sigma_{IP}$, and is required to
100 > satisfy $S_{IP}<3$. This requirement is applied only for muon candidates
101 > and not for electrons. For electron candidates, a significant fraction of the
102 > background comes from misidentified light quark jets. Thus,
103 > the requirement on the impact parameter significance does not
104 > increase the significance of the $\W\to e$ channels, as can be seen in
105 > Fig.~\ref{fig:wl_IP_SvsCut}.
106 >
107 > \begin{figure}[p]
108 >  \begin{center}
109 >  \scalebox{0.6}{\includegraphics{figs/wl_IP_eff.eps}}
110 >  \caption{Efficiency for signal and background as a function
111 >    of the requirement on the \W-boson lepton impact parameter
112 >    significance. All other criteria but the one on impact parameter
113 >    significance are applied.
114 > %    Only events with 81.1 GeV $< M_Z < $ 101.1 \gev
115 > %    are considered.
116 >  }
117 >  \label{fig:wl_IP_eff}
118 >  \end{center}
119 > %\end{figure}
120 >
121 > %\begin{figure}[bt]
122 >  \begin{center}
123 >  \scalebox{0.6}{\includegraphics{figs/wl_IP_SvsCut.eps}}
124 >  \caption{Signal significance as a function of requirement on
125 >    the \W-boson lepton impact parameter significance. All other criteria but
126 >    the requirement on the impact parameter significance are applied.
127 > %    Only events with 81.1 GeV $< M_Z < $ 101.1 \gev are considered.
128 >  }
129 >  \label{fig:wl_IP_SvsCut}
130 >  \end{center}
131 > \end{figure}
132 >
133 >
134 > \begin{table}[tbp]
135 > \begin{tabular}{|l|c|c|c|c|} \hline
136 >              &  $3e$ & $2e1\mu$ & $2\mu 1e$ & $3\mu$ \\ \hline \hline
137 > \multicolumn{5}{|c|}{Lepton selection} \\ \hline
138 > Electrons     &   \multicolumn{3}{|c|}{{\tt SimpleLoose} requirements for \Z reconstruction} & \\
139 >              &   \multicolumn{3}{|c|}{{\tt SimpleTight} requirements for \W} &  \\ \hline
140 > Muons         &  &  \multicolumn{3}{|c|}{ Track Isolation:$ {\tt IsoTrack}(\Delta R= 0.25) < 2 \gev$}  \\
141 >              &  &  \multicolumn{3}{|c|}{ Calorimetric Isolation:$  {\tt IsoCalo}(\Delta R = 0.3)  < 5 \gev$}  \\
142 >              &  &  \multicolumn{3}{|c|}{$S_{IP}=IP/\sigma_{IP}<3$ }  \\ \hline
143 > HLT requirement & \multicolumn{2}{|c|}{ HLTSingleElectron or HLTDoubleElectronRelaxed}
144 >                & \multicolumn{2}{|c|}{  HLTSingleMuonIso} \\ \hline
145 > \multicolumn{5}{|c|}{\Z reconstruction} \\ \hline
146 > Lepton cuts   &  \multicolumn{4}{|c|}{for both \Z leptons: $p_T > 15$ GeV} \\
147 > Mass window   &  \multicolumn{4}{|c|}{$50 \gev < M_Z < 120 \gev $ } \\
148 > Second \Z veto &  \multicolumn{4}{|c|}{No independent second \Z candidate with $50 \gev < M_Z < 120 \gev $ } \\ \hline
149 > \multicolumn{5}{|c|}{\W lepton selection} \\ \hline
150 >
151 > Other cuts    &     &        & $\Delta R(\mu_Z,e_W)>0.1$ &  \\ \hline
152 > Signal region  &    \multicolumn{4}{|c|}{$81 \gev < M_Z < 101 \gev $ } \\ \hline \hline
153 >
154 > \end{tabular}
155 > \caption{Summary of the criteria we use to select \WZ\ final state}
156 > \label{tab:allcuts}
157 > \end{table}
158 >
159 >
160 > \begin{figure}[p]
161 >  \begin{center}
162 >  \scalebox{0.6}{\includegraphics{figs/wlpt_cuteff.eps}}
163 >  \caption{Efficiency for signal and background as a function
164 >    of the cut value on the \W-boson lepton transverse momentum.
165 >    All other cuts but the cut on this variable are applied.
166 >    Only events with 81.1 GeV $< M_Z < $ 101.1 \gev
167 >    are considered.}
168 >  \label{fig:wlpt_cuteff}
169 >  \end{center}
170 > %\end{figure}
171 >
172 > %\begin{figure}[bt]
173 >  \begin{center}
174 >  \scalebox{0.6}{\includegraphics{figs/wlpt_cutS.eps}}
175 >  \caption{Signal significance as a function of the cut value on
176 >    the \W-boson lepton transverse momentum. All other cuts but
177 >    the cut on this variable are applied. Only events with
178 >    81.1 GeV $< M_Z < $ 101.1 \gev are considered.}
179 >  \label{fig:wlpt_cutS}
180 >  \end{center}
181 > \end{figure}
182  
183  
184 < \subsection{Systematic uncertainties}
184 > \subsection{\WZ candidate selection}
185  
186 + Events are accepted if they contain at least three charged leptons,
187 + either electrons or muons, with $p_T > 15\,\mathrm{GeV}$ and $| \eta | < 2.5$ for
188 + electrons,$| \eta | < 2.4$ for muons, as discussed in Section~\ref{sec:leptonId}.
189 +
190 + The \WZ candidate selection proceeds from building all possible
191 + \Z-boson candidates from same-flavour opposite-charge lepton pairs.
192 + For $\Z \to ee$ decays, electron candidates have to fulfill the loose requirements
193 + defined in~\cite{noteElectronID}.
194 +
195 + Events are retained if the mass of the \Z boson candidate is
196 + within 20 GeV of the \Z boson mass, $m_Z$. The event is
197 + rejected if a second \Z candidate is found. This second \Z boson candidate is formed
198 + using all possible same-flavour opposite-charge combinations which are left
199 + after removing the two leptons already used for the first \Z boson candidate. This
200 + secondary \Z boson veto helps to suppress $\Z\Z$ events.
201 + %The invariant
202 + %mass distribution for accepted \Z candidates is shown in
203 + %Figure~\ref{fig:zcandidates}.
204 +
205 + % and the \Z mass resolution is shown in
206 + %Figure~\ref{fig:dzmass}.
207 +
208 + After the \Z boson candidate is identified, the remaining leptons in the event
209 + are required to pass the tight criteria described in~\cite{noteElectronID}.
210 + If more than one lepton candidate satisfies the tight requirements, the one with the
211 + highest $p_T$ is associated with \W boson decay. This lepton's $p_T$ is effective
212 + discriminant against \Zbbbar and \Zjets production (see Fig.~\ref{fig:wlpt_cuteff}).
213 + We require the transverse momentum to exceed 20 GeV, as it maximizes
214 + the significance of the \WZ\ signal with respect to background as shown in
215 + Fig.~\ref{wlpt_cuteff}.
216 +
217 + An additional requirement on the isolation between electron and muon candidates is applied
218 + for the $2\mu 1e$ channel, by demanding the value of $\Delta R$ between the electron
219 + candidate associated with the \W boson decay and any of the two muons associated with
220 + the \Z boson decay to be greater than 0.1.
221 +
222 + This requirement allows suppressing the contribution of $\Z \to \mu\mu$
223 + decays, where one of the two muons radiates a photon which is reconstructed
224 + as an electron, possibly after conversion. This can be seen as a peak in the dimuon
225 + invariant mass at  around 60 GeV in Fig.~\ref{fig:Z2mu1e_60GeVPeak}.
226 +
227 + The summary of the selection criteria is given in Table~\ref{tab:allcuts}.
228 +
229 + The expected number of the events satisfying the sequential steps of the selection
230 + is listed in Tables~\ref{tab:sel-effA}.  
231 + In Table~\ref{tab:wz-effimatrix} we list the total selection efficiency for  different
232 + \W and \Z boson decay modes. It can be seen lepton candidates from \W and \Z
233 + boson decays are almost always are reconstructed with the correct flavor. As expected,
234 + there is a small contribution from $\W \to \tau \nu_\tau \to \ell \nu_\ell \nu_\tau$
235 + decays. However, this contribution is suppressed, mostly due to $p_T$ requirement
236 + on the third lepton, as leptons from $\tau$ decays are not as energetic as those from
237 + $\W \to \ell \nu$ processes.
238 +
239 + In Tables~ref\label{tab:wz-matcheffi-Zee} and \label{tab:wz-matcheffi-Zmumu} we
240 + display the fraction of reconstructed \WZ events with correctly-matched leptons.
241 + It can be seen that the lepton associated with the \W boson decay is correctly matched
242 + to the true Monte Carlo lepton from the \W boson decay in more than 90\% of
243 + the cases, even for events with several lepton candidates available to be associated
244 + to the \W boson decay. The choice to take the lepton candidate with the leading $p_T$ is,
245 + therefore, justified.
246 +
247 + \begin{table}[p]
248 +  \begin{center}
249 +
250 +
251 +
252 +
253 + \begin{tabular}{lcc|cc|cc|cc|c} \hline \hline
254 + \multicolumn{9}{c}{ {\bf $3e$ Channel}} \\ \hline  \hline
255 + Step                                 & \WZ  & $\epsilon$ & $b\bar{b}\ell\ell$  & $\epsilon$ & $\Z+jets$  & $\epsilon$ & $t\bar{t}+jets$  & $\epsilon$ \\ \hline
256 + All events                       & 546   &                    & 72,700 &                     & 1,268,000       &                       & 17,600     &               \\
257 + Found $\Z \to ee$         & 205   & 38\%         & 27,800 & 38\%            & 502,300          & 40\%            & 2,920        & 17\%    \\
258 + Found $\W \to e\nu$    & 42.0  & 21\%         & 171       & 0.6\%           & 309.6               & 0.06\%        & 13.8           & 0.5\%   \\
259 + \W lepton $p_T$ cut    & 34.9  & 83\%          & 23.7     & 14\%            & 86.8                  & 28 \%          &   8.3            & 60\%   \\
260 + Passes HLT                  & 34.7  & 100\%        & 23.6     & 99\%            & 86.8                  &100\%         &   8.3            & 100\%  \\
261 + \Z mass window           & 31.6  & 91\%          & 17.5     & 74\%            & 51.9                  &60\%           &    3.3            & 39\%    \\ \hline
262 + Overall efficiency        &           &  5.8\%        &              &   0.024\%    &                            & 0.0041\%  &                     & 0.019\% \\
263 + \hline\hline
264 +
265 + \multicolumn{9}{c}{ {\bf $2e1\mu$ Channel}} \\ \hline  \hline
266 + Step   & \WZ  & $\epsilon$ & $b\bar{b}\ell\ell$ & $\epsilon$ & $\Z+jets$  & $\epsilon$ & $t\bar{t}+jets$ & $\epsilon$  \\ \hline
267 + All events                        & 546  &             & 72,770 &                 & 1,268,000       &                    & 17,600            &             \\
268 + Found $\Z \to ee$          & 201  & 38\%  & 27,800  & 38\%      &  502,300          &  40\%     &     2,921          &17\% \\
269 + Found $\W \to \mu\nu$ & 47.9 & 23\%  & 748       & 2.7\%      &  2194         &  0.43\%  &      56.8          &1.9\% \\
270 + \W lepton $p_T$ cut      & 37.1 & 77\%  & 9.6        & 1.3\%      &   9.6                  &  0.4\%         &      17.5         &31\% \\
271 + Passes HLT                    & 36.2 & 98\%  & 9.3        & 96\%       &   8.3                  &  87\%    &     15.2   & 87 \%) \\
272 + \Z mass window             & 32.5 & 90\%  & 8.2        &  88\%      &    7.3                 &  88\%            &       4.9         & 32\%) \\ \hline
273 + Overall efficiency          &          & 6.0\% &               & 0.011\% &                           &  0.00058\% &                      &     0.028\% \\
274 + \hline \hline
275 +
276 + \multicolumn{9}{c}{ {\bf $2\mu1e$ Channel}} \\ \hline  \hline
277 + Step   & \WZ   & $\epsilon$ & $b\bar{b}\ell\ell$   & $\epsilon$ & $\Z+jets$   & $\epsilon$ & $t\bar{t}+jets$  & $\epsilon$ \\ \hline
278 + All events       & 546  &   & 72,770   &    & 1,268,000 &    & 17,600 &  \\
279 + Found $\Z \to \mu\mu$     & 234  &43\%&      31,890 & 44\% & 577,200 & 46\%   & 2779 & 16\% \\
280 + Found $\W \to e\nu$          & 48.8 &21\%&    214        & 0.67\%   & 702 & 0.12\%         & 15.1 & 0.54\% \\
281 + \W lepton $p_T$ cut          & 40.7 &83\%&      50.6      & 24\%      & 464.0 & 66\%      & 10.3 & 68\% \\
282 + $\Delta R(e,\mu)$ cut       & 40.6&100\%&      23.3     & 46\%     & 93.0 & 20\%         & 7.1 & 70\%  \\
283 + Passes HLT                       & 39.4 &97\%&        23.2     & 99\%      & 88.8 & 95\%        & 6.6  & 93\%  \\
284 + \Z mass window                & 35.6 & 90\% &          18.9 & 81\%      & 50.3 & 57\%       & 2.8   &44\%  \\ \hline
285 + Overall efficiency              &           &6.5\%  &                  & 0.026\% &           & 0.0040\%  &          & 0.016\% \\
286 + \hline \hline
287 +
288 + \multicolumn{9}{c}{ {\bf $3\mu$ Channel}} \\ \hline  \hline
289 + Step   & \WZ   & $\epsilon$ & ${b\bar{b}\ell\ell}$   & $\epsilon$ & $\Z+jets$   & $\epsilon$ & ${t\bar{t}+jets}$  & $\epsilon$ \\ \hline
290 + All events       & 546 &   & 72,770  &      & 1,268,000  &   & 17,600 &  \\
291 + Found $Z \to \mu\mu$        & 234     & 43\%   & 31,900 & 44\%       & 577,000 & 45\%          & 2779  & 16 \% \\
292 + Found $W \to \mu$             & 58        & 25 \%  & 811      & 2.5\%      & 2521       & 0.44\%       & 35.3   & 1.23 \% \\
293 + W Lepton Pt cut                   & 44.2    & 77 \% & 8.9         & 1.1\%      & 1.8          & 0.07\%        & 1.7     & 4.8 \% \\
294 + Passes HLT                         & 44.0    & 99\%  & 8.9          & 100\%    & 1.8         & 100 \%        & 1.7     & 100 \% \\
295 + Z mass window                   & 40.0    & 91 \%)  & 7.8        & 88\%      & 1.8          & 100 \%        & 1.2     & 69\% \\ \hline
296 + Overall efficiency               &             & 7.3 \% &                & 0.011\% &                & 0.00015\% &            & 0.0065\% \\
297 + \hline
298 + \end{tabular}
299 +
300 +
301 + \caption{Expected number of signal and background events passing the different
302 +  selections steps together with the efficiency of each requirement and total efficiency of
303 +  selection criteria in the \WZ, \Zbbbar, \Zjets and \ttjets samples for an integrated luminosity
304 +  of 1 \invfb.}
305 + \label{tab:sel-effA}
306 + \end{center}
307 + \end{table}
308 +
309 + \begin{table}[p]
310 + \begin{center}
311 + \begin{tabular}{l|ccccc}
312 + \hline \hline
313 +   & \multicolumn{5}{c}{$\Z \to ee$ and \W decay modes below} \\
314 + Reconstruction channel  &  $e \nu$
315 +   &  $\mu \nu $
316 +   &  $\tau \nu \to e \nu \nu  $
317 +   &  $\tau \nu \to \mu \nu \nu $
318 +   &  $\tau \nu \to {\rm hadrons~} \nu$
319 + \\ \hline
320 + $3e$       &  17.4 \%  &  0.0319 \%  &  6.42 \%  &  0 \%  &  0.162 \% \\
321 + $2e1\mu$   &  0 \%  &  18.6 \%  &  0 \%  &  5.53 \%  &  0.0485 \% \\
322 + $2\mu1e$   &  0 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
323 + $3\mu$     &  0 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
324 + \hline \hline
325 +
326 + & \multicolumn{5}{c}{$\Z \to \mu\mu$ and \W decay modes below} \\
327 + Reconstruction channel  &  $e\nu$
328 +   &  $\mu\nu$
329 +   &  $\tau\nu \to e\nu\nu$
330 +   &  $\tau\nu \to \mu\nu\nu$
331 +   &  $\tau\nu \to {\rm hadrons~}\nu$
332 + \\ \hline
333 + $3e$        &  0 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
334 + $2e1\mu$   &  0.0104 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
335 + $2\mu1e$   &  19.6 \%  &  0.0208 \%  &  5.56 \%  &  0 \%  &  0.18 \% \\
336 + $3\mu$     &  0 \%  &  23.4 \%  &  0.0573 \%  &  6.77 \%  &  0.0164 \% \\
337 + \hline \hline
338 + \end{tabular}
339 + \end{center}
340 + \caption{Selection efficiency for signal events in the four selection channels for the different
341 +  generated \W and \Z decay channels.}
342 + \label{tab:wz-effimatrix}
343 +
344 + %\end{table}
345 + %\begin{table}[tbp]
346 + \begin{center}
347 + \begin{tabular}{llcc} \hline
348 +  & & \multicolumn{2}{c}{Generated decay} \\
349 +  & & \multicolumn{2}{c}{$\Z \to ee $} \\
350 + Selection channel  &    &  $\W \to e\nu$   &  $\W \to \mu\nu$ \\
351 + \hline \hline
352 + \multicolumn{4}{c}{all} \\ \hline
353 + $3e$        & all & 1644 events         & 3 events    \\
354 + $3e$        & matched \Z & 93$\pm$1\% & 100\%\\
355 + $3e$        & matched \W & 92$\pm$1\% & 0\\
356 + $3e$        & matched \WZ & 91$\pm$1\% & 0\\
357 + \hline \hline
358 +
359 + \multicolumn{4}{c}{exactly 1 \W lepton candidate} \\ \hline
360 + $3e$        & all & 1602  events       & 0 events    \\
361 + $3e$        & matched \Z & 94$\pm$1\% & 0\\
362 + $3e$        & matched \W & 92$\pm$1\% & 0\\
363 + $3e$        & matched \WZ & 91$\pm$1\% & 0\\
364 + \hline \hline
365 +
366 + \multicolumn{4}{c}{more than 1 \W lepton candidate} \\ \hline
367 + $3e$        & all & 42 events  & 3 events   \\
368 + $3e$        & matched \Z & 93$\pm$4\% & 100\%\\
369 + $3e$        & matched \W & 91 $\pm$5\% & 0\\
370 + $3e$        & matched \WZ & 91$\pm$5\% & 0\\
371 + \hline \hline
372 +
373 + \multicolumn{4}{c}{all} \\ \hline
374 + $2e1\mu$   & all & 0  events   & 1746 events \\
375 + $2e1\mu$   & matched \Z & 0 & 100\%\\
376 + $2e1\mu$   & matched \W & 0 & 100\%\\
377 + $2e1\mu$   & matched \WZ & 0 & 100\%\\
378 + \hline \hline
379 +
380 + \multicolumn{4}{c}{exactly 1 \W lepton candidate} \\ \hline
381 + $2e1\mu$   & all & 0 events    & 1715 events \\
382 + $2e1\mu$   & matched \Z & 0 & 100\%\\
383 + $2e1\mu$   & matched \W & 0 & 100\%\\
384 + $2e1\mu$   & matched \WZ & 0 & 100\%\\
385 + \hline \hline
386 +
387 + \multicolumn{4}{c}{more than 1 \W lepton candidate} \\ \hline
388 + $2e1\mu$   & all & 0     & 31   \\
389 + $2e1\mu$   & matched \Z & 0 & 100\%\\
390 + $2e1\mu$   & matched \W & 0 & 100\%\\
391 + $2e1\mu$   & matched \WZ & 0 & 100\% \\ \hline \hline
392 + \end{tabular}
393 + \end{center}
394 + \caption{Fractions of events with correctly matched leptons
395 +  to true decay product of \W and \Z decays for final states
396 +  with generated $\Z\to ee$ decays}
397 + \label{tab:wz-matcheffi-Zee}
398 + \end{table}
399 +
400 +
401 +
402 + \begin{table}[tbp]
403 + \begin{center}
404 + \begin{tabular}{llcc} \hline
405 +  & & \multicolumn{2}{c}{Generated decay:} \\
406 + & & \multicolumn{2}{c}{$\Z \to \mu\mu $} \\
407 + Selection channel  &    &  $\W \to e\nu$   &  $\W \to \mu\nu$
408 + \\
409 + \hline \hline
410 + \multicolumn{4}{c}{all} \\ \hline
411 + $2\mu1e$   & all & 1895 events  & 2 events   \\
412 + $2\mu1e$   & matched \Z & 100\% & 100\%\\
413 + $2\mu1e$   & matched \W & 99$\pm$1\% & 0\\
414 + $2\mu1e$   & matched \WZ & 99$\pm$1\% & 0\\
415 + \hline \hline
416 +
417 + \multicolumn{4}{c}{exactly 1 \W lepton candidate} \\ \hline
418 + $2\mu1e$   & all & 1847 events & 0 events    \\
419 + $2\mu1e$   & matched \Z & 100\% & 0\\
420 + $2\mu1e$   & matched \W & 99$\pm$1\% & 0\\
421 + $2\mu1e$   & matched \WZ & 99$\pm$1\% & 0\\
422 + \hline \hline
423 +
424 + \multicolumn{4}{c}{more than 1 \W lepton candidate} \\ \hline
425 + $2\mu1e$   & all & 48 events   & 2 events    \\
426 + $2\mu1e$   & matched \Z & 100\% & 100\%\\
427 + $2\mu1e$   & matched \W & 94$\pm$3.5\%& 0\\
428 + $2\mu1e$   & matched \WZ & 94$\pm$3.5\% & 0\\
429 + \hline \hline
430 +
431 + \multicolumn{4}{c}{all} \\ \hline
432 + $3\mu$     & all & 0 events   & 2251 events \\
433 + $3\mu$     & matched \Z & 0 & 94$\pm$1\%\\
434 + $3\mu$     & matched \W & 0 & 93$\pm$1\%\\
435 + $3\mu$     & matched \WZ & 0 & 93$\pm$1\%\\
436 + \hline \hline
437 +
438 + \multicolumn{4}{c}{exactly 1 \W lepton candidate} \\ \hline
439 + $3\mu$     & all & 0 events    & 2207 events \\
440 + $3\mu$     & matched \Z & 0 & 94$\pm$1\%\\
441 + $3\mu$     & matched \W & 0 & 93$\pm$1\%\\
442 + $3\mu$     & matched \WZ & 0 & 93$\pm$1\%\\
443 + \hline \hline
444 +
445 + \multicolumn{4}{c}{more than 1 \W lepton candidate} \\ \hline
446 + $3\mu$     & all & 0 events    & 44 events  \\
447 + $3\mu$     & matched \Z & 0 & 91$\pm$4\%\\
448 + $3\mu$     & matched \W & 0 & 91$\pm$4\%\\
449 + $3\mu$     & matched \WZ & 0 & 91$\pm$4\%\\ \hline \hline
450 + \end{tabular}
451 + \end{center}
452 + \caption{Fractions of MC \WZ events with correctly matched leptons
453 +  to true decay product of \W and \Z decays for final states
454 +  with generated $\Z\to \mu\mu$ decays}
455 + \label{tab:wz-matcheffi-Zmumu}
456 + \end{table}
457 +
458 +
459 + %\subsection{Signal extraction}
460 + %\input D0Matrix
461 + \input zjetbackground
462 +
463 +
464 + \section{Systematic uncertainties}
465 + \input Sys
466 +
467 +
468 + \begin{figure}[bt]
469 +  \begin{center}
470 +  \scalebox{0.8}{\includegraphics{figs/met_by_channel.eps}}
471 +  \caption{Missing transverse mass for the four signal categories.
472 +    The distributions  show the number of expected events
473 +    for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 \gev
474 +    are shown. All selection cuts are applied.}
475 +  \label{fig:met}
476 +  \end{center}
477 + \end{figure}
478 +
479 + \begin{figure}[bt]
480 +  \begin{center}
481 +  \scalebox{0.8}{\includegraphics{figs/mtw_by_channel.eps}}
482 +  \caption{W transverse mass for the four signal categories.
483 +    The distributions  show the number of expected events
484 +    for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 GeV are shown.
485 +    All selection cuts are applied.}
486 +  \label{fig:mtw}
487 +  \end{center}
488 + \end{figure}
489  
490  
491  

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