57 |
|
An additional isolation criterion requires that the energy |
58 |
|
measured in the calorimeters within a $\Delta R = 0.3$ cone around the |
59 |
|
muon must be smaller than 3 GeV and the sum of the $p_t$ of tracks |
60 |
< |
within a $\Delta R = 0.25$ cone around the muon must be smaller than 2 |
61 |
< |
GeV. These cuts reduce the background from muons originated in |
60 |
> |
within a $\Delta R = 0.25$ cone around the muon must be smaller than 2 \gev. |
61 |
> |
These cuts reduce the background from muons originated in |
62 |
|
\b-quark decays of the $\Zbbbar$ background, which are close to tracks |
63 |
|
and clusters from the other \b-quark decay products. |
64 |
|
|
78 |
|
|
79 |
|
|
80 |
|
|
81 |
+ |
\begin{table}[tbp] |
82 |
+ |
\begin{tabular}{|l|c|c|c|c|} \hline |
83 |
+ |
& $3e$ & $2e1\mu$ & $2\mu 1e$ & $3\mu$ \\ \hline \hline |
84 |
+ |
\multicolumn{5}{|c|}{Lepton selection} \\ \hline |
85 |
+ |
Electrons & \multicolumn{3}{|c|}{{\tt SimpleLoose} requirements for Z reconstruction} & \\ |
86 |
+ |
& \multicolumn{3}{|c|}{{\tt SimpleTight} requirements for W} & \\ \hline |
87 |
+ |
Muons & & \multicolumn{3}{|c|}{ Track Isolation:$ {\tt IsoTrack}(\Delta R= 0.25) < 2 \gev$} \\ |
88 |
+ |
& & \multicolumn{3}{|c|}{ Calorimetric Isolation:$ {\tt IsoCalo}(\Delta R = 0.3) < 5 \gev$} \\ |
89 |
+ |
& & \multicolumn{3}{|c|}{$S_{IP}=IP/\sigma_{IP}<3$ } \\ \hline |
90 |
+ |
HLT requirement & \multicolumn{2}{|c|}{ HLTSingleElectron or HLTDoubleElectronRelaxed} |
91 |
+ |
& \multicolumn{2}{|c|}{ HLTSingleMuonIso} \\ \hline |
92 |
+ |
\multicolumn{5}{|c|}{Z reconstruction} \\ \hline |
93 |
+ |
Lepton cuts & \multicolumn{4}{|c|}{for both Z leptons: $p_t > 15 GeV$} \\ |
94 |
+ |
Mass window & \multicolumn{4}{|c|}{$50 \gev < M_Z < 120 \gev $ } \\ |
95 |
+ |
Second Z veto & \multicolumn{4}{|c|}{No independent second Z candidate with $50 \gev < M_Z < 120 \gev $ } \\ \hline |
96 |
+ |
\multicolumn{5}{|c|}{W lepton selection} \\ \hline |
97 |
+ |
|
98 |
+ |
Other cuts & & & $\Delta R(\mu_Z,e_W)>0.1$ & \\ \hline |
99 |
+ |
Signal region & \multicolumn{4}{|c|}{$81 \gev < M_Z < 101 \gev $ } \\ \hline \hline |
100 |
+ |
|
101 |
+ |
\end{tabular} |
102 |
+ |
\caption{Summary of all cuts used in the WZ selection} |
103 |
+ |
\label{tab:allcuts} |
104 |
+ |
\end{table} |
105 |
+ |
|
106 |
+ |
|
107 |
+ |
\begin{figure}[p] |
108 |
+ |
\begin{center} |
109 |
+ |
\scalebox{0.6}{\includegraphics{figs/wlpt_cuteff.eps}} |
110 |
+ |
\caption{Efficiency for signal and background as a function |
111 |
+ |
of the cut value on the \W-boson lepton transverse momentum. |
112 |
+ |
All other cuts but the cut on this variable are applied. |
113 |
+ |
Only events with 81.1 GeV $< M_Z < $ 101.1 \gev |
114 |
+ |
are considered.} |
115 |
+ |
\label{fig:wlpt_cuteff} |
116 |
+ |
\end{center} |
117 |
+ |
%\end{figure} |
118 |
+ |
|
119 |
+ |
%\begin{figure}[bt] |
120 |
+ |
\begin{center} |
121 |
+ |
\scalebox{0.6}{\includegraphics{figs/wlpt_cutS.eps}} |
122 |
+ |
\caption{Signal significance as a function of the cut value on |
123 |
+ |
the \W-boson lepton transverse momentum. All other cuts but |
124 |
+ |
the cut on this variable are applied. Only events with |
125 |
+ |
81.1 GeV $< M_Z < $ 101.1 \gev are considered.} |
126 |
+ |
\label{fig:wlpt_cutS} |
127 |
+ |
\end{center} |
128 |
+ |
\end{figure} |
129 |
+ |
|
130 |
+ |
|
131 |
|
\subsection{\WZ candidate selection} |
132 |
|
|
133 |
|
Events are accepted if they contain at least three charged leptons, |
161 |
|
the additional leptons are not considered further. |
162 |
|
The transverse momentum of this lepton is required to be larger |
163 |
|
than 20 GeV. This last requirement is effective in rejecting |
164 |
< |
the \Zbbbar and \Zjets backgrounds, and the cut value is chosen in |
164 |
> |
the \Zbbbar and \Zjets backgrounds, see Figure~\ref{fig:wlpt_cuteff}, |
165 |
> |
and the cut value is chosen in |
166 |
|
the range that maximises the significance as shown in |
167 |
< |
Figure~\ref{fig:s_vs_wlpt}. |
167 |
> |
Figure~\ref{fig:wlpt_cutS}. |
168 |
> |
|
169 |
> |
An additional requirement on the isolation between electron and muons is applied |
170 |
> |
for the $2\mu 1e$ channel, by demanding $\Delta R$ between the electron associated |
171 |
> |
to the \W-decay and any of the two muons associated to the \Z-decay be greater than |
172 |
> |
0.1. This requirement allows to suppress the contributions of $\Z \to \mu\mu$ |
173 |
> |
decays, where one of the two muons radiates a photon which is reconstructed |
174 |
> |
as electrons, possibly after conversion, which shows up as a peak at around 60 GeV |
175 |
> |
in the Z mass distribution, as shown in figure~\ref{fig:Z2mu1e_60GeVPeak}. |
176 |
> |
|
177 |
> |
The summary of the selection can be seen in Table~\ref{tab:allcuts}. |
178 |
|
|
179 |
|
The expected number of events passing the various steps of the selection |
180 |
|
is listed in Tables~\ref{tab:sel-effA} and~\ref{tab:sel-effB}. |
268 |
|
|
269 |
|
|
270 |
|
|
271 |
< |
\subsection{Signal extraction} |
211 |
< |
|
271 |
> |
%\subsection{Signal extraction} |
272 |
|
%\input D0Matrix |
273 |
|
\input zjetbackground |
274 |
|
|
275 |
|
|
276 |
< |
\subsection{Systematic uncertainties} |
276 |
> |
\section{Systematic uncertainties} |
277 |
|
\input Sys |
278 |
|
|
279 |
|
|
280 |
|
\begin{figure}[bt] |
281 |
|
\begin{center} |
282 |
+ |
\scalebox{0.8}{\includegraphics{figs/met_by_channel.eps}} |
283 |
+ |
\caption{Missing transverse mass for the four signal categories. |
284 |
+ |
The distributions show the number of expected events |
285 |
+ |
for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 \gev |
286 |
+ |
are shown. All selection cuts are applied.} |
287 |
+ |
\label{fig:met} |
288 |
+ |
\end{center} |
289 |
+ |
\end{figure} |
290 |
+ |
|
291 |
+ |
\begin{figure}[bt] |
292 |
+ |
\begin{center} |
293 |
|
\scalebox{0.8}{\includegraphics{figs/mtw_by_channel.eps}} |
294 |
|
\caption{W transverse mass for the four signal categories. |
295 |
|
The distributions show the number of expected events |
296 |
< |
for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 GeV are shown.} |
296 |
> |
for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 GeV are shown. |
297 |
> |
All selection cuts are applied.} |
298 |
|
\label{fig:mtw} |
299 |
|
\end{center} |
300 |
|
\end{figure} |
301 |
+ |
|
302 |
+ |
|
303 |
+ |
|
304 |
+ |
|
305 |
+ |
\begin{table}[tbp] |
306 |
+ |
\begin{center} |
307 |
+ |
\begin{tabular}{lccccc} |
308 |
+ |
\hline \hline |
309 |
+ |
& \multicolumn{5}{c}{$Z \to ee $} \\ |
310 |
+ |
& $W \to e$ |
311 |
+ |
& $W \to \mu$ |
312 |
+ |
& $W \to \tau \to e$ |
313 |
+ |
& $W \to \tau \to \mu$ |
314 |
+ |
& $W \to \tau \to hadrons$ |
315 |
+ |
\\ \hline |
316 |
+ |
$3e$ & 17.4 \% & 0.0319 \% & 6.42 \% & 0 \% & 0.162 \% \\ |
317 |
+ |
$2e1\mu$ & 0 \% & 18.6 \% & 0 \% & 5.53 \% & 0.0485 \% \\ |
318 |
+ |
$2\mu1e$ & 0 \% & 0 \% & 0 \% & 0 \% & 0 \% \\ |
319 |
+ |
$3\mu$ & 0 \% & 0 \% & 0 \% & 0 \% & 0 \% \\ |
320 |
+ |
\hline \hline |
321 |
+ |
& \multicolumn{5}{c}{$Z \to \mu\mu $} \\ |
322 |
+ |
& $W \to e$ |
323 |
+ |
& $W \to \mu$ |
324 |
+ |
& $W \to \tau \to e$ |
325 |
+ |
& $W \to \tau \to \mu$ |
326 |
+ |
& $W \to \tau \to hadrons$ |
327 |
+ |
\\ \hline |
328 |
+ |
$3e$ & 0 \% & 0 \% & 0 \% & 0 \% & 0 \% \\ |
329 |
+ |
$2e1\mu$ & 0.0104 \% & 0 \% & 0 \% & 0 \% & 0 \% \\ |
330 |
+ |
$2\mu1e$ & 19.6 \% & 0.0208 \% & 5.56 \% & 0 \% & 0.18 \% \\ |
331 |
+ |
$3\mu$ & 0 \% & 23.4 \% & 0.0573 \% & 6.77 \% & 0.0164 \% \\ |
332 |
+ |
\hline \hline |
333 |
+ |
\end{tabular} |
334 |
+ |
\end{center} |
335 |
+ |
\caption{Selection efficiency for signal events in the four selection channels for the different |
336 |
+ |
generated \W and \Z decay channels.} |
337 |
+ |
\label{tab:wz-effimatrix} |
338 |
+ |
\end{table} |
339 |
+ |
|
340 |
+ |
|
341 |
+ |
\begin{table}[tbp] |
342 |
+ |
\begin{center} |
343 |
+ |
\begin{tabular}{llcc} \hline |
344 |
+ |
& & \multicolumn{2}{c}{Generated decay:} \\ |
345 |
+ |
& & \multicolumn{2}{c}{$Z \to ee $} \\ |
346 |
+ |
Selection channel & & $W \to e$ & $W \to \mu$ \\ \hline |
347 |
+ |
\hline \hline |
348 |
+ |
\multicolumn{4}{c}{all} \\ \hline |
349 |
+ |
$3e$ & all & 1644 & 3 \\ |
350 |
+ |
$3e$ & matched Z & 0.937+/-0.00598 & 1+/-0\\ |
351 |
+ |
$3e$ & matched W & 0.915+/-0.00688 & 0+/--1\\ |
352 |
+ |
$3e$ & matched WZ & 0.914+/-0.00691 & 0+/--1\\ |
353 |
+ |
\hline \hline |
354 |
+ |
\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline |
355 |
+ |
$3e$ & all & 1602 & 0 \\ |
356 |
+ |
$3e$ & matched Z & 0.938+/-0.00604 & -1+/--1\\ |
357 |
+ |
$3e$ & matched W & 0.915+/-0.00696 & -1+/--1\\ |
358 |
+ |
$3e$ & matched WZ & 0.914+/-0.00699 & -1+/--1\\ |
359 |
+ |
\hline \hline |
360 |
+ |
\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline |
361 |
+ |
$3e$ & all & 42 & 3 \\ |
362 |
+ |
$3e$ & matched Z & 0.929+/-0.0397 & 1+/-0\\ |
363 |
+ |
$3e$ & matched W & 0.905+/-0.0453 & 0+/--1\\ |
364 |
+ |
$3e$ & matched WZ & 0.905+/-0.0453 & 0+/--1\\ |
365 |
+ |
\hline \hline |
366 |
+ |
\multicolumn{4}{c}{all} \\ \hline |
367 |
+ |
$2e1\mu$ & all & 0 & 1746 \\ |
368 |
+ |
$2e1\mu$ & matched Z & -1+/--1 & 0.999+/-0.000573\\ |
369 |
+ |
$2e1\mu$ & matched W & -1+/--1 & 1+/-0\\ |
370 |
+ |
$2e1\mu$ & matched WZ & -1+/--1 & 0.999+/-0.000573\\ |
371 |
+ |
\hline \hline |
372 |
+ |
\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline |
373 |
+ |
$2e1\mu$ & all & 0 & 1715 \\ |
374 |
+ |
$2e1\mu$ & matched Z & -1+/--1 & 0.999+/-0.000583\\ |
375 |
+ |
$2e1\mu$ & matched W & -1+/--1 & 1+/-0\\ |
376 |
+ |
$2e1\mu$ & matched WZ & -1+/--1 & 0.999+/-0.000583\\ |
377 |
+ |
\hline \hline |
378 |
+ |
\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline |
379 |
+ |
$2e1\mu$ & all & 0 & 31 \\ |
380 |
+ |
$2e1\mu$ & matched Z & -1+/--1 & 1+/-0\\ |
381 |
+ |
$2e1\mu$ & matched W & -1+/--1 & 1+/-0\\ |
382 |
+ |
$2e1\mu$ & matched WZ & -1+/--1 & 1+/-0\\ \hline \hline |
383 |
+ |
\end{tabular} |
384 |
+ |
\end{center} |
385 |
+ |
\caption{Fractions of events with correctly matched leptons |
386 |
+ |
to true decay product of \W and \Z decays for final states |
387 |
+ |
with generated $\Z\to ee$ decays} |
388 |
+ |
\label{tab:wz-matcheffi-Zee} |
389 |
+ |
\end{table} |
390 |
+ |
|
391 |
+ |
|
392 |
+ |
|
393 |
+ |
\begin{table}[tbp] |
394 |
+ |
\begin{center} |
395 |
+ |
\begin{tabular}{llcc} \hline |
396 |
+ |
& & \multicolumn{2}{c}{Generated decay:} \\ |
397 |
+ |
& & \multicolumn{2}{c}{$Z \to \mu\mu $} \\ |
398 |
+ |
Selection channel & & $W \to e$ & $W \to \mu$ |
399 |
+ |
\\ \hline |
400 |
+ |
\hline \hline |
401 |
+ |
\multicolumn{4}{c}{all} \\ \hline |
402 |
+ |
$2\mu1e$ & all & 1895 & 2 \\ |
403 |
+ |
$2\mu1e$ & matched Z & 1+/-0 & 1+/-0\\ |
404 |
+ |
$2\mu1e$ & matched W & 0.985+/-0.00282 & 0+/--1\\ |
405 |
+ |
$2\mu1e$ & matched WZ & 0.985+/-0.00282 & 0+/--1\\ |
406 |
+ |
\hline \hline |
407 |
+ |
\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline |
408 |
+ |
$2\mu1e$ & all & 1847 & 0 \\ |
409 |
+ |
$2\mu1e$ & matched Z & 1+/-0 & -1+/--1\\ |
410 |
+ |
$2\mu1e$ & matched W & 0.986+/-0.00274 & -1+/--1\\ |
411 |
+ |
$2\mu1e$ & matched WZ & 0.986+/-0.00274 & -1+/--1\\ |
412 |
+ |
\hline \hline |
413 |
+ |
\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline |
414 |
+ |
$2\mu1e$ & all & 48 & 2 \\ |
415 |
+ |
$2\mu1e$ & matched Z & 1+/-0 & 1+/-0\\ |
416 |
+ |
$2\mu1e$ & matched W & 0.938+/-0.0349 & 0+/--1\\ |
417 |
+ |
$2\mu1e$ & matched WZ & 0.938+/-0.0349 & 0+/--1\\ |
418 |
+ |
\hline \hline |
419 |
+ |
\multicolumn{4}{c}{all} \\ \hline |
420 |
+ |
$3\mu$ & all & 0 & 2251 \\ |
421 |
+ |
$3\mu$ & matched Z & -1+/--1 & 0.943+/-0.00488\\ |
422 |
+ |
$3\mu$ & matched W & -1+/--1 & 0.933+/-0.00526\\ |
423 |
+ |
$3\mu$ & matched WZ & -1+/--1 & 0.933+/-0.00526\\ |
424 |
+ |
\hline \hline |
425 |
+ |
\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline |
426 |
+ |
$3\mu$ & all & 0 & 2207 \\ |
427 |
+ |
$3\mu$ & matched Z & -1+/--1 & 0.944+/-0.0049\\ |
428 |
+ |
$3\mu$ & matched W & -1+/--1 & 0.934+/-0.00529\\ |
429 |
+ |
$3\mu$ & matched WZ & -1+/--1 & 0.934+/-0.00529\\ |
430 |
+ |
\hline \hline |
431 |
+ |
\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline |
432 |
+ |
$3\mu$ & all & 0 & 44 \\ |
433 |
+ |
$3\mu$ & matched Z & -1+/--1 & 0.909+/-0.0433\\ |
434 |
+ |
$3\mu$ & matched W & -1+/--1 & 0.909+/-0.0433\\ |
435 |
+ |
$3\mu$ & matched WZ & -1+/--1 & 0.909+/-0.0433\\ \hline \hline |
436 |
+ |
\end{tabular} |
437 |
+ |
\end{center} |
438 |
+ |
\caption{Fractions of MC \WZ events with correctly matched leptons |
439 |
+ |
to true decay product of \W and \Z decays for final states |
440 |
+ |
with generated $\Z\to \mu\mu$ decays} |
441 |
+ |
\label{tab:wz-matcheffi-Zmumu} |
442 |
+ |
\end{table} |
443 |
+ |
|