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# Content
1 %\clearpage
2 \section{Background Estimation Techniques}
3 \label{sec:bkg}
4
5 In this section we describe the techniques used to estimate the SM backgrounds in our signal regions defined by requirements of large \MET.
6 The SM backgrounds fall into three categories:
7
8 \begin{itemize}
9 \item \zjets: this is the dominant background after the preselection. The \MET\ in \zjets\ events is estimated with the
10 ``\MET\ templates'' technique described in Sec.~\ref{sec:bkg_zjets};
11 \item Flavor-symmetric (FS) backgrounds: this category includes processes which produces 2 leptons of uncorrelated flavor. It is dominated
12 by \ttbar\ but also contains Z$\to\tau\tau$, WW, and single top processes. This is the dominant contribution in the signal regions, and it
13 is estimated using a data control sample of e$\mu$ events as described in Sec.~\ref{sec:bkg_fs};
14 \item WZ and ZZ backgrounds: this background is estimated from MC, after validating the MC modeling of these processes using data control
15 samples with jets and exactly 3 leptons (WZ control sample) and exactly 4 leptons (ZZ control sample) as described in Sec.~\ref{sec:bkg_vz};
16 %\item Rare SM backgrounds: this background contains rare processes such as $t\bar{t}$V and triple vector boson processes VVV (V=W,Z).
17 %This background is estimated from MC as described in Sec.~\ref{sec:bkg_raresm}. {\bf FIXME: add rare MC}
18 \end{itemize}
19
20 \subsection{Estimating the \zjets\ Background with \MET\ Templates}
21 \label{sec:bkg_zjets}
22
23 The premise of this data driven technique is that \MET\ in \zjets\ events
24 is produced by the hadronic recoil system and {\it not} by the leptons making up the Z.
25 Therefore, the basic idea of the \MET\ template method is to measure the \MET\ distribution in
26 a control sample which has no true MET and the same general attributes regarding
27 fake MET as in \zjets\ events. We thus use a sample of \gjets\ events, since both \zjets\
28 and \gjets\ events consist of a well-measured object recoiling against hadronic jets.
29
30 For selecting photon-like objects, the very loose photon selection described in Sec.~\ref{sec:phosel} is used.
31 It is not essential for the photon sample to have high purity. For our purposes, selecting jets with predominantly
32 electromagnetic energy deposition in a good fiducial volume suffices to ensure that
33 they are well measured and do not contribute to fake \MET. The \gjets\ events are selected with a suite of
34 single photon triggers with \pt thresholds varying from 22--90 GeV. The events are weighted by the trigger prescale
35 such that \gjets\ events evenly sample the conditions over the full period of data taking.
36 There remains a small difference in the PU conditions in the \gjets\ vs. \zjets\ samples due to the different
37 dependencies of the $\gamma$ vs. Z isolation efficiencies on PU. To account for this, we reweight the \gjets\ samples
38 to match the distribution of reconstructed primary vertices in the \zjets\ sample.
39
40 To account for kinematic differences between the hadronic systems in the control vs. signal
41 samples, we measure the \MET\ distributions in the \gjets\ sample in bins of the number of jets
42 and the scalar sum of jet transverse energies (\Ht). These \MET\ templates are extracted separately from the 5 single photon
43 triggers with thresholds 22, 36, 50, 75, and 90 GeV, so that the templates are effectively binned in photon \pt.
44 All \MET distributions are normalized to unit area to form ``MET templates''.
45 The prediction of the MET in each \Z event is the template which corresponds to the \njets,
46 \Ht, and Z \pt in the \zjets\ event. The prediction for the \Z sample is simply the sum of all such templates.
47 All templates are displayed in App.~\ref{app:templates}.
48
49 After preselection, there is a small contribution from backgrounds other than \zjets. To correct for this, the \MET\ templates
50 prediction is scaled such that the total background prediction matches the observed data yield in the \MET\ 0--60 GeV region.
51 Because the non-\zjets impurity in the low \MET\ region after preselection is very small, this results in
52 scaling factors of 0.985 (0.995) for the inclusive (targeted) search.
53
54 \subsection{Estimating the Flavor-Symmetric Background with e$\mu$ Events}
55 \label{sec:bkg_fs}
56
57 In this subsection we describe the background estimate for the FS background. Since this background produces equal rates of same-flavor (SF)
58 ee and $\mu\mu$ lepton pairs as opposite-flavor (OF) e$\mu$ lepton pairs, the OF yield can be used to estimate the SF yield, after
59 correcting for the different electron vs. muon offline selection efficiencies and the different efficiencies for the ee, $\mu\mu$, and e$\mu$ triggers.
60
61 An important quantity needed to translate from the OF yield to a prediction for the background in the SF final state is the ratio
62 $R_{\mu e} = \epsilon_\mu / \epsilon_e$, where $\epsilon_\mu$ ($\epsilon_e$) indicates the offline muon (electron) selection efficiency.
63 This quantity can be extracted from data using the observed Z$\to\mu\mu$ and Z$\to$ee yields in the preselection region, after correcting
64 for the different trigger efficiencies.
65
66 Hence we define:
67
68 \begin{itemize}
69 \item $N_{ee}^{\rm{trig}} = \epsilon_{ee}^{\rm{trig}}N_{ee}^{\rm{offline}}$,
70 \item $N_{\mu\mu}^{\rm{trig}} = \epsilon_{\mu\mu}^{\rm{trig}}N_{\mu\mu}^{\rm{offline}}$,
71 \item $N_{e\mu}^{\rm{trig}} = \epsilon_{e\mu}^{\rm{trig}}N_{e\mu}^{\rm{offline}}$.
72 \end{itemize}
73
74 Here $N_{\ell\ell}^{\rm{trig}}$ denotes the number of selected Z events in the $\ell\ell$ channel passing the offline and trigger selection
75 (in other words, the number of recorded and selected events), $\epsilon_{\ell\ell}^{\rm{trig}}$ is the trigger efficiency, and
76 $N_{\ell\ell}^{\rm{offline}}$ is the number of events that would have passed the offline selection if the trigger had an efficiency of 100\%.
77 Thus we calculate the quantity:
78
79 \begin{equation}
80 R_{\mu e} = \sqrt{\frac{N_{\mu\mu}^{\rm{offline}}}{N_{ee}^{\rm{offline}}}} = \sqrt{\frac{N_{\mu\mu}^{\rm{trig}}/\epsilon_{\mu\mu}^{\rm{trig}}}{N_{ee}^{\rm{trig}}/\epsilon_{ee}^{\rm{trig}}}}
81 = \sqrt{\frac{304953/0.88}{239661/0.95}} = 1.17\pm0.07.
82 \end{equation}
83
84 Here we have used the Z$\to\mu\mu$ and Z$\to$ee yields from Table~\ref{table:zyields_2j} and the trigger efficiencies quoted in Sec.~\ref{sec:datasets}.
85 The indicated uncertainty is due to the 3\% uncertainties in the trigger efficiencies. %{\bf FIXME: check for variation w.r.t. lepton \pt}.
86 The predicted yields in the ee and $\mu\mu$ final states are calculated from the observed e$\mu$ yield as
87
88 \begin{itemize}
89 \item $N_{ee}^{\rm{predicted}} = \frac {N_{e\mu}^{\rm{trig}}} {\epsilon_{e\mu}^{\rm{trig}}} \frac {\epsilon_{ee}^{\rm{trig}}} {2 R_{\mu e}}
90 = \frac{N_{e\mu}^{\rm{trig}}}{0.92}\frac{0.95}{2\times1.17} = (0.44\pm0.05) \times N_{e\mu}^{\rm{trig}}$ ,
91 \item $N_{\mu\mu}^{\rm{predicted}} = \frac {N_{e\mu}^{\rm{trig}}} {\epsilon_{e\mu}^{\rm{trig}}} \frac {\epsilon_{\mu\mu}^{\rm{trig}} R_{\mu e}} {2}
92 = \frac {N_{e\mu}^{\rm{trig}}} {0.95} \frac {0.88 \times 1.17}{2} = (0.54\pm0.07) \times N_{e\mu}^{\rm{trig}}$,
93 \end{itemize}
94
95 and the predicted yield in the combined ee and $\mu\mu$ channel is simply the sum of these two predictions:
96
97 \begin{itemize}
98 \item $N_{ee+\mu\mu}^{\rm{predicted}} = (0.98\pm0.06)\times N_{e\mu}^{\rm{trig}}$.
99 \end{itemize}
100
101 Note that the relative uncertainty in the combined ee and $\mu\mu$ prediction is smaller than those for the individual ee and $\mu\mu$ predictions
102 because the uncertainty in $R_{\mu e}$ cancels when summing the ee and $\mu\mu$ predictions. %{\bf N.B. these uncertainties are preliminary}.
103
104 To improve the statistical precision of the FS background estimate, we remove the requirement that the e$\mu$ lepton pair falls in the Z mass window.
105 Instead we scale the e$\mu$ yield by $K$, the efficiency for e$\mu$ events to satisfy the Z mass requirement, extracted from simulation. In Fig.~\ref{fig:K_incl}
106 we display the value of $K$ in data and simulation, for a variety of \MET\ requirements, for the inclusive analysis.
107 Based on this we chose $K=0.14\pm0.02$ for the lower \MET\ regions, $K=0.14\pm0.04$ for the \MET\ $>$ 200 GeV region,and $K=0.14\pm0.09$ for \MET\ $>$ 300 GeV,
108 where the larger uncertainties reflect the reduced statistical precision at large \MET.
109 The corresponding plot for the targeted analysis, including the b-veto, is displayed in Fig.~\ref{fig:K_targeted}.
110 Based on this we chose $K=0.13\pm0.02$
111 for all \MET\ regions up to \MET\ $>$ 150 GeV. For the \MET\ $>$ 200 GeV region we choose $K=0.13\pm0.05$, due to the reduced statistical precision.
112
113 \begin{figure}[!ht]
114 \begin{center}
115 \begin{tabular}{cc}
116 \includegraphics[width=0.4\textwidth]{plots/extractK_inclusive_19fb.pdf} &
117 \includegraphics[width=0.4\textwidth]{plots/extractK_exclusive_19fb.pdf} \\
118 \end{tabular}
119 \caption{\label{fig:K_incl}
120 The efficiency for e$\mu$ events to satisfy the dilepton mass requirement, $K$, in data and simulation for inclusive \MET\ intervals (left) and
121 exclusive \MET\ intervals (right) for the inclusive analysis.
122 }
123
124 \begin{comment}
125
126 ----------------------------------------
127 EXCLUSIVE RESULTS
128 ----------------------------------------
129
130 Using selection : ((((leptype==2)&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(isdata==0 || (run<197556 || run>198913)))&&(njets>=2))&&(lep1.pt()>20 && lep2.pt()>20)
131 Using weight : vtxweight * weight
132 OF entries (total) 44537
133 OF entries (Z mass) 6051
134 K 0.135865
135 Warning in <TROOT::Append>: Replacing existing TH1: htot (Potential memory leak).
136 Warning in <TROOT::Append>: Replacing existing TH1: hZ (Potential memory leak).
137
138 --------------------------------------------------------------
139 pfmet>0 && pfmet<30
140
141 data :
142 total : 7563
143 Z : 957
144 K : 0.13 +/- 0.004
145
146 MC :
147 total : 399.019
148 Z : 51.0493
149 K : 0.13 +/- 0.007
150 --------------------------------------------------------------
151
152
153 --------------------------------------------------------------
154 pfmet>30 && pfmet<60
155
156 data :
157 total : 14185
158 Z : 1893
159 K : 0.13 +/- 0.003
160
161 MC :
162 total : 755.309
163 Z : 111.206
164 K : 0.15 +/- 0.003
165 --------------------------------------------------------------
166
167
168 --------------------------------------------------------------
169 pfmet>60 && pfmet<100
170
171 data :
172 total : 14928
173 Z : 2122
174 K : 0.14 +/- 0.003
175
176 MC :
177 total : 838.418
178 Z : 123.554
179 K : 0.15 +/- 0.003
180 --------------------------------------------------------------
181
182
183 --------------------------------------------------------------
184 pfmet>100 && pfmet<200
185
186 data :
187 total : 7437
188 Z : 1029
189 K : 0.14 +/- 0.004
190
191 MC :
192 total : 451.624
193 Z : 67.7098
194 K : 0.15 +/- 0.004
195 --------------------------------------------------------------
196
197
198 --------------------------------------------------------------
199 pfmet>200 && pfmet<300
200
201 data :
202 total : 371
203 Z : 44
204 K : 0.12 +/- 0.018
205
206 MC :
207 total : 24.2441
208 Z : 2.67077
209 K : 0.11 +/- 0.013
210 --------------------------------------------------------------
211
212
213 --------------------------------------------------------------
214 pfmet>300
215
216 data :
217 total : 53
218 Z : 6
219 K : 0.11 +/- 0.046
220
221 MC :
222 total : 4.53108
223 Z : 0.230071
224 K : 0.05 +/- 0.022
225 --------------------------------------------------------------
226
227
228 ----------------------------------------
229 INCLUSIVE RESULTS
230 ----------------------------------------
231
232 Using selection : ((((leptype==2)&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(isdata==0 || (run<197556 || run>198913)))&&(njets>=2))&&(lep1.pt()>20 && lep2.pt()>20)
233 Using weight : vtxweight * weight
234 OF entries (total) 44537
235 OF entries (Z mass) 6051
236 K 0.135865
237 Warning in <TROOT::Append>: Replacing existing TH1: htot (Potential memory leak).
238 Warning in <TROOT::Append>: Replacing existing TH1: hZ (Potential memory leak).
239
240 --------------------------------------------------------------
241 pfmet>0
242
243 data :
244 total : 44537
245 Z : 6051
246 K : 0.14 +/- 0.002
247
248 MC :
249 total : 2472.89
250 Z : 356.434
251 K : 0.14 +/- 0.002
252 --------------------------------------------------------------
253
254
255 --------------------------------------------------------------
256 pfmet>30
257
258 data :
259 total : 36974
260 Z : 5094
261 K : 0.14 +/- 0.002
262
263 MC :
264 total : 2074.05
265 Z : 305.382
266 K : 0.15 +/- 0.002
267 --------------------------------------------------------------
268
269
270 --------------------------------------------------------------
271 pfmet>60
272
273 data :
274 total : 22789
275 Z : 3201
276 K : 0.14 +/- 0.002
277
278 MC :
279 total : 1318.79
280 Z : 194.166
281 K : 0.15 +/- 0.002
282 --------------------------------------------------------------
283
284
285 --------------------------------------------------------------
286 pfmet>100
287
288 data :
289 total : 7861
290 Z : 1079
291 K : 0.14 +/- 0.004
292
293 MC :
294 total : 480.402
295 Z : 70.6107
296 K : 0.15 +/- 0.004
297 --------------------------------------------------------------
298
299
300 --------------------------------------------------------------
301 pfmet>200
302
303 data :
304 total : 424
305 Z : 50
306 K : 0.12 +/- 0.017
307
308 MC :
309 total : 28.7751
310 Z : 2.90084
311 K : 0.10 +/- 0.012
312 --------------------------------------------------------------
313
314
315 --------------------------------------------------------------
316 pfmet>300
317
318 data :
319 total : 53
320 Z : 6
321 K : 0.11 +/- 0.046
322
323 MC :
324 total : 4.53108
325 Z : 0.230071
326 K : 0.05 +/- 0.022
327 --------------------------------------------------------------
328
329 \end{comment}
330
331 \end{center}
332 \end{figure}
333
334 \begin{figure}[!hb]
335 \begin{center}
336 \begin{tabular}{cc}
337 \includegraphics[width=0.4\textwidth]{plots/extractK_inclusive_bveto_19fb.pdf} &
338 \includegraphics[width=0.4\textwidth]{plots/extractK_exclusive_bveto_19fb.pdf} \\
339 \end{tabular}
340 \caption{
341 The efficiency for e$\mu$ events to satisfy the dilepton mass requirement, $K$, in data and simulation for inclusive \MET\ intervals (left) and
342 exclusive \MET\ intervals (right) for the targeted analysis, including the b-veto.
343 Based on this we chose $K=0.13\pm0.02$ for the \MET\ regions up to \MET\ $>$ 100 GeV.
344 For higher \MET\ regions we chose $K=0.13\pm0.07$.
345 %{\bf FIXME plots made with 10\% of \zjets\ MC statistics, to be remade with full statistics}
346 \label{fig:K_targeted}
347 }
348 \begin{comment}
349
350 Using selection : (((((leptype==2)&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(isdata==0 || (run<197556 || run>198913)))&&(njets>=2))&&(lep1.pt()>20 && lep2.pt()>20))&&(nbcsvm==0)
351 Using weight : vtxweight * weight
352 OF entries (total) 12006
353 OF entries (Z mass) 1407
354 K 0.117191
355 Warning in <TROOT::Append>: Replacing existing TH1: htot (Potential memory leak).
356 Warning in <TROOT::Append>: Replacing existing TH1: hZ (Potential memory leak).
357
358 --------------------------------------------------------------
359 pfmet>0 && pfmet<30
360
361 data :
362 total : 2719
363 Z : 273
364 K : 0.10 +/- 0.006
365
366 MC :
367 total : 131.974
368 Z : 15.1946
369 K : 0.12 +/- 0.020
370 --------------------------------------------------------------
371
372
373 --------------------------------------------------------------
374 pfmet>30 && pfmet<60
375
376 data :
377 total : 3842
378 Z : 435
379 K : 0.11 +/- 0.005
380
381 MC :
382 total : 172.956
383 Z : 21.9369
384 K : 0.13 +/- 0.007
385 --------------------------------------------------------------
386
387
388 --------------------------------------------------------------
389 pfmet>60 && pfmet<80
390
391 data :
392 total : 2029
393 Z : 269
394 K : 0.13 +/- 0.008
395
396 MC :
397 total : 109.789
398 Z : 13.9792
399 K : 0.13 +/- 0.008
400 --------------------------------------------------------------
401
402
403 --------------------------------------------------------------
404 pfmet>80 && pfmet<100
405
406 data :
407 total : 1490
408 Z : 194
409 K : 0.13 +/- 0.009
410
411 MC :
412 total : 73.3643
413 Z : 11.5154
414 K : 0.16 +/- 0.010
415 --------------------------------------------------------------
416
417
418 --------------------------------------------------------------
419 pfmet>100 && pfmet<150
420
421 data :
422 total : 1467
423 Z : 189
424 K : 0.13 +/- 0.009
425
426 MC :
427 total : 86.7947
428 Z : 11.742
429 K : 0.14 +/- 0.009
430 --------------------------------------------------------------
431
432
433 --------------------------------------------------------------
434 pfmet>150 && pfmet<200
435
436 data :
437 total : 320
438 Z : 31
439 K : 0.10 +/- 0.017
440
441 MC :
442 total : 19.4473
443 Z : 2.97965
444 K : 0.15 +/- 0.017
445 --------------------------------------------------------------
446
447
448 --------------------------------------------------------------
449 pfmet>200
450
451 data :
452 total : 139
453 Z : 16
454 K : 0.12 +/- 0.029
455
456 MC :
457 total : 8.99801
458 Z : 0.794136
459 K : 0.09 +/- 0.021
460 --------------------------------------------------------------
461
462 Warning in <TROOT::Append>: Replacing existing TH1: hdummy (Potential memory leak).
463 Info in <TCanvas::Print>: pdf file ../plots/extractK_exclusive_bveto.pdf has been created
464 root [3] extractK(false,true,true)
465 Using selection : (((((leptype==2)&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(isdata==0 || (run<197556 || run>198913)))&&(njets>=2))&&(lep1.pt()>20 && lep2.pt()>20))&&(nbcsvm==0)
466 Using weight : vtxweight * weight
467 OF entries (total) 12006
468 OF entries (Z mass) 1407
469 K 0.117191
470 Warning in <TROOT::Append>: Replacing existing TH1: htot (Potential memory leak).
471 Warning in <TROOT::Append>: Replacing existing TH1: hZ (Potential memory leak).
472
473 --------------------------------------------------------------
474 pfmet>0
475
476 data :
477 total : 12006
478 Z : 1407
479 K : 0.12 +/- 0.003
480
481 MC :
482 total : 603.333
483 Z : 78.1422
484 K : 0.13 +/- 0.005
485 --------------------------------------------------------------
486
487
488 --------------------------------------------------------------
489 pfmet>30
490
491 data :
492 total : 9287
493 Z : 1134
494 K : 0.12 +/- 0.004
495
496 MC :
497 total : 471.396
498 Z : 62.9476
499 K : 0.13 +/- 0.004
500 --------------------------------------------------------------
501
502
503 --------------------------------------------------------------
504 pfmet>60
505
506 data :
507 total : 5445
508 Z : 699
509 K : 0.13 +/- 0.005
510
511 MC :
512 total : 298.41
513 Z : 41.0107
514 K : 0.14 +/- 0.005
515 --------------------------------------------------------------
516
517
518 --------------------------------------------------------------
519 pfmet>80
520
521 data :
522 total : 3416
523 Z : 430
524 K : 0.13 +/- 0.006
525
526 MC :
527 total : 188.602
528 Z : 27.0313
529 K : 0.14 +/- 0.006
530 --------------------------------------------------------------
531
532
533 --------------------------------------------------------------
534 pfmet>100
535
536 data :
537 total : 1926
538 Z : 236
539 K : 0.12 +/- 0.008
540
541 MC :
542 total : 115.24
543 Z : 15.5158
544 K : 0.13 +/- 0.008
545 --------------------------------------------------------------
546
547
548 --------------------------------------------------------------
549 pfmet>150
550
551 data :
552 total : 459
553 Z : 47
554 K : 0.10 +/- 0.015
555
556 MC :
557 total : 28.4454
558 Z : 3.77378
559 K : 0.13 +/- 0.014
560 --------------------------------------------------------------
561
562
563 --------------------------------------------------------------
564 pfmet>200
565
566 data :
567 total : 139
568 Z : 16
569 K : 0.12 +/- 0.029
570
571 MC :
572 total : 8.99801
573 Z : 0.794136
574 K : 0.09 +/- 0.021
575 --------------------------------------------------------------
576
577 \end{comment}
578
579 \end{center}
580 \end{figure}
581
582
583 \begin{comment}
584
585 \begin{figure}[!hb]
586 \begin{center}
587 \begin{tabular}{cc}
588 \includegraphics[width=0.4\textwidth]{plots/extractK_inclusive_bvetoLoose_92fb.pdf} &
589 \includegraphics[width=0.4\textwidth]{plots/extractK_exclusive_bvetoLoose_92fb.pdf} \\
590 \end{tabular}
591 \caption{
592 The efficiency for e$\mu$ events to satisfy the dilepton mass requirement, $K$, in data and simulation for inclusive \MET\ intervals (left) and
593 exclusive \MET\ intervals (right) for the targeted analysis, including the b-veto.
594 %{\bf FIXME plots made with 10\% of \zjets\ MC statistics, to be remade with full statistics}
595 \label{fig:K_targeted}}
596
597
598 root [2] extractK(true,false,true)
599 Using selection : (((((leptype==2)&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(isdata==0 || (run<197556 || run>198913)))&&(njets>=2))&&(lep1.pt()>20 && lep2.pt()>20))&&(nbcsvl==0)
600 Using weight : vtxweight * weight
601 OF entries (total) 2715
602 OF entries (Z mass) 279
603 K 0.102762
604 Warning in <TStreamerInfo::Compile>: Counter fNClusterRange should not be skipped from class TTree
605 Info in <TCanvas::MakeDefCanvas>: created default TCanvas with name c1
606
607 --------------------------------------------------------------
608 pfmet>0 && pfmet<30
609
610 data :
611 total : 713
612 Z : 59
613 K : 0.08 +/- 0.011
614
615 MC :
616 total : 74.2549
617 Z : 7.09789
618 K : 0.10 +/- 0.025
619 --------------------------------------------------------------
620
621
622 --------------------------------------------------------------
623 pfmet>30 && pfmet<60
624
625 data :
626 total : 850
627 Z : 79
628 K : 0.09 +/- 0.010
629
630 MC :
631 total : 84.6973
632 Z : 9.55105
633 K : 0.11 +/- 0.009
634 --------------------------------------------------------------
635
636
637 --------------------------------------------------------------
638 pfmet>60 && pfmet<80
639
640 data :
641 total : 469
642 Z : 61
643 K : 0.13 +/- 0.017
644
645 MC :
646 total : 50.1496
647 Z : 5.92081
648 K : 0.12 +/- 0.012
649 --------------------------------------------------------------
650
651
652 --------------------------------------------------------------
653 pfmet>80 && pfmet<100
654
655 data :
656 total : 269
657 Z : 33
658 K : 0.12 +/- 0.021
659
660 MC :
661 total : 30.0547
662 Z : 4.67993
663 K : 0.16 +/- 0.014
664 --------------------------------------------------------------
665
666
667 --------------------------------------------------------------
668 pfmet>100 && pfmet<150
669
670 data :
671 total : 311
672 Z : 34
673 K : 0.11 +/- 0.019
674
675 MC :
676 total : 39.4475
677 Z : 5.02593
678 K : 0.13 +/- 0.014
679 --------------------------------------------------------------
680
681
682 --------------------------------------------------------------
683 pfmet>150 && pfmet<200
684
685 data :
686 total : 79
687 Z : 10
688 K : 0.13 +/- 0.040
689
690 MC :
691 total : 9.96228
692 Z : 1.4975
693 K : 0.15 +/- 0.023
694 --------------------------------------------------------------
695
696
697 --------------------------------------------------------------
698 pfmet>200
699
700 data :
701 total : 24
702 Z : 3
703 K : 0.12 +/- 0.072
704
705 MC :
706 total : 5.3503
707 Z : 0.425719
708 K : 0.08 +/- 0.027
709 --------------------------------------------------------------
710
711 root [3] Info in <TCanvas::Print>: pdf file /Users/benhoob/tas/ZMet2012/plots/extractK_exclusive_bvetoLoose_92fb.pdf has been created
712
713 root [3]
714 root [3] extractK(false,false,true)
715 Using selection : (((((leptype==2)&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(isdata==0 || (run<197556 || run>198913)))&&(njets>=2))&&(lep1.pt()>20 && lep2.pt()>20))&&(nbcsvl==0)
716 Using weight : vtxweight * weight
717 OF entries (total) 2715
718 OF entries (Z mass) 279
719 K 0.102762
720 Warning in <TROOT::Append>: Replacing existing TH1: htot (Potential memory leak).
721 Warning in <TROOT::Append>: Replacing existing TH1: hZ (Potential memory leak).
722
723 --------------------------------------------------------------
724 pfmet>0
725
726 data :
727 total : 2715
728 Z : 279
729 K : 0.10 +/- 0.006
730
731 MC :
732 total : 293.912
733 Z : 34.199
734 K : 0.12 +/- 0.008
735 --------------------------------------------------------------
736
737
738 --------------------------------------------------------------
739 pfmet>30
740
741 data :
742 total : 2002
743 Z : 220
744 K : 0.11 +/- 0.007
745
746 MC :
747 total : 219.661
748 Z : 27.101
749 K : 0.12 +/- 0.006
750 --------------------------------------------------------------
751
752
753 --------------------------------------------------------------
754 pfmet>60
755
756 data :
757 total : 1152
758 Z : 141
759 K : 0.12 +/- 0.010
760
761 MC :
762 total : 134.962
763 Z : 17.5498
764 K : 0.13 +/- 0.007
765 --------------------------------------------------------------
766
767
768 --------------------------------------------------------------
769 pfmet>80
770
771 data :
772 total : 683
773 Z : 80
774 K : 0.12 +/- 0.013
775
776 MC :
777 total : 84.8149
778 Z : 11.629
779 K : 0.14 +/- 0.009
780 --------------------------------------------------------------
781
782
783 --------------------------------------------------------------
784 pfmet>100
785
786 data :
787 total : 414
788 Z : 47
789 K : 0.11 +/- 0.017
790
791 MC :
792 total : 54.7604
793 Z : 6.94915
794 K : 0.13 +/- 0.011
795 --------------------------------------------------------------
796
797
798 --------------------------------------------------------------
799 pfmet>150
800
801 data :
802 total : 103
803 Z : 13
804 K : 0.13 +/- 0.035
805
806 MC :
807 total : 15.3125
808 Z : 1.92322
809 K : 0.13 +/- 0.019
810 --------------------------------------------------------------
811
812
813 --------------------------------------------------------------
814 pfmet>200
815
816 data :
817 total : 24
818 Z : 3
819 K : 0.12 +/- 0.072
820
821 MC :
822 total : 5.3503
823 Z : 0.425719
824 K : 0.08 +/- 0.027
825 --------------------------------------------------------------
826
827
828 \end{center}
829 \end{figure}
830
831
832 \end{comment}
833
834
835 \clearpage
836
837 \subsection{Estimating the WZ and ZZ Background with MC}
838 \label{sec:bkg_vz}
839
840 Backgrounds from W($\ell\nu$)Z($\ell\ell$) where the W lepton is not identified or is outside acceptance, and Z($\nu\nu$)Z($\ell\ell$),
841 are estimated from simulation. The MC modeling of these processes is validated by comparing the MC predictions with data in control samples
842 with exactly 3 leptons (WZ control sample) and exactly 4 leptons (ZZ control sample).
843 The critical samples are the WZJetsTo3LNu and ZZJetsTo4L, listed in Table~\ref{tab:mcsamples}
844 (the WZJetsTo2L2Q, ZZJetsTo2L2Q, and ZZJetsTo2L2Nu samples are also used in this analysis but their contribution to the 3-lepton and 4-lepton
845 control samples is negligible).
846
847 \subsubsection{WZ Validation Studies}
848 \label{sec:bkg_wz}
849
850 A pure WZ sample can be selected in data with the requirements:
851
852 \begin{itemize}
853 \item Exactly 3 $p_T>20$~GeV leptons passing analysis identication and isolation requirements,
854 \item 2 of the 3 leptons must fall in the Z window 81-101 GeV,
855 \item \MET $>$ 50 GeV (to suppress DY).
856 \end{itemize}
857
858 The data and MC yields passing the above selection are in Table~\ref{tab:wz}.
859 The inclusive yields (without any jet requirements) agree within 16\%, which is consistent within
860 the $\approx$15\% uncertainty in the theory prediction for the WZ cross section. A data vs. MC comparison of kinematic
861 distributions (jet multiplicity, \MET, Z \pt) is given in Fig.~\ref{fig:wz}. High \MET\
862 values in WZ and ZZ events arise from highly boosted W or Z bosons that decay leptonically,
863 and we therefore check that the MC does a reasonable job of reproducing the \pt distributions of the
864 leptonically decaying \Z. While the inclusive WZ yields are in reasonable agreement, we observe
865 an excess in data in events with at least 2 jets, corresponding to the jet multiplicity requirement
866 in our preselection. We observe 200 events in data while the MC predicts $130\pm3.1$~(stat), representing an excess of 53\%,
867 as indicated in Table~\ref{tab:wz2j}, and we therefore assess an uncertainty of 50\% on the WZ background.
868 %We note that the contributions from fake leptons and from \zjets\ with mismeasured \MET\
869 %is underestimated in the MC.
870 %This excess will be studied further. For the time being, based on these studies we currently assess an uncertainty of 50\% on the WZ yield.
871 %A data vs. MC comparison of several kinematic quantities in the sample with 3 leptons and at least 2 jets can be found in App.~\ref{app:WZ}.
872
873 \begin{comment}
874 We note some possible contributions to this discrepancy:
875
876 \begin{itemize}
877
878 \item {\bf The following checks refer to the 5.2 fb$^{-1}$ results and will be updated.}
879
880 \item The \zjets\ contribution is under-estimated here, for 2 reasons: first, because the \zjets\
881 yield passing a \MET $>$ 50 GeV requirement is under-estimated in MC and second, because the fake
882 rate is typically under-estimated in the MC. To get a rough idea for how much the excess depends
883 on the \zjets\ yield, if the \zjets\ yield is doubled then the excess is reduced from 78\% to 55\%.
884 Also note that we are currently using 10\% of the \zjets\ MC sample and there is 1 event with a weight
885 of about 5, so the plots and tables will be remade with full \zjets\ sample.
886
887 \item The \ttbar\ contribution is under-estimated here because the fake
888 rate is typically under-estimated in the MC. To get a rough idea for how much the excess depends
889 on the \ttbar\ yield, if the \ttbar\ yield is doubled then the excess is reduced from 78\% to 57\%.
890
891 \item Currently no attempt is made to reject jets from pile-up interactions, which may be responsible
892 for some of the excess at large \njets. To check this, we increase the jet \pt threhsold to 40 GeV, which
893 helps to suppress PU jets, and observe 39 events in data vs. an MC prediction of $25\pm5.2$~(stat),
894 decreasing the excess from 78\% to 58\%. In the future this may be improved by explicitly
895 requiring the jets to be consistent with originating from the signal primary vertex.
896
897 \end{itemize}
898 \end{comment}
899
900
901
902 \begin{table}[htb]
903 \begin{center}
904 \caption{\label{tab:wz} Data and Monte Carlo yields passing the WZ preselection. }
905 \begin{tabular}{lccccc}
906
907 %Loading babies at : ../output/V00-02-00
908 %Using selection : (((((((leptype==0 && (ee==1 || isdata==0))||(leptype==1 && (mm==1 || isdata==0)))||(leptype==2 && (em==1||me==1||isdata==0)))&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(lep1.pt()>20.0 && lep2.pt()>20.0))&&(nlep==3 && lep3.pt()>20.0))&&(pfmet>50))&&(dilmass>81 && dilmass<101)
909 %Using weight : weight * 19.3 * trgeff * vtxweight
910
911 \hline
912 \hline
913 Sample & ee & $\mu\mu$ & e$\mu$ & total \\
914 \hline
915 %SCALING ZJETS BY 111/946
916 WZ &244.9 $\pm$ 1.6 &317.9 $\pm$ 1.8 & 17.0 $\pm$ 0.4 &579.7 $\pm$ 2.4 \\
917 \zjets & 2.5 $\pm$ 2.0 & 6.4 $\pm$ 3.9 & 0.0 $\pm$ 0.0 & 8.9 $\pm$ 4.3 \\
918 ZZ & 5.3 $\pm$ 0.0 & 7.1 $\pm$ 0.1 & 0.4 $\pm$ 0.0 & 12.8 $\pm$ 0.1 \\
919 \ttbar & 2.5 $\pm$ 1.3 & 6.7 $\pm$ 2.0 & 7.5 $\pm$ 2.1 & 16.7 $\pm$ 3.2 \\
920 single top & 0.0 $\pm$ 0.0 & 0.5 $\pm$ 0.5 & 0.0 $\pm$ 0.0 & 0.5 $\pm$ 0.5 \\
921 WW & 0.0 $\pm$ 0.0 & 0.1 $\pm$ 0.1 & 0.2 $\pm$ 0.1 & 0.3 $\pm$ 0.1 \\
922 ttV & 8.6 $\pm$ 0.4 & 10.3 $\pm$ 0.4 & 2.5 $\pm$ 0.2 & 21.5 $\pm$ 0.7 \\
923 VVV & 3.4 $\pm$ 0.1 & 4.3 $\pm$ 0.1 & 0.6 $\pm$ 0.1 & 8.3 $\pm$ 0.2 \\
924 \hline
925 tot SM MC &267.1 $\pm$ 2.9 &353.3 $\pm$ 4.7 & 28.2 $\pm$ 2.2 &648.6 $\pm$ 6.0 \\
926 \hline
927 data & 312 & 391 & 50 & 753 \\
928 \hline
929 \hline
930
931 \end{tabular}
932 \end{center}
933 \end{table}
934
935 \begin{table}[htb]
936 \begin{center}
937 \caption{\label{tab:wz2j} Data and Monte Carlo yields passing the WZ preselection and \njets\ $\geq$ 2. }
938 \begin{tabular}{lccccc}
939
940 %Loading babies at : ../output/V00-02-00
941 %-------------------------------------
942 %USING SKIMMED SAMPLES WITH NJETS >= 2
943 %-------------------------------------
944
945 %Using selection : ((((((((leptype==0 && (ee==1 || isdata==0))||(leptype==1 && (mm==1 || isdata==0)))||(leptype==2 && (em==1||me==1||isdata==0)))&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(lep1.pt()>20.0 && lep2.pt()>20.0))&&(nlep==3 && lep3.pt()>20.0))&&(pfmet>50))&&(dilmass>81 && dilmass<101))&&(njets>=2)
946 %Using weight : weight * 19.3 * trgeff * vtxweight
947
948 \hline
949 \hline
950 Sample & ee & $\mu\mu$ & e$\mu$ & total \\
951 \hline
952 %SCALING ZJETS BY 111/946
953 \ttbar & 1.6 $\pm$ 0.9 & 3.4 $\pm$ 1.5 & 1.8 $\pm$ 1.1 & 6.9 $\pm$ 2.0 \\
954 \zjets & 1.9 $\pm$ 1.9 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 1.9 $\pm$ 1.9 \\
955 WZ & 40.0 $\pm$ 0.7 & 51.5 $\pm$ 0.7 & 2.7 $\pm$ 0.2 & 94.3 $\pm$ 1.0 \\
956 ZZ & 1.0 $\pm$ 0.0 & 1.4 $\pm$ 0.0 & 0.1 $\pm$ 0.0 & 2.6 $\pm$ 0.0 \\
957 single top & 0.0 $\pm$ 0.0 & 0.5 $\pm$ 0.5 & 0.0 $\pm$ 0.0 & 0.5 $\pm$ 0.5 \\
958 WW & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 \\
959 ttV & 8.0 $\pm$ 0.4 & 9.5 $\pm$ 0.4 & 2.2 $\pm$ 0.2 & 19.6 $\pm$ 0.6 \\
960 VVV & 1.9 $\pm$ 0.1 & 2.6 $\pm$ 0.1 & 0.2 $\pm$ 0.0 & 4.6 $\pm$ 0.2 \\
961 \hline
962 tot SM MC & 54.4 $\pm$ 2.2 & 69.0 $\pm$ 1.8 & 6.9 $\pm$ 1.1 &130.4 $\pm$ 3.1 \\
963 \hline
964 data & 87 & 91 & 22 & 200 \\
965 \hline
966 \hline
967
968 \end{tabular}
969 \end{center}
970 \end{table}
971
972 \begin{figure}[tbh]
973 \begin{center}
974 \includegraphics[width=1\linewidth]{plots/WZ_19fb.pdf}
975 \caption{\label{fig:wz}\protect
976 Data vs. MC comparisons for the WZ selection discussed in the text for \lumi.
977 The number of jets, missing transverse energy, and Z boson transverse momentum are displayed.
978 }
979 \begin{comment}
980 Loading babies at : ../output/V00-02-00
981 Using selection : (((((((leptype==0 && (ee==1 || isdata==0))||(leptype==1 && (mm==1 || isdata==0)))||(leptype==2 && (em==1||me==1||isdata==0)))&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(lep1.pt()>20.0 && lep2.pt()>20.0))&&(nlep==3 && lep3.pt()>20.0))&&(pfmet>50))&&(dilmass>81 && dilmass<101)
982 Using weight : weight * 19.3 * trgeff * vtxweight
983 Plotting var njets flavor sf
984 compareDataMC : apply trigeff 1
985 MC yield VVV 7.73
986 MC yield ttV 18.95
987 MC yield single top 0.51
988 MC yield WW 0.09
989 MC yield ZZ 12.38
990 MC yield WZ 562.71
991 MC yield ttbar 9.18
992 SCALING ZJETS BY 111/946
993 MC yield zjets 8.85
994 MC total yield 620.39
995 data yield 703
996 Plotting var pfmet flavor sf
997 compareDataMC : apply trigeff 1
998 MC yield VVV 7.73
999 MC yield ttV 18.95
1000 MC yield single top 0.51
1001 MC yield WW 0.09
1002 MC yield ZZ 12.38
1003 MC yield WZ 562.72
1004 MC yield ttbar 9.18
1005 SCALING ZJETS BY 111/946
1006 MC yield zjets 8.85
1007 MC total yield 620.40
1008 data yield 703
1009 Plotting var dileppt flavor sf
1010 compareDataMC : apply trigeff 1
1011 MC yield VVV 7.73
1012 MC yield ttV 18.95
1013 MC yield single top 0.51
1014 MC yield WW 0.09
1015 MC yield ZZ 12.38
1016 MC yield WZ 562.71
1017 MC yield ttbar 9.18
1018 SCALING ZJETS BY 111/946
1019 MC yield zjets 8.85
1020 MC total yield 620.38
1021 data yield 703
1022 \end{comment}
1023
1024 \end{center}
1025 \end{figure}
1026
1027 \clearpage
1028
1029 \subsubsection{ZZ Validation Studies}
1030 \label{sec:bkg_zz}
1031
1032 A pure ZZ sample can be selected in data with the requirements:
1033
1034 \begin{itemize}
1035 \item Exactly 4 $p_T>20$~GeV leptons passing analysis identication and isolation requirements,
1036 \item 2 of the 4 leptons must fall in the $Z$ window 81-101 GeV.
1037 \end{itemize}
1038
1039 The data and MC yields passing the above selection are in Table~\ref{tab:zz}.
1040 In this ZZ-dominated sample we observe good agreement between the data yield and the MC prediction.
1041 After requiring 2 jets (corresponding to the requirement in the analysis selection), we observe 14 events
1042 in data and the MC predicts $13.2\pm0.2$ events. Due to the limited statistical precision we assign an uncertainty
1043 of 50\% on the ZZ yield.
1044
1045 \begin{table}[htb]
1046 \begin{center}
1047 \caption{\label{tab:zz} Data and Monte Carlo yields for the ZZ preselection. }
1048 \begin{tabular}{lccccc}
1049
1050 %Loading babies at : ../output/V00-02-00
1051 %Using selection : ((((((leptype==0 && (ee==1 || isdata==0))||(leptype==1 && (mm==1 || isdata==0)))||(leptype==2 && (em==1||me==1||isdata==0)))&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(lep1.pt()>20.0 && lep2.pt()>20.0))&&(nlep==4 && lep3.pt()>20.0 && lep4.pt()>20.0))&&(dilmass>81 && dilmass<101)
1052 %Using weight : weight * 19.3 * trgeff * vtxweight
1053
1054 \hline
1055 \hline
1056 Sample & ee & $\mu\mu$ & e$\mu$ & total \\
1057 \hline
1058 %SCALING ZZ BY 1.92
1059 ZZ & 52.7 $\pm$ 0.2 & 73.3 $\pm$ 0.2 & 3.4 $\pm$ 0.0 &129.4 $\pm$ 0.3 \\
1060 WZ & 0.1 $\pm$ 0.0 & 0.1 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.3 $\pm$ 0.1 \\
1061 %SCALING ZJETS BY 111/946
1062 \zjets & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 \\
1063 \ttbar & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 \\
1064 WW & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 \\
1065 single top & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 & 0.0 $\pm$ 0.0 \\
1066 ttV & 1.3 $\pm$ 0.2 & 1.4 $\pm$ 0.2 & 0.3 $\pm$ 0.1 & 3.0 $\pm$ 0.2 \\
1067 VVV & 0.6 $\pm$ 0.1 & 0.8 $\pm$ 0.1 & 0.0 $\pm$ 0.0 & 1.4 $\pm$ 0.1 \\
1068 \hline
1069 tot SM MC & 54.7 $\pm$ 0.3 & 75.6 $\pm$ 0.3 & 3.8 $\pm$ 0.1 &134.1 $\pm$ 0.4 \\
1070 \hline
1071 data & 56 & 80 & 5 & 141 \\
1072 \hline
1073 \hline
1074
1075 \end{tabular}
1076 \end{center}
1077 \end{table}
1078
1079 \begin{figure}[tbh]
1080 \begin{center}
1081 \includegraphics[width=1\linewidth]{plots/ZZ_19fb.pdf}
1082 \caption{\label{fig:zz}\protect
1083 Data vs. MC comparisons for the ZZ selection discussed in the text for \lumi.
1084 The number of jets, missing transverse energy, and Z boson transverse momentum are displayed.
1085 }
1086 \end{center}
1087 \end{figure}
1088
1089 \begin{comment}
1090 Loading babies at : ../output/V00-02-00
1091 Using selection : ((((((leptype==0 && (ee==1 || isdata==0))||(leptype==1 && (mm==1 || isdata==0)))||(leptype==2 && (em==1||me==1||isdata==0)))&&(csc==0 && hbhe==1 && hcallaser==1 && ecaltp==1 && trkfail==1 && eebadsc==1 && hbhenew==1))&&(lep1.pt()>20.0 && lep2.pt()>20.0))&&(nlep==4 && lep3.pt()>20.0 && lep4.pt()>20.0))&&(dilmass>81 && dilmass<101)
1092 Using weight : weight * 19.3 * trgeff * vtxweight
1093 Plotting var njets flavor sf
1094 compareDataMC : apply trigeff 1
1095
1096 MC yield VVV 1.40
1097 MC yield ttV 2.64
1098 MC yield single top 0.00
1099 MC yield WW 0.00
1100 MC yield ttbar 0.00
1101 SCALING ZJETS BY 111/946
1102 MC yield zjets 0.00
1103 MC yield WZ 0.27
1104 SCALING ZJETS BY 1.92
1105 MC yield ZZ 125.99
1106 MC total yield 130.31
1107 data yield 136
1108 Plotting var pfmet flavor sf
1109 compareDataMC : apply trigeff 1
1110 MC yield VVV 1.40
1111 MC yield ttV 2.64
1112 MC yield single top 0.00
1113 MC yield WW 0.00
1114 MC yield ttbar 0.00
1115 SCALING ZJETS BY 111/946
1116 MC yield zjets 0.00
1117 MC yield WZ 0.27
1118 SCALING ZJETS BY 1.92
1119 MC yield ZZ 126.00
1120 MC total yield 130.32
1121 data yield 136
1122 Plotting var dileppt flavor sf
1123 compareDataMC : apply trigeff 1
1124 MC yield VVV 1.40
1125 MC yield ttV 2.64
1126 MC yield single top 0.00
1127 MC yield WW 0.00
1128 MC yield ttbar 0.00
1129 SCALING ZJETS BY 111/946
1130 MC yield zjets 0.00
1131 MC yield WZ 0.27
1132 SCALING ZJETS BY 1.92
1133 MC yield ZZ 126.00
1134 MC total yield 130.33
1135 data yield 136
1136 \end{comment}
1137
1138
1139
1140 %\subsection{Estimating the Rare SM Backgrounds with MC}
1141 %\label{sec:bkg_raresm}
1142
1143 %{\bf TODO: list samples, yields in preselection region, and show \MET\ distribution}