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root/cvsroot/UserCode/benhoob/cmsnotes/StopSearch/eventsel.tex
Revision: 1.13
Committed: Fri Oct 5 20:11:57 2012 UTC (12 years, 7 months ago) by vimartin
Content type: application/x-tex
Branch: MAIN
Changes since 1.12: +5 -5 lines
Log Message:
updating trigger SFs

File Contents

# User Rev Content
1 benhoob 1.1
2 fkw 1.5 This analysis uses several different control regions in addition to the signal regions.
3     All of these different regions are defined in this section.
4 vimartin 1.7 %Figure~\ref{fig:venndiagram} illustrates the relationship between these regions.
5 benhoob 1.1
6 vimartin 1.7 \subsection{Single Lepton Selection}
7    
8     [UPDATE SELECTION]
9 fkw 1.5
10 vimartin 1.10 The single lepton preselection sample is based on the following criteria, starting from the requirements described
11     on \url{https://twiki.cern.ch/twiki/bin/viewauth/CMS/SUSYstop#SINGLE_LEPTON_CHANNEL}
12 benhoob 1.1 \begin{itemize}
13 vimartin 1.2 \item satisfy the trigger requirement (see
14 claudioc 1.9 Table.~\ref{tab:DatasetsData}).
15     Note that the analysis triggers are inclusive single lepton triggers.
16     Dilepton triggers are used only for the dilepton control region.
17 vimartin 1.2 \item select events with one high \pt\ electron or muon, requiring
18     \begin{itemize}
19 vimartin 1.10 \item $\pt>30~\GeVc$ and $|\eta|<1.4442 (2.4)$ for electrons (muons)
20     \item muon ID criteria is based on the 2012 POG recommended tight working point
21     \item electron ID critera is based on the 2012 POG recommended medium working point
22     \item PF-based isolation ($\Delta R < 0.3$, $\Delta\beta$ corrected) relative $<$ 0.15 and absolute $<$ 5~GeV
23     \item $|\pt(\rm{PF}_{lep}) - \pt(\rm{RECO}_{lep})| < 10~\GeV$
24     \item $E/p_{in} < 4$ (electrons only)
25 vimartin 1.2 \end{itemize}
26     \item require at least 4 PF jets in the event with $\pt>30~\GeV$
27 vimartin 1.7 within $|\eta|<2.5$ out of which at least 1 satisfies the CSV
28     medium working point b-tagging requirement
29 vimartin 1.2 \item require moderate $\met>50~\GeV$
30 benhoob 1.1 \end{itemize}
31    
32 vimartin 1.12 %Table~\ref{tab:preselectionyield} shows the yields in data and MC without any corrections for this preselection region.
33 fkw 1.6
34 vimartin 1.12 %\begin{table}[!h]
35     %\begin{center}
36     %\begin{tabular}{c|c}
37     %\hline
38     %\hline
39     %\end{tabular}
40     %\caption{ Raw Data and MC predictions without any corrections are shown after preselection. \label{tab:preselectionyield}}
41     %\end{center}
42     %\end{table}
43 fkw 1.6
44 vimartin 1.7 \subsection{Signal Region Selection}
45    
46 vimartin 1.8 [MOTIVATIONAL BLURB ON MET AND MT, \\
47     CAN ADD SIGNAL VS. TTBAR MC PLOT \\
48     ADD SIGNAL YIELDS FOR AVAILABLE POINTS, \\
49     DISCUSS CHOICE SIG REGIONS]
50    
51 vimartin 1.7 The signal regions (SRs) are selected to improve the sensitivity for the
52     single lepton requirements and cover a range of scalar top
53     scenarios. The \mt\ and \met\ variables are used to define the signal
54     regions and the requirements are listed in Table~\ref{tab:srdef}.
55    
56 fkw 1.6 \begin{table}[!h]
57     \begin{center}
58 vimartin 1.7 \begin{tabular}{l|c|c}
59 fkw 1.6 \hline
60 vimartin 1.7 Signal Region & Minimum \mt\ [GeV] & Minimum \met\ [GeV] \\
61 fkw 1.6 \hline
62     \hline
63 vimartin 1.7 SRA & 150 & 100 \\
64     SRB & 120 & 150 \\
65     SRC & 120 & 200 \\
66     SRD & 120 & 250 \\
67     SRE & 120 & 300 \\
68 fkw 1.6 \hline
69     \end{tabular}
70 vimartin 1.7 \caption{ Signal region definitions based on \mt\ and \met\
71     requirements. These requirements are applied in addition to the
72     baseline single lepton selection.
73     \label{tab:srdef}}
74 fkw 1.6 \end{center}
75     \end{table}
76    
77 vimartin 1.7 Table~\ref{tab:srrawmcyields} shows the expected number of SM
78     background yields for the SRs. A few stop signal yields for four
79     values of the parameters are also shown for comparison. The signal
80     regions with looser requirements are sensitive to lower stop masses
81     M(\sctop), while those with tighter requirements are more sensitive to
82     higher M(\sctop).
83    
84 fkw 1.6 \begin{table}[!h]
85     \begin{center}
86 vimartin 1.10 \begin{tabular}{l||c|c|c|c|c}
87 fkw 1.6 \hline
88 vimartin 1.10 Sample & SRA & SRB & SRC & SRD & SRE\\
89 fkw 1.6 \hline
90     \hline
91 vimartin 1.13 \ttdl\ & $619 \pm 9$& $366 \pm 7$& $127 \pm 4$& $44 \pm 2$& $17 \pm 1$ \\
92     \ttsl\ \& single top (1\Lep) & $95 \pm 3$& $67 \pm 3$& $15 \pm 1$& $6 \pm 1$& $2 \pm 1$ \\
93     \wjets\ & $29 \pm 2$& $15 \pm 2$& $6 \pm 1$& $3 \pm 1$& $1 \pm 0$ \\
94     Rare & $59 \pm 3$& $38 \pm 3$& $16 \pm 2$& $8 \pm 1$& $4 \pm 1$ \\
95 fkw 1.6 \hline
96 vimartin 1.13 Total & $802 \pm 10$& $486 \pm 8$& $164 \pm 5$& $62 \pm 3$& $23 \pm 2$ \\
97 fkw 1.6 \hline
98     \end{tabular}
99 vimartin 1.7 \caption{ Expected SM background contributions, including both muon
100 claudioc 1.9 and electron channels. This is ``dead reckoning'' MC with no
101     correction.
102     It is meant only as a general guide. The uncertainties are statistical only. ADD
103 vimartin 1.7 SIGNAL POINTS.
104     \label{tab:srrawmcyields}}
105 fkw 1.6 \end{center}
106     \end{table}
107    
108 vimartin 1.8 \subsection{Control Region Selection}
109 fkw 1.5
110 vimartin 1.8 [1 PARAGRAPH BLURB RELATING BACKGROUNDS (IN TABLE FROM PREVIOUS SECTION)
111     TO INTRODUCE CONTROL REGIONS]
112 fkw 1.5
113 vimartin 1.7 Control regions (CRs) are used to validate the background estimation
114     procedure and derive systematic uncertainties for some
115     contributions. The CRs are selected to have similar
116     kinematics to the SRs, but have a different requirement in terms of
117     number of b-tags and number of leptons, thus enhancing them in
118     different SM contributions. The four CRs used in this analysis are
119     summarized in Table~\ref{tab:crdef}.
120 fkw 1.5
121 vimartin 1.7 \begin{table}
122 fkw 1.6 \begin{center}
123 vimartin 1.7 {\small
124     \begin{tabular}{l|c|c|c}
125 fkw 1.6 \hline
126 vimartin 1.7 Selection & \multirow{2}{*}{exactly 1 lepton} & \multirow{2}{*}{exactly 2
127     leptons} & \multirow{2}{*}{1 lepton + isolated
128     track}\\
129     Criteria & & & \\
130     \hline
131     \hline
132     \multirow{4}{*}{0 b-tags}
133     & CR1) W+Jets dominated:
134     & CR2) apply \Z-mass constraint
135     & CR3) not used \\
136     &
137     & $\rightarrow$ Z+Jets dominated: Validate
138     & \\
139     & Validate W+Jets \mt\ tail
140     & \ttsl\ \mt\ tail comparing
141     & \\
142     &
143     & data vs. MC ``pseudo-\mt ''
144     & \\
145     \hline
146     \multirow{4}{*}{$\ge$ 1 b-tags}
147     &
148     & CR4) Apply \Z-mass veto
149     & CR5) \ttdl, \ttlt\ and \\
150     & SIGNAL
151     & $\rightarrow$ \ttdl\ dominated: Validate
152     & \ttlf\ dominated: Validate \\
153     & REGION
154     & ``physics'' modelling of \ttdl\
155     & \Tau\ and fake lepton modeling/\\
156     &
157     &
158     & detector effects in \ttdl\ \\
159 fkw 1.6 \hline
160     \end{tabular}
161 vimartin 1.7 }
162     \caption{Summary of signal and control regions.
163     \label{tab:crdef}%\protect
164     }
165 fkw 1.6 \end{center}
166     \end{table}
167 fkw 1.5
168 vimartin 1.7
169     \subsection{MC Corrections}
170    
171     [UPDATE SECTION]
172    
173     \subsubsection{Corrections to Jets and \met}
174 benhoob 1.1
175 vimartin 1.8 [UPDATE, ADD FEW MORE DETAILS ON WHAT IS DONE HERE]
176    
177 vimartin 1.2 The official recommendations from the Jet/MET group are used for
178     the data and MC samples. In particular, the jet
179     energy corrections (JEC) are updated using the official recipe.
180     L1FastL2L3Residual (L1FastL2L3) corrections are applied for data (MC),
181     based on the global tags GR\_R\_42\_V23 (DESIGN42\_V17) for
182     data (MC). In addition, these jet energy corrections are propagated to
183     the \met\ calculation, following the official prescription for
184 vimartin 1.7 deriving the Type I corrections.
185    
186     Events with anomalous ``rho'' pile-up corrections are excluded from the sample since these
187 vimartin 1.2 correspond to events with unphysically large \met\ and \mt\ tail
188 vimartin 1.7 signal region. In addition, the recommended MET filters are applied.
189 vimartin 1.2
190 benhoob 1.3
191 vimartin 1.7 \subsubsection{Branching Fraction Correction}
192 vimartin 1.2
193     The leptonic branching fraction used in some of the \ttbar\ MC samples
194 benhoob 1.3 differs from the value listed in the PDG $(10.80 \pm 0.09)\%$.
195 vimartin 1.2 Table.~\ref{tab:wlepbf} summarizes the branching fractions used in
196     the generation of the various \ttbar\ MC samples.
197     For \ttbar\ samples with the incorrect leptonic branching fraction, event
198     weights are applied based on the number of true leptons and the ratio
199     of the corrected and incorrect branching fractions.
200    
201     \begin{table}[!h]
202     \begin{center}
203     \begin{tabular}{c|c}
204     \hline
205     \ttbar\ Sample - Event Generator & Leptonic Branching Fraction\\
206     \hline
207     \hline
208     Madgraph & 0.111\\
209     MC@NLO & 0.111\\
210     Pythia & 0.108\\
211     Powheg & 0.108\\
212     \hline
213     \end{tabular}
214     \caption{Leptonic branching fractions for the various \ttbar\ samples
215     used in the analysis. The primary \ttbar\ MC sample produced with
216     Madgraph has a branching fraction that is almost $3\%$ higher than
217     the PDG value. \label{tab:wlepbf}}
218     \end{center}
219     \end{table}
220    
221 vimartin 1.7
222 benhoob 1.11 \subsubsection{Lepton Selection Efficiency Measurements}
223 vimartin 1.7
224 benhoob 1.11 [TO BE UDPATED WITH T\&P STUDIES ON ID,ISO EFFICIENCIES]
225 vimartin 1.7
226 benhoob 1.11
227     \subsubsection{Trigger Efficiency Measurements}
228    
229     In this section we measure the efficiencies of the single lepton triggers, HLT\_IsoMu24(\_eta2p1) for muons and HLT\_Ele27\_WP80 for electrons, using a tag-and-probe
230     approach. The tag is required to pass the full offline analysis selection and have \pt\ $>$ 30 GeV, $|\eta|<2.1$, and be matched to the single
231     lepton trigger. The probe is also required to pass the full offline analysis selection and have $|\eta|<2.1$, but the \pt\ requirement is relaxed to 20 GeV
232     in order to measure the \pt\ turn-on curve. The tag-probe pair is required to have opposite-sign and an invariant mass in the range 76--106 GeV.
233     The measured trigger efficiencies are displayed in Fig.~\ref{fig:trigeff} and summarized in Table~\ref{tab:mutriggeff} (muons) and Table~\ref{tab:eltriggeff} (electrons).
234     These trigger efficiencies will be applied to the MC when used to predict data yields selected by single lepton triggers. [THESE TRIGGER EFFICIENCIES TO BE APPLIED TO MC]
235    
236    
237     \begin{figure}[!ht]
238     \begin{center}
239     \begin{tabular}{cc}
240     \includegraphics[width=0.4\textwidth]{plots/mutrig_pt_etabins.pdf} &
241     \includegraphics[width=0.4\textwidth]{plots/eltrig_pt_etabins.pdf} \\
242     \end{tabular}
243     \caption{\label{fig:trigeff}
244     Efficiency for the single muon trigger HLT\_IsoMu24(\_eta2p1) (left) and single electron trigger HLT\_Ele27\_WP80 (right) as a function of lepton \pt,
245     for several bins in lepton $|\eta|$.
246     }
247     \end{center}
248     \end{figure}
249    
250     \clearpage
251    
252     \begin{table}[htb]
253     \begin{center}
254     \footnotesize
255     \caption{\label{tab:mutriggeff}
256     Summary of the single muon trigger efficiency HLT\_IsoMu24(\_eta2p1). Uncertainties are statistical.}
257     \begin{tabular}{c|c|c|c}
258    
259     \hline
260     \hline
261     \pt\ range [GeV] & $|\eta|<0.8$ & $0.8<|\eta|<1.5$ & $1.5<|\eta|<2.1$ \\
262     \hline
263     20 - 22 & 0.00 $\pm$ 0.000 & 0.00 $\pm$ 0.000 & 0.00 $\pm$ 0.000 \\
264     22 - 24 & 0.03 $\pm$ 0.001 & 0.05 $\pm$ 0.001 & 0.11 $\pm$ 0.002 \\
265     24 - 26 & 0.87 $\pm$ 0.002 & 0.78 $\pm$ 0.002 & 0.76 $\pm$ 0.003 \\
266     26 - 28 & 0.90 $\pm$ 0.001 & 0.81 $\pm$ 0.002 & 0.78 $\pm$ 0.002 \\
267     28 - 30 & 0.91 $\pm$ 0.001 & 0.81 $\pm$ 0.002 & 0.79 $\pm$ 0.002 \\
268     30 - 32 & 0.91 $\pm$ 0.001 & 0.81 $\pm$ 0.001 & 0.80 $\pm$ 0.002 \\
269     32 - 34 & 0.92 $\pm$ 0.001 & 0.82 $\pm$ 0.001 & 0.80 $\pm$ 0.002 \\
270     34 - 36 & 0.93 $\pm$ 0.001 & 0.82 $\pm$ 0.001 & 0.81 $\pm$ 0.001 \\
271     36 - 38 & 0.93 $\pm$ 0.001 & 0.83 $\pm$ 0.001 & 0.81 $\pm$ 0.001 \\
272     38 - 40 & 0.93 $\pm$ 0.001 & 0.83 $\pm$ 0.001 & 0.82 $\pm$ 0.001 \\
273     40 - 50 & 0.94 $\pm$ 0.000 & 0.84 $\pm$ 0.000 & 0.82 $\pm$ 0.001 \\
274     50 - 60 & 0.95 $\pm$ 0.000 & 0.84 $\pm$ 0.001 & 0.83 $\pm$ 0.001 \\
275     60 - 80 & 0.95 $\pm$ 0.001 & 0.84 $\pm$ 0.002 & 0.83 $\pm$ 0.002 \\
276     80 - 100 & 0.94 $\pm$ 0.002 & 0.84 $\pm$ 0.004 & 0.83 $\pm$ 0.006 \\
277     100 - 150 & 0.94 $\pm$ 0.003 & 0.84 $\pm$ 0.005 & 0.83 $\pm$ 0.008 \\
278     150 - 200 & 0.93 $\pm$ 0.006 & 0.84 $\pm$ 0.011 & 0.82 $\pm$ 0.018 \\
279     $>$200 & 0.92 $\pm$ 0.010 & 0.82 $\pm$ 0.017 & 0.82 $\pm$ 0.031 \\
280     \hline
281     \hline
282    
283     \end{tabular}
284     \end{center}
285     \end{table}
286    
287     \begin{table}[htb]
288     \begin{center}
289     \footnotesize
290     \caption{\label{tab:eltriggeff}
291     Summary of the single electron trigger efficiency HLT\_Ele27\_WP80. Uncertainties are statistical.}
292     \begin{tabular}{c|c|c}
293    
294     \hline
295     \hline
296     \pt\ range [GeV] & $|\eta|<1.5$ & $1.5<|\eta|<2.1$ \\
297     \hline
298     20 - 22 & 0.00 $\pm$ 0.000 & 0.00 $\pm$ 0.000 \\
299     22 - 24 & 0.00 $\pm$ 0.000 & 0.00 $\pm$ 0.001 \\
300     24 - 26 & 0.00 $\pm$ 0.000 & 0.02 $\pm$ 0.001 \\
301     26 - 28 & 0.08 $\pm$ 0.001 & 0.18 $\pm$ 0.003 \\
302     28 - 30 & 0.61 $\pm$ 0.002 & 0.50 $\pm$ 0.004 \\
303     30 - 32 & 0.86 $\pm$ 0.001 & 0.63 $\pm$ 0.003 \\
304     32 - 34 & 0.88 $\pm$ 0.001 & 0.68 $\pm$ 0.003 \\
305     34 - 36 & 0.90 $\pm$ 0.001 & 0.70 $\pm$ 0.002 \\
306     36 - 38 & 0.91 $\pm$ 0.001 & 0.72 $\pm$ 0.002 \\
307     38 - 40 & 0.92 $\pm$ 0.001 & 0.74 $\pm$ 0.002 \\
308     40 - 50 & 0.94 $\pm$ 0.000 & 0.76 $\pm$ 0.001 \\
309     50 - 60 & 0.95 $\pm$ 0.000 & 0.77 $\pm$ 0.002 \\
310     60 - 80 & 0.96 $\pm$ 0.001 & 0.78 $\pm$ 0.003 \\
311     80 - 100 & 0.96 $\pm$ 0.002 & 0.80 $\pm$ 0.008 \\
312     100 - 150 & 0.96 $\pm$ 0.002 & 0.79 $\pm$ 0.010 \\
313     150 - 200 & 0.97 $\pm$ 0.004 & 0.76 $\pm$ 0.026 \\
314     $>$200 & 0.97 $\pm$ 0.005 & 0.81 $\pm$ 0.038 \\
315     \hline
316     \hline
317    
318     \end{tabular}
319     \end{center}
320     \end{table}
321    
322     \clearpage