claudioc/OSNote2010/eventsel.tex

\section{Event Preselection}
\label{sec:eventSel}
%{\color{red} This needs to be fixed up -- probably many mistakes present.}\\
As mentioned in the introduction, the preselection is based on the 
$t\bar{t}$ analysis.  We select events with two opposite sign isolated
leptons ($ee$, $e\mu$, or $\mu\mu$); one of the leptons must 
have $P_T > 20$ GeV,
the other one must have $P_T > 10$ GeV\footnote{In case of events with 
more than two such leptons, we select the pair that maximizes the scalar 
sum of lepton $P_T$'s.}; 
there must be two JPT
jets of $P_T > 30$ GeV and $|\eta| < 2.5$; the scalar sum of the 
$P_T$ of all such jets must exceed 100 GeV; jets must pass
{\tt caloJetId} and be separated by $\Delta R >$ 0.4 from the 
any lepton passing the selection described below.  
{\color{red}The 11 pb iteration only does this for the two selected
leptons.}
Finally $\met > 50$ GeV
(we use tcMet). More details are given in the subsections below.

\subsection{Event Cleanup}
\label{sec:cleanup}
\begin{itemize}
\item Scraping cut: if there are $\geq$ 10 tracks, require at
least 25\% of them to be high purity.
\item Require at least one good vertex:
\begin{itemize}
\item not fake
\item ndof $>$ 4
\item $|\rho| < 2$ cm
\item $|z| < 24$ cm.  
\end{itemize}
\end{itemize}


\subsection{Muon Selection}
\label{sec:muon}

Muon candidates are RECO muon objects passing the following
requirements:
\begin{itemize}

\item $|\eta| < 2.4$.

\item Global Muon and Tracker Muon.

\item $\chi^2$/ndof of global fit $<$ 10.

\item At least 11 hits in the tracker fit.

\item Transverse impact parameter with respect to the beamspot $<$ 200 $\mu$m.

\item $Iso \equiv $ $E_T^{\rm iso}$/Max(20 GeV, $P_T$) $<$ 0.15.  
$E_T^{\rm iso}$
is defined as the sum of transverse energy/momentum deposits in ecal,
hcal, and tracker, in a cone of 0.3.

\item At least one of the hits from the 
standalone muon must be used in the global fit.

%\item Require tracker $\Delta P_T/P_T < 0.1$. This cut was not in the original top analysis.
%It is motivated by the observation of
%poorly measured muons in data with large
%relative $P_T$ uncertainty, giving significant contributions to the \met.
%{\color{red} This is not applied to the 11 pb iteration.}


\end{itemize}


\subsection{Electron Selection}
\label{sec:electron}

Electron candidates are RECO GSF electrons passing the following
requirements:

\begin{itemize}

\item $P_T > 10$ GeV.  (The $t\bar{t}$ analysis uses 20 GeV but for
completeness we calculate FR down to 10 GeV).

\item $|\eta| < 2.5$.

\item SuperCluster $E_T > 10$ GeV.  

\item The electron must be ecal seeded.

\item VBTF90 identification\cite{ref:vbtf}.

\item Transverse impact parameter with respect to the beamspot $<$ 400 $\mu$m.

\item $Iso \equiv $ $E_T^{\rm iso}$/Max(20 GeV, $P_T$) $<$ 0.15.  
$E_T^{\rm iso}$
is defined as the sum of transverse energy/momentum deposits in ecal,
hcal, and tracker, in a 
cone of 0.3.  A 1 GeV pedestal is subtracted from the ecal energy 
deposition in the EB, however the ecal energy is never allowed to 
go negative.

\item Electrons with a tracker or global muon within $\Delta R$ of 
0.1 are vetoed.

\item The number of missing expected inner hits must be less than 
two\cite{ref:conv}.

\item Conversion removal via partner track finding: any electron
where an additional GeneralTrack is found with $Dist < 0.02$ cm 
and $\Delta \cot \theta < 0.02$ is vetoed\cite{ref:conv}.

\item Cleaning for ECAL spike (aka Swiss-Cross cleaning) has been applied
at the reconstruction level (CMSSW 38x).

\end{itemize}

\subsection{Invariant mass requirement}
\label{sec:zveto}

We remove $e^+e^-$ and $\mu^+ \mu^-$ events with invariant 
mass between 76 and 106 GeV.  We also remove events
with invariant mass $<$ 10 GeV.

\subsection{Trigger Selection}
\label{sec:trigSel}

Because most of the triggers implemented in the 2nd half of the
2010 run were not implemented in the Monte Carlo, no trigger
selection is applied on Monte Carlo data.  As discussed in 
Section~\ref{sec:trgEff}, a trigger efficiency weight is applied
to each event, based on the trigger efficiencies measured on data.
Trigger efficiency weights are very close to 1.

%For data, we require the logical OR of all (or most?) unprescaled
%single and double lepton triggers that were deployed during the 2010
%run.  These are:
%{\color{red} Here we need to list the triggers, somehow.}

For data, we use a cocktail of unprescaled single 
and double lepton triggers. An event
in the $ee$ final state is required to pass at least 1 
single- or double-electron trigger, a
$\mu\mu$ event is required to pass at least 1 single 
or double-muon trigger, while an $e\mu$ event
is required to pass at least 1 single-muon, single-electron, 
or $e-\mu$ cross trigger. 
% We currently
% do not require MC events to pass any triggers.

\begin{itemize}
\item single-muon triggers
  \begin{itemize}
  \item \verb=HLT_Mu5=
  \item \verb=HLT_Mu7=       
  \item \verb=HLT_Mu9=        
  \item \verb=HLT_Mu11=      
  \item \verb=HLT_Mu13_v1=    
  \item \verb=HLT_Mu15_v1=    
  \item \verb=HLT_Mu17_v1=    
  \item \verb=HLT_Mu19_v1=    
  \end{itemize}
\item double-muon triggers
  \begin{itemize}
  \item \verb=HLT_DoubleMu3=
  \item \verb=HLT_DoubleMu3_v2=
  \item \verb=HLT_DoubleMu5_v1=
  \end{itemize}
\item single-electron triggers
  \begin{itemize}
  \item \verb=HLT_Ele10_SW_EleId_L1R=
  \item \verb=HLT_Ele10_LW_EleId_L1R=
  \item \verb=HLT_Ele10_LW_L1R=
  \item \verb=HLT_Ele10_SW_L1R=
  \item \verb=HLT_Ele15_SW_CaloEleId_L1R=
  \item \verb=HLT_Ele15_SW_EleId_L1R=
  \item \verb=HLT_Ele15_SW_L1R=
  \item \verb=HLT_Ele15_LW_L1R=
  \item \verb=HLT_Ele17_SW_TightEleId_L1R=
  \item \verb=HLT_Ele17_SW_TighterEleId_L1R_v1=
  \item \verb=HLT_Ele17_SW_CaloEleId_L1R=
  \item \verb=HLT_Ele17_SW_EleId_L1R=
  \item \verb=HLT_Ele17_SW_LooseEleId_L1R=
  \item \verb=HLT_Ele17_SW_TighterEleIdIsol_L1R_v2=
  \item \verb=HLT_Ele20_SW_L1R=
  \item \verb=HLT_Ele22_SW_TighterEleId_L1R_v2=
  \item \verb=HLT_Ele32_SW_TightCaloEleIdTrack_L1R_v1=
  \item \verb=HLT_Ele32_SW_TighterEleId_L1R_v2=
  \item \verb=HLT_Ele27_SW_TightCaloEleIdTrack_L1R_v1=
  \item \verb=HLT_Ele22_SW_TighterCaloIdIsol_L1R_v2=
  \item \verb=HLT_Ele22_SW_TighterEleId_L1R_v3=
  \item \verb=HLT_Ele22_SW_TighterCaloIdIsol_L1R_v2=
  \end{itemize}
\item double-electron triggers
  \begin{itemize}
  \item \verb=HLT_DoubleEle15_SW_L1R_v1=                
  \item \verb=HLT_DoubleEle17_SW_L1R_v1=  
  \item \verb=HLT_Ele17_SW_TightCaloEleId_Ele8HE_L1R_v1=
  \item \verb=HLT_Ele17_SW_TightCaloEleId_SC8HE_L1R_v1=
  \item \verb=HLT_DoubleEle10_SW_L1R=
  \item \verb=HLT_DoubleEle5_SW_L1R=
  \end{itemize}
\item e-$\mu$ cross triggers
  \begin{itemize}
  \item \verb=HLT_Mu5_Ele5_v1=
  \item \verb=HLT_Mu5_Ele9_v1=
  \item \verb=HLT_Mu11_Ele8_v1=
  \item \verb=HLT_Mu8_Ele8_v1=
  \item \verb=HLT_Mu5_Ele13_v2=
  \item \verb=HLT_Mu5_Ele17_v1=
  \end{itemize}
\end{itemize}
Revision:	1.9
Committed:	Sat Nov 6 19:51:16 2010 UTC (14 years, 5 months ago) by claudioc
Content type:	application/x-tex
Branch:	MAIN
CVS Tags:	nov8th
Branch point for:	NovSync
Changes since 1.8:	+5 -5 lines
Log Message:	more more better
#	User	Rev	Content
1	claudioc	1.1	\section{Event Preselection}
2			\label{sec:eventSel}
3	claudioc	1.6	%{\color{red} This needs to be fixed up -- probably many mistakes present.}\\
4	claudioc	1.1	As mentioned in the introduction, the preselection is based on the
5			$t\bar{t}$ analysis. We select events with two opposite sign isolated
6			leptons ($ee$, $e\mu$, or $\mu\mu$); one of the leptons must
7			have $P_T > 20$ GeV,
8	claudioc	1.5	the other one must have $P_T > 10$ GeV\footnote{In case of events with
9			more than two such leptons, we select the pair that maximizes the scalar
10			sum of lepton $P_T$'s.};
11			there must be two JPT
12			jets of $P_T > 30$ GeV and $\|\eta\| < 2.5$; the scalar sum of the
13			$P_T$ of all such jets must exceed 100 GeV; jets must pass
14			{\tt caloJetId} and be separated by $\Delta R >$ 0.4 from the
15	claudioc	1.8	any lepton passing the selection described below.
16			{\color{red}The 11 pb iteration only does this for the two selected
17			leptons.}
18			Finally $\met > 50$ GeV
19	claudioc	1.6	(we use tcMet). More details are given in the subsections below.
20	claudioc	1.1
21			\subsection{Event Cleanup}
22			\label{sec:cleanup}
23			\begin{itemize}
24			\item Scraping cut: if there are $\geq$ 10 tracks, require at
25			least 25\% of them to be high purity.
26			\item Require at least one good vertex:
27			\begin{itemize}
28			\item not fake
29			\item ndof $>$ 4
30			\item $\|\rho\| < 2$ cm
31	claudioc	1.3	\item $\|z\| < 24$ cm.
32	claudioc	1.1	\end{itemize}
33			\end{itemize}
34
35
36			\subsection{Muon Selection}
37			\label{sec:muon}
38
39			Muon candidates are RECO muon objects passing the following
40			requirements:
41			\begin{itemize}
42
43	claudioc	1.5	\item $\|\eta\| < 2.4$.
44	claudioc	1.1
45			\item Global Muon and Tracker Muon.
46
47			\item $\chi^2$/ndof of global fit $<$ 10.
48
49			\item At least 11 hits in the tracker fit.
50
51			\item Transverse impact parameter with respect to the beamspot $<$ 200 $\mu$m.
52
53			\item $Iso \equiv $ $E_T^{\rm iso}$/Max(20 GeV, $P_T$) $<$ 0.15.
54			$E_T^{\rm iso}$
55			is defined as the sum of transverse energy/momentum deposits in ecal,
56			hcal, and tracker, in a cone of 0.3.
57
58			\item At least one of the hits from the
59			standalone muon must be used in the global fit.
60
61	claudioc	1.9	%\item Require tracker $\Delta P_T/P_T < 0.1$. This cut was not in the original top analysis.
62			%It is motivated by the observation of
63			%poorly measured muons in data with large
64			%relative $P_T$ uncertainty, giving significant contributions to the \met.
65			%{\color{red} This is not applied to the 11 pb iteration.}
66	claudioc	1.7
67	claudioc	1.6
68	claudioc	1.1	\end{itemize}
69
70
71
72	claudioc	1.2	\subsection{Electron Selection}
73	claudioc	1.1	\label{sec:electron}
74
75			Electron candidates are RECO GSF electrons passing the following
76			requirements:
77
78			\begin{itemize}
79
80			\item $P_T > 10$ GeV. (The $t\bar{t}$ analysis uses 20 GeV but for
81			completeness we calculate FR down to 10 GeV).
82
83			\item $\|\eta\| < 2.5$.
84
85			\item SuperCluster $E_T > 10$ GeV.
86
87			\item The electron must be ecal seeded.
88
89			\item VBTF90 identification\cite{ref:vbtf}.
90
91			\item Transverse impact parameter with respect to the beamspot $<$ 400 $\mu$m.
92
93			\item $Iso \equiv $ $E_T^{\rm iso}$/Max(20 GeV, $P_T$) $<$ 0.15.
94			$E_T^{\rm iso}$
95			is defined as the sum of transverse energy/momentum deposits in ecal,
96			hcal, and tracker, in a
97			cone of 0.3. A 1 GeV pedestal is subtracted from the ecal energy
98			deposition in the EB, however the ecal energy is never allowed to
99			go negative.
100
101			\item Electrons with a tracker or global muon within $\Delta R$ of
102			0.1 are vetoed.
103
104			\item The number of missing expected inner hits must be less than
105			two\cite{ref:conv}.
106
107			\item Conversion removal via partner track finding: any electron
108			where an additional GeneralTrack is found with $Dist < 0.02$ cm
109			and $\Delta \cot \theta < 0.02$ is vetoed\cite{ref:conv}.
110
111	claudioc	1.4	\item Cleaning for ECAL spike (aka Swiss-Cross cleaning) has been applied
112			at the reconstruction level (CMSSW 38x).
113	claudioc	1.1
114			\end{itemize}
115
116	claudioc	1.5	\subsection{Invariant mass requirement}
117	claudioc	1.2	\label{sec:zveto}
118
119			We remove $e^+e^-$ and $\mu^+ \mu^-$ events with invariant
120	claudioc	1.5	mass between 76 and 106 GeV. We also remove events
121			with invariant mass $<$ 10 GeV.
122	claudioc	1.2
123			\subsection{Trigger Selection}
124	claudioc	1.1	\label{sec:trigSel}
125
126			Because most of the triggers implemented in the 2nd half of the
127			2010 run were not implemented in the Monte Carlo, no trigger
128			selection is applied on Monte Carlo data. As discussed in
129			Section~\ref{sec:trgEff}, a trigger efficiency weight is applied
130			to each event, based on the trigger efficiencies measured on data.
131			Trigger efficiency weights are very close to 1.
132
133	claudioc	1.5	%For data, we require the logical OR of all (or most?) unprescaled
134			%single and double lepton triggers that were deployed during the 2010
135			%run. These are:
136			%{\color{red} Here we need to list the triggers, somehow.}
137
138			For data, we use a cocktail of unprescaled single
139			and double lepton triggers. An event
140			in the $ee$ final state is required to pass at least 1
141			single- or double-electron trigger, a
142			$\mu\mu$ event is required to pass at least 1 single
143			or double-muon trigger, while an $e\mu$ event
144			is required to pass at least 1 single-muon, single-electron,
145			or $e-\mu$ cross trigger.
146			% We currently
147			% do not require MC events to pass any triggers.
148	claudioc	1.1
149	claudioc	1.5	\begin{itemize}
150			\item single-muon triggers
151			\begin{itemize}
152			\item \verb=HLT_Mu5=
153			\item \verb=HLT_Mu7=
154			\item \verb=HLT_Mu9=
155			\item \verb=HLT_Mu11=
156			\item \verb=HLT_Mu13_v1=
157			\item \verb=HLT_Mu15_v1=
158			\item \verb=HLT_Mu17_v1=
159			\item \verb=HLT_Mu19_v1=
160			\end{itemize}
161			\item double-muon triggers
162			\begin{itemize}
163			\item \verb=HLT_DoubleMu3=
164			\item \verb=HLT_DoubleMu3_v2=
165			\item \verb=HLT_DoubleMu5_v1=
166			\end{itemize}
167			\item single-electron triggers
168			\begin{itemize}
169			\item \verb=HLT_Ele10_SW_EleId_L1R=
170			\item \verb=HLT_Ele10_LW_EleId_L1R=
171			\item \verb=HLT_Ele10_LW_L1R=
172			\item \verb=HLT_Ele10_SW_L1R=
173			\item \verb=HLT_Ele15_SW_CaloEleId_L1R=
174			\item \verb=HLT_Ele15_SW_EleId_L1R=
175			\item \verb=HLT_Ele15_SW_L1R=
176			\item \verb=HLT_Ele15_LW_L1R=
177			\item \verb=HLT_Ele17_SW_TightEleId_L1R=
178			\item \verb=HLT_Ele17_SW_TighterEleId_L1R_v1=
179			\item \verb=HLT_Ele17_SW_CaloEleId_L1R=
180			\item \verb=HLT_Ele17_SW_EleId_L1R=
181			\item \verb=HLT_Ele17_SW_LooseEleId_L1R=
182			\item \verb=HLT_Ele17_SW_TighterEleIdIsol_L1R_v2=
183			\item \verb=HLT_Ele20_SW_L1R=
184			\item \verb=HLT_Ele22_SW_TighterEleId_L1R_v2=
185			\item \verb=HLT_Ele32_SW_TightCaloEleIdTrack_L1R_v1=
186			\item \verb=HLT_Ele32_SW_TighterEleId_L1R_v2=
187			\item \verb=HLT_Ele27_SW_TightCaloEleIdTrack_L1R_v1=
188			\item \verb=HLT_Ele22_SW_TighterCaloIdIsol_L1R_v2=
189			\item \verb=HLT_Ele22_SW_TighterEleId_L1R_v3=
190			\item \verb=HLT_Ele22_SW_TighterCaloIdIsol_L1R_v2=
191			\end{itemize}
192			\item double-electron triggers
193			\begin{itemize}
194			\item \verb=HLT_DoubleEle15_SW_L1R_v1=
195			\item \verb=HLT_DoubleEle17_SW_L1R_v1=
196			\item \verb=HLT_Ele17_SW_TightCaloEleId_Ele8HE_L1R_v1=
197			\item \verb=HLT_Ele17_SW_TightCaloEleId_SC8HE_L1R_v1=
198			\item \verb=HLT_DoubleEle10_SW_L1R=
199			\item \verb=HLT_DoubleEle5_SW_L1R=
200			\end{itemize}
201			\item e-$\mu$ cross triggers
202			\begin{itemize}
203			\item \verb=HLT_Mu5_Ele5_v1=
204			\item \verb=HLT_Mu5_Ele9_v1=
205			\item \verb=HLT_Mu11_Ele8_v1=
206			\item \verb=HLT_Mu8_Ele8_v1=
207			\item \verb=HLT_Mu5_Ele13_v2=
208			\item \verb=HLT_Mu5_Ele17_v1=
209			\end{itemize}
210			\end{itemize}