[ViewVC] Diff of: cvsroot/UserCode/Vuko/Notes/WZCSA07/selection.tex

Comparing UserCode/Vuko/Notes/WZCSA07/selection.tex (file contents):
Revision 1.3 by vuko, Fri Jun 20 12:00:10 2008 UTC vs.
Revision 1.7 by vuko, Fri Jun 20 17:09:36 2008 UTC

+\label{sec:eventReconstruction}
+The four possible final states of \WZ
-<
+production with electrons and muons are studied, $\rm e^\pm \epem$, $\mu^\pm \epem$, $\rm e^\pm \mu^+\mu^-$
->
+production with electrons and muons in the final state are studied, $\rm e^\pm \epem$, $\mu^\pm \epem$, $\rm e^\pm \mu^+\mu^-$
+and $\mu^\pm \mu^+\mu^-$. They are associated to four possible classes,
+denoted as follows:
+\begin{itemize}
+\subsection{Trigger selection and efficiencies}
+Events stemming from the three-lepton final states of $\WZ$ production
-<
+are collected by the electron and muon triggers. For each channel,
->
+are collected by the electron and/or muon triggers. For each channel,
+a minimun number of HLT requirements is chosen while keeping
+the HLT efficiency for selected events close to 100\%. The same
+HLT requirements are used for channels with the same Z decay mode:
+An additional isolation criterion requires that the energy
+measured in the calorimeters within a $\Delta R = 0.3$ cone around the
+muon must be smaller than 3 GeV and the sum of the $p_t$ of tracks
-<
+within a $\Delta R = 0.25$ cone around the muon must be smaller than 2
-<
+GeV. These cuts reduce the background from muons originated in
->
+within a $\Delta R = 0.25$ cone around the muon must be smaller than 2 \gev.
->
+These cuts reduce the background from muons originated in
+\b-quark decays of the $\Zbbbar$ background, which are close to tracks
+and clusters from the other \b-quark decay products.
-+
+\begin{table}[tbp]
-+
+\begin{tabular}{|l|c|c|c|c|} \hline
-+
+              &  $3e$ & $2e1\mu$ & $2\mu 1e$ & $3\mu$ \\ \hline \hline
-+
+\multicolumn{5}{|c|}{Lepton selection} \\ \hline
-+
+Electrons     &   \multicolumn{3}{|c|}{{\tt SimpleLoose} requirements for Z reconstruction} & \\
-+
+              &   \multicolumn{3}{|c|}{{\tt SimpleTight} requirements for W} &  \\ \hline
-+
+Muons         &  &  \multicolumn{3}{|c|}{ Track Isolation:$ {\tt IsoTrack}(\Delta R= 0.25) < 2 \gev$}  \\
-+
+              &  &  \multicolumn{3}{|c|}{ Calorimetric Isolation:$  {\tt IsoCalo}(\Delta R = 0.3)  < 5 \gev$}  \\
-+
+              &  &  \multicolumn{3}{|c|}{$S_{IP}=IP/\sigma_{IP}<3$ }  \\ \hline
-+
+HLT requirement & \multicolumn{2}{|c|}{ HLTSingleElectron or HLTDoubleElectronRelaxed}
-+
+                & \multicolumn{2}{|c|}{  HLTSingleMuonIso} \\ \hline
-+
+\multicolumn{5}{|c|}{Z reconstruction} \\ \hline
-+
+Lepton cuts   &  \multicolumn{4}{|c|}{for both Z leptons: $p_t > 15 GeV$} \\
-+
+Mass window   &  \multicolumn{4}{|c|}{$50 \gev < M_Z < 120 \gev $ } \\
-+
+Second Z veto &  \multicolumn{4}{|c|}{No independent second Z candidate with $50 \gev < M_Z < 120 \gev $ } \\ \hline
-+
+\multicolumn{5}{|c|}{W lepton selection} \\ \hline
-+
-+
+Other cuts    &     &        & $\Delta R(\mu_Z,e_W)>0.1$ &  \\ \hline
-+
+Signal region  &    \multicolumn{4}{|c|}{$81 \gev < M_Z < 101 \gev $ } \\ \hline \hline
-+
-+
+\end{tabular}
-+
+\caption{Summary of all cuts used in the WZ selection}
-+
+\label{tab:allcuts}
-+
+\end{table}
-+
-+
-+
+\begin{figure}[p]
-+
+  \begin{center}
-+
+  \scalebox{0.6}{\includegraphics{figs/wlpt_cuteff.eps}}
-+
+  \caption{Efficiency for signal and background as a function
-+
+    of the cut value on the \W-boson lepton transverse momentum.
-+
+    All other cuts but the cut on this variable are applied.
-+
+    Only events with 81.1 GeV $< M_Z < $ 101.1 \gev
-+
+    are considered.}
-+
+  \label{fig:wlpt_cuteff}
-+
+  \end{center}
-+
+%\end{figure}
-+
-+
+%\begin{figure}[bt]
-+
+  \begin{center}
-+
+  \scalebox{0.6}{\includegraphics{figs/wlpt_cutS.eps}}
-+
+  \caption{Signal significance as a function of the cut value on
-+
+    the \W-boson lepton transverse momentum. All other cuts but
-+
+    the cut on this variable are applied. Only events with
-+
+.1 GeV $< M_Z < $ 101.1 \gev are considered.}
-+
+  \label{fig:wlpt_cutS}
-+
+  \end{center}
-+
+\end{figure}
-+
-+
+\subsection{\WZ candidate selection}
+Events are accepted if they contain at least three charged leptons,
+the additional leptons are not considered further.
+The transverse momentum of this lepton is required to be larger
+than 20 GeV. This last requirement is effective in rejecting
-<
+the \Zbbbar and \Zjets backgrounds, and the cut value is chosen in
->
+the \Zbbbar and \Zjets backgrounds, see Figure~\ref{fig:wlpt_cuteff},
->
+and the cut value is chosen in
+the range that maximises the significance as shown in
-<
+Figure~\ref{fig:s_vs_wlpt}.
->
+Figure~\ref{fig:wlpt_cutS}.
->
->
+An additional requirement on the isolation between electron and muons is applied
->
+for the $2\mu 1e$ channel, by demanding $\Delta R$ between the electron associated
->
+to the \W-decay and any of the two muons associated to the \Z-decay be greater than
->
+.1. This requirement allows to suppress the contributions of $\Z \to \mu\mu$
->
+decays, where one of the two muons radiates a photon which is reconstructed
->
+as electrons, possibly after conversion, which shows up as a peak at  around 60 GeV
->
+in the Z mass distribution, as shown in figure~\ref{fig:Z2mu1e_60GeVPeak}.
->
->
+The summary of the selection can be seen in Table~\ref{tab:allcuts}.
+The expected number of events passing the various steps of the selection
+is listed in Tables~\ref{tab:sel-effA} and~\ref{tab:sel-effB}.
+\subsection{Signal extraction}
-+
+\input D0Matrix
-+
+\input zjetbackground
-+
+\subsection{Systematic uncertainties}
-+
+\input Sys
-+
+\begin{figure}[bt]
-+
+  \begin{center}
-+
+  \scalebox{0.8}{\includegraphics{figs/met_by_channel.eps}}
-+
+  \caption{Missing transverse mass for the four signal categories.
-+
+    The distributions  show the number of expected events
-+
+    for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 \gev
-+
+    are shown. All selection cuts are applied.}
-+
+  \label{fig:met}
-+
+  \end{center}
-+
+\end{figure}
+\begin{figure}[bt]
+  \begin{center}
+  \scalebox{0.8}{\includegraphics{figs/mtw_by_channel.eps}}
+  \caption{W transverse mass for the four signal categories.
+    The distributions  show the number of expected events
-<
+    for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 GeV are shown.}
->
+    for $1 fb^{-1}$. Only events with 81.1 GeV $< M_Z < $ 101.1 GeV are shown.
->
+    All selection cuts are applied.}
+  \label{fig:mtw}
+  \end{center}
+\end{figure}
-+
-+
-+
-+
-+
+\begin{table}[tbp]
-+
+\begin{center}
-+
+\begin{tabular}{lccccc}
-+
+\hline \hline
-+
+ & \multicolumn{5}{c}{$Z \to ee $} \\
-+
+   &  $W \to e$
-+
+   &  $W \to \mu$
-+
+   &  $W \to \tau \to e$
-+
+   &  $W \to \tau \to \mu$
-+
+   &  $W \to \tau \to hadrons$
-+
+\\ \hline
-+
+$3e$       &  17.4 \%  &  0.0319 \%  &  6.42 \%  &  0 \%  &  0.162 \% \\
-+
+$2e1\mu$   &  0 \%  &  18.6 \%  &  0 \%  &  5.53 \%  &  0.0485 \% \\
-+
+$2\mu1e$   &  0 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
-+
+$3\mu$     &  0 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
-+
+\hline \hline
-+
+ & \multicolumn{5}{c}{$Z \to \mu\mu $} \\
-+
+   &  $W \to e$
-+
+   &  $W \to \mu$
-+
+   &  $W \to \tau \to e$
-+
+   &  $W \to \tau \to \mu$
-+
+   &  $W \to \tau \to hadrons$
-+
+\\ \hline
-+
+$3e$        &  0 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
-+
+$2e1\mu$   &  0.0104 \%  &  0 \%  &  0 \%  &  0 \%  &  0 \% \\
-+
+$2\mu1e$   &  19.6 \%  &  0.0208 \%  &  5.56 \%  &  0 \%  &  0.18 \% \\
-+
+$3\mu$     &  0 \%  &  23.4 \%  &  0.0573 \%  &  6.77 \%  &  0.0164 \% \\
-+
+\hline \hline
-+
+\end{tabular}
-+
+\end{center}
-+
+\caption{Selection efficiency for signal events in the four selection channels for the different
-+
+  generated \W and \Z decay channels.}
-+
+\label{tab:wz-effimatrix}
-+
+\end{table}
-+
-+
-+
+\begin{table}[tbp]
-+
+\begin{center}
-+
+\begin{tabular}{llcc} \hline
-+
+  & & \multicolumn{2}{c}{Generated decay:} \\
-+
+  & & \multicolumn{2}{c}{$Z \to ee $} \\
-+
+Selection channel  &    &  $W \to e$   &  $W \to \mu$ \\ \hline
-+
+\hline \hline
-+
+\multicolumn{4}{c}{all} \\ \hline
-+
+$3e$        & all & 1644         & 3    \\
-+
+$3e$        & matched Z & 0.937+/-0.00598 & 1+/-0\\
-+
+$3e$        & matched W & 0.915+/-0.00688 & 0+/--1\\
-+
+$3e$        & matched WZ & 0.914+/-0.00691 & 0+/--1\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline
-+
+$3e$        & all & 1602         & 0    \\
-+
+$3e$        & matched Z & 0.938+/-0.00604 & -1+/--1\\
-+
+$3e$        & matched W & 0.915+/-0.00696 & -1+/--1\\
-+
+$3e$        & matched WZ & 0.914+/-0.00699 & -1+/--1\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline
-+
+$3e$        & all & 42   & 3    \\
-+
+$3e$        & matched Z & 0.929+/-0.0397 & 1+/-0\\
-+
+$3e$        & matched W & 0.905+/-0.0453 & 0+/--1\\
-+
+$3e$        & matched WZ & 0.905+/-0.0453 & 0+/--1\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{all} \\ \hline
-+
+$2e1\mu$   & all & 0     & 1746 \\
-+
+$2e1\mu$   & matched Z & -1+/--1 & 0.999+/-0.000573\\
-+
+$2e1\mu$   & matched W & -1+/--1 & 1+/-0\\
-+
+$2e1\mu$   & matched WZ & -1+/--1 & 0.999+/-0.000573\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline
-+
+$2e1\mu$   & all & 0     & 1715 \\
-+
+$2e1\mu$   & matched Z & -1+/--1 & 0.999+/-0.000583\\
-+
+$2e1\mu$   & matched W & -1+/--1 & 1+/-0\\
-+
+$2e1\mu$   & matched WZ & -1+/--1 & 0.999+/-0.000583\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline
-+
+$2e1\mu$   & all & 0     & 31   \\
-+
+$2e1\mu$   & matched Z & -1+/--1 & 1+/-0\\
-+
+$2e1\mu$   & matched W & -1+/--1 & 1+/-0\\
-+
+$2e1\mu$   & matched WZ & -1+/--1 & 1+/-0\\ \hline \hline
-+
+\end{tabular}
-+
+\end{center}
-+
+\caption{Fractions of events with correctly matched leptons
-+
+  to true decay product of \W and \Z decays for final states
-+
+  with generated $\Z\to ee$ decays}
-+
+\label{tab:wz-matcheffi-Zee}
-+
+\end{table}
-+
-+
-+
-+
+\begin{table}[tbp]
-+
+\begin{center}
-+
+\begin{tabular}{llcc} \hline
-+
+  & & \multicolumn{2}{c}{Generated decay:} \\
-+
+ & & \multicolumn{2}{c}{$Z \to \mu\mu $} \\
-+
+Selection channel  &    &  $W \to e$   &  $W \to \mu$
-+
+\\ \hline
-+
+\hline \hline
-+
+\multicolumn{4}{c}{all} \\ \hline
-+
+$2\mu1e$   & all & 1895  & 2    \\
-+
+$2\mu1e$   & matched Z & 1+/-0 & 1+/-0\\
-+
+$2\mu1e$   & matched W & 0.985+/-0.00282 & 0+/--1\\
-+
+$2\mu1e$   & matched WZ & 0.985+/-0.00282 & 0+/--1\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline
-+
+$2\mu1e$   & all & 1847  & 0    \\
-+
+$2\mu1e$   & matched Z & 1+/-0 & -1+/--1\\
-+
+$2\mu1e$   & matched W & 0.986+/-0.00274 & -1+/--1\\
-+
+$2\mu1e$   & matched WZ & 0.986+/-0.00274 & -1+/--1\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline
-+
+$2\mu1e$   & all & 48    & 2    \\
-+
+$2\mu1e$   & matched Z & 1+/-0 & 1+/-0\\
-+
+$2\mu1e$   & matched W & 0.938+/-0.0349 & 0+/--1\\
-+
+$2\mu1e$   & matched WZ & 0.938+/-0.0349 & 0+/--1\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{all} \\ \hline
-+
+$3\mu$     & all & 0     & 2251 \\
-+
+$3\mu$     & matched Z & -1+/--1 & 0.943+/-0.00488\\
-+
+$3\mu$     & matched W & -1+/--1 & 0.933+/-0.00526\\
-+
+$3\mu$     & matched WZ & -1+/--1 & 0.933+/-0.00526\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{exactly 1 W lepton candidate} \\ \hline
-+
+$3\mu$     & all & 0     & 2207 \\
-+
+$3\mu$     & matched Z & -1+/--1 & 0.944+/-0.0049\\
-+
+$3\mu$     & matched W & -1+/--1 & 0.934+/-0.00529\\
-+
+$3\mu$     & matched WZ & -1+/--1 & 0.934+/-0.00529\\
-+
+\hline \hline
-+
+\multicolumn{4}{c}{more than 1 W lepton candidate} \\ \hline
-+
+$3\mu$     & all & 0     & 44   \\
-+
+$3\mu$     & matched Z & -1+/--1 & 0.909+/-0.0433\\
-+
+$3\mu$     & matched W & -1+/--1 & 0.909+/-0.0433\\
-+
+$3\mu$     & matched WZ & -1+/--1 & 0.909+/-0.0433\\ \hline \hline
-+
+\end{tabular}
-+
+\end{center}
-+
+\caption{Fractions of MC \WZ events with correctly matched leptons
-+
+  to true decay product of \W and \Z decays for final states
-+
+  with generated $\Z\to \mu\mu$ decays}
-+
+\label{tab:wz-matcheffi-Zmumu}
-+
+\end{table}
-+

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing UserCode/Vuko/Notes/WZCSA07/selection.tex (file contents): Revision 1.3 by vuko, Fri Jun 20 12:00:10 2008 UTC vs. Revision 1.7 by vuko, Fri Jun 20 17:09:36 2008 UTC

Diff Legend

Comparing UserCode/Vuko/Notes/WZCSA07/selection.tex (file contents):
Revision 1.3 by vuko, Fri Jun 20 12:00:10 2008 UTC vs.
Revision 1.7 by vuko, Fri Jun 20 17:09:36 2008 UTC