8 |
|
\begin{itemize} |
9 |
|
\item $\pt>30~\GeVc$ and $|\eta|<2.5(2.1)$ for \E(\M) |
10 |
|
\item satisfy the identification and isolation requirements detailed |
11 |
< |
in~\cite{ref:osznote} for electrons and in~\cite{ref:osznote} for muons |
11 |
> |
in the same-sign SUSY analysis (SUS-11-010) for electrons and the opposite-sign |
12 |
> |
SUSY analysis (SUS-11-011) for muons |
13 |
|
\end{itemize} |
14 |
|
\item require at least 4 PF jets in the event with $\pt>30~\GeV$ |
15 |
|
within $|\eta|<2.5$, out of which at least 1 is b-tagged based on |
16 |
< |
the SSV medium working point [CITE]. |
16 |
> |
the SSV medium working point. |
17 |
|
\item require moderate $\met>50~\GeV$ |
18 |
|
\end{itemize} |
19 |
|
|
20 |
< |
A benchmark signal sample is selected by tightening the \met\ and |
20 |
> |
Currently, we focus on the muon channel because it is cleaner (the QCD contribution is negligible) |
21 |
> |
and the triggers are simpler (we use single muon triggers, as opposed to electron + 3-jet triggers). |
22 |
> |
We will add the electron channel, time permitting. However, since this is a systematics-dominated |
23 |
> |
analysis, increasing the statistics by adding the electrons is not expected to significantly improve |
24 |
> |
the sensitivity, especialy because the electron selection efficiency is smaller and the systematic |
25 |
> |
uncertainty associated with the QCD background is larger. |
26 |
> |
|
27 |
> |
A benchmark signal region is selected by tightening the \met\ and |
28 |
|
adding an \mt\ requirement |
29 |
|
\begin{itemize} |
30 |
|
\item $\met>100~\GeV$ |
31 |
|
\item $\mt>150~\GeV$ |
32 |
|
\end{itemize} |
33 |
|
|
34 |
+ |
{\bf We have not looked at the data in the signal region after the first 1 fb$^{-1}$ of data.} |
35 |
+ |
|
36 |
|
\subsection{Corrections to Jets and \met} |
37 |
|
|
38 |
|
The official recommendations from the Jet/MET group are used for |
43 |
|
data (MC). In addition, these jet energy corrections are propagated to |
44 |
|
the \met\ calculation, following the official prescription for |
45 |
|
deriving the Type I corrections. It may be noted that events with |
46 |
< |
anomalous corrections are excluded from the sample since these |
46 |
> |
anomalous ``rho'' pile-up corrections are excluded from the sample since these |
47 |
|
correspond to events with unphysically large \met\ and \mt\ tail |
48 |
< |
signal region. An additional correction to remove |
48 |
> |
signal region (see Figure~\ref{fig:mtrhocomp}). An additional correction to remove |
49 |
|
the $\phi$-modulation observed in the \met\ is included, improving |
50 |
|
the agreement between the data and the MC, as shown in |
51 |
< |
Figure.~\ref{fig:metphicomp}. This correction has an effect on this analysis, |
51 |
> |
Figure~\ref{fig:metphicomp}. This correction has an effect on this analysis, |
52 |
|
since the azimuthal angle enters the \mt\ distribution. |
53 |
|
|
54 |
< |
\begin{figure}[tbh] |
54 |
> |
\clearpage |
55 |
> |
|
56 |
> |
\begin{figure}[!ht] |
57 |
|
\begin{center} |
58 |
|
\includegraphics[width=0.5\linewidth]{plots/mt_rho_comp.png} |
59 |
|
\caption{ \label{fig:mtrhocomp}%\protect |
68 |
|
\end{center} |
69 |
|
\end{figure} |
70 |
|
|
71 |
< |
\begin{figure}[hb] |
71 |
> |
\begin{figure}[!hb] |
72 |
|
\begin{center} |
73 |
|
\includegraphics[width=0.5\linewidth]{plots/metphi.pdf}% |
74 |
|
\includegraphics[width=0.5\linewidth]{plots/metphi_phicorr.pdf} |
79 |
|
\end{center} |
80 |
|
\end{figure} |
81 |
|
|
82 |
+ |
\clearpage |
83 |
+ |
|
84 |
|
\subsection{Branching Fraction Correction} |
85 |
|
|
86 |
|
The leptonic branching fraction used in some of the \ttbar\ MC samples |
87 |
< |
differs from the value listed in the PDG $(10.80 ± 0.09)\%$. |
87 |
> |
differs from the value listed in the PDG $(10.80 \pm 0.09)\%$. |
88 |
|
Table.~\ref{tab:wlepbf} summarizes the branching fractions used in |
89 |
|
the generation of the various \ttbar\ MC samples. |
90 |
|
For \ttbar\ samples with the incorrect leptonic branching fraction, event |