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dilepton sample. The choice of signal region is driven by |
7 |
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three observations: |
8 |
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\begin{enumerate} |
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\item astrophisical evidence for dark matter suggests that |
9 |
> |
\item astrophysical evidence for dark matter suggests that |
10 |
|
we concentrate on the region of high \met; |
11 |
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\item new physics signals should have high $\sqrt{\hat{s}}$; |
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\item observable high cross section new physics signals |
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Following these observations, we add the following two requirements |
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to the preselection of Section~\ref{sec:eventSel}: |
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\begin{center} |
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SumJetPt$>$300 GeV and $\met/\sqrt{\rm SumJetPt} > 8.5$. |
20 |
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$\mathrm{SumJetPt}>300$~GeV and $\met/\sqrt{\rm SumJetPt} > 8.5$~GeV$^{1/2}$. |
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\end{center} |
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|
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\noindent This selection preserves about 1\% of the $t\bar{t}$ |
24 |
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signal, giving an expected total SM yield of 1.4 events in 35 pb$^{-1}$ |
25 |
< |
The expectations from the LMO and LM1 SUSY benchmark points are 6.5 and |
26 |
< |
2.6 events respectively. |
24 |
> |
signal. As shown in Table~\ref{tab:sigyield}, the expected total SM yield in 34.0~pb$^{-1}$ is 1.3 events, |
25 |
> |
while the expectations from the LMO and LM1 SUSY benchmark points are 8.6 and |
26 |
> |
3.6 events, respectively, computed at NLO. |
27 |
|
|
28 |
|
|
29 |
|
We cut on \met$/\sqrt{\rm SumJetPt}$ rather than \met |
30 |
< |
because the variables \met and \met$/\sqrt{\rm SumJetPt}$ are |
30 |
> |
because the variables SumJetPt and \met$/\sqrt{\rm SumJetPt}$ are |
31 |
|
largely uncorrelated for the dominant $t\bar{t}$ background. |
32 |
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This allows us to use a data driven ABCD method to estimate the |
33 |
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background (see Section~\ref{sec:abcd}). |
34 |
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|
35 |
+ |
|
36 |
+ |
|
37 |
+ |
|
38 |
+ |
\begin{table}[hbt] |
39 |
+ |
\begin{center} |
40 |
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\caption{\label{tab:sigyield} MC expected yields in the signal region for 34.0~pb$^{-1}$. |
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The errors are statistical only.} |
42 |
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\begin{tabular}{lcccc} |
43 |
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%%%official json v3, 33.96/pb, 38X MC (D6T for ttbar and DY) |
44 |
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\hline |
45 |
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Sample & $ee$ & $\mu\mu$ & $e\mu$ & tot \\ |
46 |
+ |
\hline |
47 |
+ |
$t\bar{t}\rightarrow \ell^{+}\ell^{-}$ & 0.28 $\pm$ 0.03 & 0.22 $\pm$ 0.03 & 0.57 $\pm$ 0.05 & 1.07 $\pm$ 0.06 \\ |
48 |
+ |
$t\bar{t}\rightarrow \mathrm{other}$ & 0.01 $\pm$ 0.01 & 0.00 $\pm$ 0.00 & 0.01 $\pm$ 0.01 & 0.02 $\pm$ 0.01 \\ |
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$Z^0 \rightarrow \ell^{+}\ell^{-}$ & 0.04 $\pm$ 0.04 & 0.04 $\pm$ 0.04 & 0.04 $\pm$ 0.04 & 0.12 $\pm$ 0.07 \\ |
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$W^{\pm}$ + jets & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 \\ |
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$W^+W^-$ & 0.00 $\pm$ 0.00 & 0.01 $\pm$ 0.00 & 0.02 $\pm$ 0.01 & 0.03 $\pm$ 0.01 \\ |
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+ |
$W^{\pm}Z^0$ & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 \\ |
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+ |
$Z^0Z^0$ & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 \\ |
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single top & 0.00 $\pm$ 0.00 & 0.00 $\pm$ 0.00 & 0.01 $\pm$ 0.00 & 0.01 $\pm$ 0.00 \\ |
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\hline |
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+ |
total SM MC & 0.34 $\pm$ 0.05 & 0.28 $\pm$ 0.05 & 0.65 $\pm$ 0.06 & 1.27 $\pm$ 0.10 \\ |
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\hline |
58 |
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data & 0 & 0 & 1 & 1 \\ |
59 |
+ |
\hline |
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% LM0 & 1.71 $\pm$ 0.10 & 2.05 $\pm$ 0.11 & 2.36 $\pm$ 0.12 & 6.12 $\pm$ 0.19 \\ |
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% LM1 & 0.87 $\pm$ 0.03 & 1.08 $\pm$ 0.03 & 0.55 $\pm$ 0.02 & 2.50 $\pm$ 0.04 \\ |
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%susy k-factors |
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LM0 & 2.37 $\pm$ 0.14 & 2.85 $\pm$ 0.15 & 3.41 $\pm$ 0.17 & 8.63 $\pm$ 0.27 \\ |
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LM1 & 1.24 $\pm$ 0.04 & 1.51 $\pm$ 0.04 & 0.81 $\pm$ 0.03 & 3.56 $\pm$ 0.06 \\ |
65 |
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|
66 |
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\hline |
67 |
+ |
\end{tabular} |
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\end{center} |
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\end{table} |