| 12 |
|
Nevertheless, we can at least make some qualitative |
| 13 |
|
statements. |
| 14 |
|
|
| 15 |
< |
The systematic uncertainty on the letpon acceptance consists |
| 15 |
> |
The systematic uncertainty on the lepton acceptance consists |
| 16 |
|
of two parts: the trigger efficiency uncertainty and the |
| 17 |
|
ID and isolation of uncertainty. We discuss these in turn. |
| 18 |
|
|
| 23 |
|
We estimate the efficiency uncertainty to be a few percent, |
| 24 |
|
mostly in the low $P_T$ region. |
| 25 |
|
|
| 26 |
< |
The ID efficiency in MC is shown in {\color{red} Figures XX and |
| 27 |
< |
YY} for the leptons from $t \to W \to \ell$ and $t \to W \to \tau \to \ell$. |
| 28 |
< |
Tag and probe studies show that these are correct to about |
| 29 |
< |
{\color{red} xx\%. (We need to do tag-and-probe on the full sample, |
| 30 |
< |
see what we get, and write text accordingly).} |
| 31 |
< |
|
| 32 |
< |
The isolation efficiency depends on the jet activity in |
| 26 |
> |
\begin{figure}[tbh] |
| 27 |
> |
\begin{center} |
| 28 |
> |
\includegraphics[width=0.75\linewidth]{eff_11.png} |
| 29 |
> |
\caption{\label{fig:effttbar}\protect |
| 30 |
> |
Identification and isolation efficiencies for |
| 31 |
> |
leptons from $t \to W \to \ell$ and |
| 32 |
> |
$t \to W \to \tau \to \ell$ in |
| 33 |
> |
$t\bar{t}$ events.} |
| 34 |
> |
\end{center} |
| 35 |
> |
\end{figure} |
| 36 |
> |
|
| 37 |
> |
|
| 38 |
> |
\begin{table}[hbt] |
| 39 |
> |
\begin{center} |
| 40 |
> |
\caption{\label{tab:tagandprobe} Tag and probe results on $Z \to \ell \ell$ |
| 41 |
> |
on data and MC. We quote ID efficiency given isolation and |
| 42 |
> |
the isolation efficiency given ID.} |
| 43 |
> |
\begin{tabular}{|l||c|c|} |
| 44 |
> |
\hline |
| 45 |
> |
& Data T\&P & MC T\&P \\ \hline |
| 46 |
> |
$\epsilon(id|iso)$ electrons & $0.909\pm0.006$ & 0.926 \\ |
| 47 |
> |
$\epsilon(iso|id)$ electrons & $0.987\pm0.003$ & 0.985 \\ |
| 48 |
> |
$\epsilon(id|iso)$ muons & $0.955\pm0.003$ & 0.953 \\ |
| 49 |
> |
$\epsilon(iso|id)$ muons & $0.984\pm0.003$ & 0.981 \\ |
| 50 |
> |
\hline |
| 51 |
> |
\end{tabular} |
| 52 |
> |
\end{center} |
| 53 |
> |
\end{table} |
| 54 |
> |
|
| 55 |
> |
|
| 56 |
> |
The ID efficiencies in MC are shown in |
| 57 |
> |
Figures~\ref{fig:effttbar} |
| 58 |
> |
for the leptons from $t \to W \to \ell$ and $t \to W \to \tau \to \ell$. |
| 59 |
> |
Tag and probe studies show that these are correct to about 2\%, |
| 60 |
> |
see Table~\ref{tab:tagandprobe}. |
| 61 |
> |
Note that the isolation efficiency depends on the jet activity in |
| 62 |
|
the final state. For example, in MC we find that the |
| 63 |
|
lepton isolation efficiency differs by $\approx 4\%$ |
| 64 |
|
{\bf per lepton} between $Z$ events and $t\bar{t}$ events\cite{ref:top}. |
| 74 |
|
and two benchmark SUSY points. The uncertainties are calculated |
| 75 |
|
assuming a 5\% uncertainty to the hadronic energy scale in CMS. |
| 76 |
|
|
| 77 |
< |
{\color{red} For $t\bar{t}$ we find uncertainties of xx\% (baseline |
| 78 |
< |
selection) and yy\% (signal region D); for LM0 and LM1 we find |
| 79 |
< |
xx\% and yy\% respectively for signal region D.} |
| 77 |
> |
For $t\bar{t}$ we find uncertainties of 8\% (baseline |
| 78 |
> |
selection) and 30\% (signal region D); for LM0 and LM1 we find |
| 79 |
> |
14\% and 6\% respectively for signal region D. |
