| 12 |
|
Nevertheless, we can make general statements about the |
| 13 |
|
systematic uncertainties, including quantitative |
| 14 |
|
estimates of the systematic uncertainties associated with |
| 15 |
< |
a few specific processes. |
| 15 |
> |
a few specific processes. Note that we have used Spring10 |
| 16 |
> |
MC for the studies of systematic uncertainties described in this section, |
| 17 |
> |
and we are currently checking if any of the reported values |
| 18 |
> |
change after switching to Fall10 MC. |
| 19 |
|
|
| 20 |
|
The systematic uncertainty on the lepton acceptance consists |
| 21 |
|
of two parts: the trigger efficiency uncertainty and the |
| 22 |
< |
ID and isolation of uncertainty. We discuss these in turn. |
| 22 |
> |
ID and isolation uncertainty. We discuss these in turn. |
| 23 |
|
|
| 24 |
|
The trigger efficiency |
| 25 |
|
for two leptons of $P_T>10$ GeV, with one lepton of |
| 26 |
|
$P_T>20$ GeV is very high, except in some corners |
| 27 |
< |
of phase space, see Section~\ref{sec:trgEff}. |
| 27 |
> |
of phase space, see Section~\ref{sec:trgeffsum}. |
| 28 |
|
We estimate the efficiency uncertainty to be a few percent, |
| 29 |
< |
mostly in the low $P_T$ region. |
| 29 |
> |
mostly in the low $P_T$ region. For $t\bar{t}$, LM0 and LM1 |
| 30 |
> |
we find trigger efficiency uncertainties of less than 1\%, evaluated |
| 31 |
> |
by taking the difference in yields in the signal region between |
| 32 |
> |
assuming 100\% trigger efficiency and using the trigger efficiency model. |
| 33 |
> |
% trigger efficiency uncertainties: ttbar 0.3%, LM0 0.6%, LM1 0.6% |
| 34 |
|
|
| 35 |
|
\begin{figure}[tbh] |
| 36 |
|
\begin{center} |
| 37 |
< |
\includegraphics[width=1.0\linewidth]{eff_35.png} |
| 37 |
> |
\includegraphics[width=1.0\linewidth]{ttdilD6T_eff_Dec02_38X.png} |
| 38 |
> |
\includegraphics[width=1.0\linewidth]{lm_eff_Dec02_38X.png} |
| 39 |
|
\caption{\label{fig:effttbar}\protect |
| 40 |
|
Identification and isolation efficiencies for |
| 41 |
|
leptons from $t \to W \to \ell$ and |
| 49 |
|
\begin{center} |
| 50 |
|
\caption{\label{tab:tagandprobe} Tag and probe results on $Z \to \ell \ell$ |
| 51 |
|
on data and MC. We quote ID efficiency given isolation and |
| 52 |
< |
the isolation efficiency given ID.} |
| 52 |
> |
the isolation efficiency given ID. {\bf \color{red} UPDATE WITH 38X }} |
| 53 |
|
\begin{tabular}{|l||c|c|} |
| 54 |
|
\hline |
| 55 |
|
& Data T\&P & MC T\&P \\ \hline |
| 72 |
|
the final state. For example, in MC we find that the |
| 73 |
|
lepton isolation efficiency differs by $\approx 4\%$ |
| 74 |
|
{\bf per lepton} between $Z$ events and $t\bar{t}$ events\cite{ref:top}. |
| 75 |
< |
\noindent {\bf This figure should be cut off at 100 GeV, and |
| 76 |
< |
the y-axis should be zero-suppressed} |
| 75 |
> |
{\bf \color{red} VERIFY THAT THESE VALUES ARE UNCHANGED IN 38X MC. } |
| 76 |
> |
%\noindent {\bf This figure should be cut off at 100 GeV, and |
| 77 |
> |
%the y-axis should be zero-suppressed} |
| 78 |
|
|
| 79 |
|
Another significant source of systematic uncertainty is |
| 80 |
|
associated with the jet and $\met$ energy scale. The impact |
| 87 |
|
and two benchmark SUSY points. The uncertainties are calculated |
| 88 |
|
assuming a 5\% uncertainty to the hadronic energy scale in CMS. |
| 89 |
|
|
| 90 |
< |
For $t\bar{t}$ we find uncertainties of 8\% (baseline |
| 91 |
< |
selection) and 30\% (signal region D); for LM0 and LM1 we find |
| 92 |
< |
14\% and 6\% respectively for signal region D. |
| 90 |
> |
For $t\bar{t}$ we find uncertainties of 3\% (baseline |
| 91 |
> |
selection) and 21\% (signal region D); for LM0 and LM1 we find |
| 92 |
> |
15\% and 6\% respectively for signal region D |
| 93 |
> |
{\bf \color{red} THESE VALUES HAVE BEEN RECALCULATED FOR 38X MC, AWAITING VERIFICATION} |
