| 170 |
|
An additional source of concern is that the CMS Madgraph $t\bar{t}$ MC does |
| 171 |
|
not include effects of spin correlations between the two top quarks. |
| 172 |
|
We have studied this effect at the generator level using Alpgen. We find |
| 173 |
< |
that the bias is a the few percent level. |
| 173 |
> |
that the bias is at the few percent level. |
| 174 |
|
|
| 175 |
|
Based on the results of Table~\ref{tab:victorybad}, we conclude that the |
| 176 |
|
naive data driven background estimate based on $P_T{(\ell\ell)}$ needs to |
| 178 |
|
about this)} . The quoted |
| 179 |
|
uncertainty is based on the stability of the Monte Carlo tests under |
| 180 |
|
variations of event selections, choices of \met algorithm, etc. |
| 181 |
+ |
For example, we find that observed/predicted changes by roughly 0.1 |
| 182 |
+ |
for each 1.5\% change in the average \met response. |
| 183 |
|
|
| 184 |
|
|
| 185 |
|
|
| 219 |
|
are normalized to 30 pb$^{-1}$.} |
| 220 |
|
\begin{tabular}{|c||c|c||c|c|} |
| 221 |
|
\hline |
| 222 |
< |
SM & LM0 & BG Prediction & LM1 & BG Prediction \\ |
| 222 |
> |
SM & SM$+$LM0 & BG Prediction & Sm$+$LM1 & BG Prediction \\ |
| 223 |
|
Background & Contribution& Including LM0 & Contribution & Including LM1 \\ \hline |
| 224 |
< |
1.2 & 5.6 & 3.7 & 2.2 & 1.3 \\ |
| 224 |
> |
1.2 & 6.8 & 3.7 & 3.4 & 1.3 \\ |
| 225 |
|
\hline |
| 226 |
|
\end{tabular} |
| 227 |
|
\end{center} |
| 236 |
|
the fudge factor of 1.4 or watever because the method is not perfect.}} |
| 237 |
|
\begin{tabular}{|c||c|c||c|c|} |
| 238 |
|
\hline |
| 239 |
< |
SM & LM0 & BG Prediction & LM1 & BG Prediction \\ |
| 239 |
> |
SM & SM$+$LM0 & BG Prediction & Sm$+$LM1 & BG Prediction \\ |
| 240 |
|
Background & Contribution& Including LM0 & Contribution & Including LM1 \\ \hline |
| 241 |
< |
1.2 & 5.6 & 2.2 & 2.2 & 1.5 \\ |
| 241 |
> |
1.2 & 6.8 & 2.2 & 3.4 & 1.5 \\ |
| 242 |
|
\hline |
| 243 |
|
\end{tabular} |
| 244 |
|
\end{center} |
