| 64 |
|
to predict the number of background events with |
| 65 |
|
$\HT > 300\GeV$ and $\MET > 275\GeV$ ($\HT > 600\GeV$ and $\MET > 200\GeV$). |
| 66 |
|
In practice, we apply two corrections to this prediction, following the same procedure as in Ref.~\cite{ref:ospaper}. |
| 67 |
< |
The first correction is $K_{50}=1.5 \pm 0.3$ ($1.3 \pm 0.2$) for the high \MET\ (high \Ht) signal region. |
| 68 |
< |
The second correction factor is $K_C = 1.5 \pm 0.5$ ($1.3 \pm 0.4$) for the |
| 67 |
> |
The first correction accounts for the fact that we require \met\ $>$ 50\GeV in the preselection |
| 68 |
> |
but there is no corresponding requirement on \ptll; this correction |
| 69 |
> |
is $K_{50}=1.5 \pm 0.3$ ($1.3 \pm 0.2$) for the high \MET\ (high \Ht) signal region. |
| 70 |
> |
The second correction factor accounts for the $W$ polarization in \ttbar\ events, as well |
| 71 |
> |
as detector effects such as hadronic energy scale; this correction is $K_C = 1.5 \pm 0.5$ ($1.3 \pm 0.4$) for the |
| 72 |
|
high \MET (high \Ht) signal region. |
| 73 |
|
|
| 74 |
|
Our third background estimation method is based on the fact that many models of new physics |
| 75 |
|
produce an excess of SF with respect to OF lepton pairs, while for the \ttbar\ background the |
| 76 |
< |
rates of SF and OF lepton pairs are the same. Hence we make use of the OF subtraction technique |
| 74 |
< |
discussed in Sec.~\ref{sec:fit} in which we performed a shape analysis of the dilepton mass distribution. |
| 76 |
> |
rates of SF and OF lepton pairs are the same, as discussed in Sec.~\ref{sec:fit}. |
| 77 |
|
Here we perform a counting experiment, by quantifying the excess of SF vs. OF pairs using the |
| 78 |
|
quantity |
| 79 |
|
|
