| 46 |
|
% Sophisticated fully ``data driven'' techniques are not really needed. |
| 47 |
|
|
| 48 |
|
One general point is that in order to minimize systematic uncertainties, the MC background |
| 49 |
< |
predictions are whenever possible normalized to the bulk of the $t\bar{t}$ data, i.e., events passing all of the |
| 49 |
> |
predictions are whenever possible normalized to the bulk of the $t\bar{t}$ data, i.e. events passing all of the |
| 50 |
|
requirements but with $M_T \approx 80$ GeV. |
| 51 |
|
This (mostly) removes uncertainties |
| 52 |
|
due to $\sigma(t\bar{t})$, lepton ID, trigger efficiency, luminosity, etc. |
| 78 |
|
$W +$ jets by the application of a b-veto. |
| 79 |
|
The equivalent ratio for top events ($R_{top}$) is tested in a sample of well |
| 80 |
|
identified $Z \to \ell \ell$ with one lepton added to the \met\ |
| 81 |
< |
calculation. |
| 81 |
> |
calculation. |
| 82 |
|
This sample is well suited to testing the resolution effects on |
| 83 |
|
the $M_T$ tail, since off-shell effects are eliminated by the $Z$-mass |
| 84 |
< |
requirement. |
| 84 |
> |
requirement. However, this test is unfortunately statistically |
| 85 |
> |
limited and its usefulness is limited to |
| 86 |
> |
event selections with modest \met\ |
| 87 |
> |
requirements. |
| 88 |
|
|
| 89 |
|
Note that the fact that the ratios are different for |
| 90 |
|
$t\bar{t}$/single top and $W +$ jets introduces a systematic |
