12 |
|
the jet energy scale (30\%, see Section~\ref{sec:systematics}), |
13 |
|
the luminosity (10\%), and the lepton/trigger |
14 |
|
efficiency (10\%)\footnote{Other uncertainties associated with |
15 |
< |
the modeling of $t\bar{t}$ in MadGraph have not been evaluated.}. |
15 |
> |
the modeling of $t\bar{t}$ in MadGraph have not been evaluated. |
16 |
> |
The uncertainty on $pp \to \sigma(t\bar{t})$ is also not included.}. |
17 |
|
The data driven background predictions from the ABCD method |
18 |
|
and the $P_T(\ell\ell)$ method are 1.5 $\pm$ 0.9 and |
19 |
|
$2.5 \pm 2.2$ events, respectively. |
22 |
|
and with the observation of one event in the signal region. |
23 |
|
We calculate a Bayesian 95\% CL upper limit\cite{ref:bayes.f} |
24 |
|
on the number of non SM events in the signal region to be 4.1. |
25 |
< |
This was calculated using a background prediction of $N_{BG}=1.4 \pm 1.0$ |
25 |
> |
This was calculated using a background prediction of $N_{BG}=1.4 \pm 1.1$ |
26 |
|
events. The upper limit is not very sensitive to the choice of |
27 |
|
$N_{BG}$ and its uncertainty. |
28 |
|
|
33 |
|
are from energy scale (Section~\ref{sec:systematics}), luminosity, |
34 |
|
and lepton efficiency. |
35 |
|
|
36 |
< |
In Figures XX and YY we provide the response functions for the |
37 |
< |
SumJetPt and \met/$\sqrt{\rm SumJetPt}$ cuts used in our analysis, |
38 |
< |
{\em i.e.} the efficiencies of the experimental cuts as a function of |
39 |
< |
the true quantities. Using this information as well as the kinematical |
36 |
> |
In Figure~\ref{fig:response} we provide the response functions for the |
37 |
> |
SumJetPt and \met/$\sqrt{\rm SumJetPt}$ in MC, as well as the |
38 |
> |
efficiency for the cuts on these quantities used in defining the |
39 |
> |
signal region. |
40 |
> |
% (SumJetPt $>$ 300 GeV and \met/$\sqrt{\rm SumJetPt} > 8.5$ |
41 |
> |
% Gev$^{\frac{1}{2}}$). |
42 |
> |
We find that the average SumJetPt response |
43 |
> |
in the Monte Carlo |
44 |
> |
is very close to one, with an RMS of order 10\%; |
45 |
> |
the |
46 |
> |
response of \met/$\sqrt{\rm SumJetPt}$ is approximately 0.94 with an |
47 |
> |
RMS of 14\%. |
48 |
> |
|
49 |
> |
Using this information as well as the kinematical |
50 |
|
cuts described in Section~\ref{sec:eventSel} and the lepton efficiencies |
51 |
|
of Figures~\ref{fig:effttbar}, one should be able to confront |
52 |
|
any existing or future model via a relatively simple generator |
53 |
|
level study by comparing the expected number of events in 35 pb$^{-1}$ |
54 |
< |
with our upper limit of 4.1 events. |
54 |
> |
with our upper limit of 4.1 events. |
55 |
> |
|
56 |
> |
\begin{figure}[tbh] |
57 |
> |
\begin{center} |
58 |
> |
\includegraphics[width=\linewidth]{selectionEff.png} |
59 |
> |
\caption{\label{fig:response} Left plots: the efficiencies |
60 |
> |
as a function of the true quantities for the SumJetPt (top) and |
61 |
> |
tcMET/$\sqrt{\rm SumJetPt}$ (bottom) requirements for the signal |
62 |
> |
region as a function of their true values. The value of the |
63 |
> |
cuts is indicated by the vertical line. |
64 |
> |
Right plots: The average response and its RMS for the SumJetPt |
65 |
> |
(top) and tcMET/$\sqrt{\rm SumJetPt}$ (bottom) measurements. |
66 |
> |
The response is defined as the ratio of the reconstructed quantity |
67 |
> |
to the true quantity in MC. These plots are done using the LM0 |
68 |
> |
Monte Carlo, but they are not expected to depend strongly on |
69 |
> |
the underlying physics.} |
70 |
> |
\end{center} |
71 |
> |
\end{figure} |