| 11 |
|
before. Any deviation of the strength of these couplings from |
| 12 |
|
their standard model expectations manifests the new physics. |
| 13 |
|
|
| 14 |
< |
In addition, multi-lepton final states of \WZ\ production constitute |
| 15 |
< |
an important background to the search for new phenomena, |
| 16 |
< |
in particular Supersymmetry. A sound understanding of the \WZ\ |
| 14 |
> |
In addition, multi-lepton final states of \WZ\ production constitutes |
| 15 |
> |
an important background to potential new phenomena, |
| 16 |
> |
in particular Supersymmetry. A good understanding of the \WZ\ |
| 17 |
|
production-process is of paramount importance in the first phase |
| 18 |
|
of the LHC data-taking before any discovery can be claimed. |
| 19 |
|
At the same time, deviation of the \WZ\ production rate and |
| 23 |
|
In this note, we present results on the study of \WZ\ production |
| 24 |
|
based on the full simulation of the CMS detector. \WZ production in \pp\ |
| 25 |
|
collisions at the LHC mainly proceeds through quark annihilation into |
| 26 |
< |
an intermediate W boson, see Figure~\ref{fig:graph}. Cross section of |
| 26 |
> |
an intermediate W boson, see Fig.~\ref{fig:graph}. Cross section of |
| 27 |
|
about 31 pb and 19 pb are expected for the $W^+\Z$ and $W^-\Z$ final states, |
| 28 |
|
respectively~\cite{Haywood:1999qg}. There are four configuration of |
| 29 |
|
final state leptons considered in this analysis: $e^\pm \epem$, |
| 30 |
< |
$\mu^\pm \epem$, $\rm e^\pm \mu^+\mu^-$ and $\mu^\pm \mu^+\mu^-$. |
| 31 |
< |
Main instrumental background to all of the four signatures |
| 32 |
< |
is due to misidentified jets from associative production of jets and $\Z$ and |
| 33 |
< |
$W$ bosons and production of top quarks. The only physics background to |
| 34 |
< |
\WZ\ final state is $\Z\Z$ production with one of the leptons being |
| 35 |
< |
mis-reconstructed or lost. |
| 30 |
> |
$\mu^\pm \epem$, $\rm e^\pm \mu^+\mu^-$, and $\mu^\pm \mu^+\mu^-$. |
| 31 |
> |
Main instrumental background to all of the four signatures is due to |
| 32 |
> |
misidentified jets from top quark production and associative \Z or \W boson |
| 33 |
> |
and jets production. Next in significance is a background from |
| 34 |
> |
converted photons from $Z^0\gamma$ and $\W\gamma$ processes |
| 35 |
> |
that are identified as electrons. The only physics background to \WZ\ final state is $\Z\Z$ |
| 36 |
> |
production with one of the leptons being mis-reconstructed or lost. |
| 37 |
|
|
| 38 |
|
The structure of this note is as follows. We describe the signal |
| 39 |
|
and background modeling in Section~\ref{sec:gen}. The information |
| 40 |
|
on triggering and reconstruction of events is given in |
| 41 |
< |
Section~\ref{sec:eventReconstruction}. We present the analysis |
| 42 |
< |
strategy and estimate systematic uncertainties in Sections~\ref{sec:eventReconstruction} |
| 43 |
< |
and~\ref{sec:systematic}, respectively. The summary of the analysis |
| 44 |
< |
and results drawn with an emphasis on the \WZ\ observation |
| 45 |
< |
in early LHC data are given in Section~\ref{sec:results}. |
| 41 |
> |
Section~\ref{sec:eventReconstruction}. We present the methods of measuring |
| 42 |
> |
signal and background yields and estimate systematic uncertainties in |
| 43 |
> |
Sections~\ref{sec:SignalExt} and~\ref{sec:systematic}, respectively. |
| 44 |
> |
The summary of the analysis and results drawn with an emphasis on the |
| 45 |
> |
\WZ\ observation in early LHC data are given in Section~\ref{sec:results}. |
| 46 |
|
|
| 47 |
|
\begin{figure}[hbt] |
| 48 |
|
\begin{center} |
