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\label{sec:gen} |
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\subsection{Monte Carlo generators} |
| 4 |
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The signal and background samples for the full detector simulation |
| 5 |
< |
are generated with the leading order (LO) event generator |
| 5 |
> |
are generated with the leading order (LO) event generators |
| 6 |
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{\sl PYTHIA}~\cite{Sjostrand:2003wg}, {\sl ALPGEN} and {\sl COMPHEP}. |
| 7 |
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To accommodate next-to-leading (NLO) effects, constant $k$-factors are applied. |
| 8 |
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Additionally, the cross section calculator {\sl MCFM}~\cite{Campbell:2005} |
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\subsection{Signal and background Monte Carlo samples} |
| 63 |
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|
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The signal Monte Carlo sample is produced using {\sl PYTHIA} |
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< |
generator. The decay for the \W has been forced to $e\nu_e$ or |
| 66 |
< |
$\mu\nu_{mu}$ or $\tau\nu_{\tau}$ final state, while the \Z decays |
| 65 |
> |
generator. The decay for the \W has been forced to $e\nu_e$, |
| 66 |
> |
$\mu\nu_{\mu}$ or $\tau\nu_{\tau}$ final state, while the \Z decays |
| 67 |
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into electrons or muons only. |
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|
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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leptons. Moreover we will apply a cut on the invariant mass of the two |
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isolated leptons so most of the background that we have to study are:\\ |
| 78 |
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\begin{itemize} |
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< |
\item $W+jets$: $W$ boson will give us one isolated leptons. The probability that 2 additional jets will be misidentified as isolated lepton is very low and the criteria on the lepton invariant mass will definitely reduce such background. This channel is nevertheless useful to study other background for which data sample are not available such as $Wb\bar{b}$. The sample studied for this analysis, has been produced using ALPGEN generator per jet bin. |
| 79 |
> |
\item $W+jets$: $W$ boson will give us one isolated leptons. The probability that 2 additional jets will be misidentified as isolated lepton is very low and the criteria on the lepton invariant mass will definitely reduce such background. This channel is nevertheless useful to study other background for which data sample are not available such as $Wb\bar{b}$. The sample studied for this analysis, has been produced using ALPGEN generator per jet multiplicity bin. |
| 80 |
|
\item $Z + jets$: $Z$ boson is common between signal and background. The third isolated lepton can come from a misidentified lepton. The cross section of production of this channel is around 35 time greater than the signal.The sample studied for this analysis, has been produced using ALPGEN generator per jet bin. |
| 81 |
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\item $t\bar{t}$: top quark will decay to \W$b$ pair where each $W$ can decay via an isolated leptons. This leptons will have opposite charged. Even though combining the two leptons, we will not obtain a peak around the \Z mass, the cross section of this process is around 15 time the cross section of the signal. The sample studied for this analysis, has been produced using ALPGEN generator per jet bin. The third lepton will come from a semi leptonic decay of a $b$ quark which will be isolated. |
| 82 |
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\item $Z + b\bar{b}$: the presence of $Z$ boson will select such events. Moreover due to the semi leptonic decay of a $b$ quark, a third lepton can be easily identified and consider as isolated. The sample used has been produced by COMPHEP generator. |
| 83 |
< |
%\item $ZZ$: the inclusive cross section production is smaller than the signal studied but due to branching fraction and if we consider $Z\rightarrow b\bar{b}$ decay, some events can pass the analysis selection. This process has been produced using PYTHIA generator. |
| 83 |
> |
\item $ZZ$: the inclusive cross section production is smaller than the signal studied but due to branching fraction and if we consider $Z\rightarrow b\bar{b}$ decay, some events can pass the analysis selection. This process has be |
| 84 |
> |
en produced using PYTHIA generator. |
| 85 |
> |
\item $Z\gamma$: TO BE ADDED |
| 86 |
|
\end{itemize} |
| 87 |
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|
| 88 |
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All the different sample studied are part of the CSA07 production and |
| 89 |
< |
have been generated using $CMSSW\_1\_4_\_6$ and went through the full |
| 89 |
> |
have been generated using $\mathrm{CMSSW}\_1\_4_\_6$ and went through the full |
| 90 |
|
GEANT simulation of the CMS detector using the same release. The |
| 91 |
< |
digitization and reconstruction have been done using $CMSSW\_1\_6_\_7$ |
| 91 |
> |
digitization and reconstruction have been done using $\mathrm{CMSSW}\_1\_6_\_7$ |
| 92 |
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release with a misalignment/miscalibration of the detector expected |
| 93 |
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after 100~pb$^{-1}$ of data. All ALPGEN samples are mixed together in |
| 94 |
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``Chowder soup''. |
| 119 |
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$Z b\bar{b}$ & 830*0.173 (NLO) & 1.9M & /comphep-bbll/CMSSW$\_1\_6\_7$-CSA07-1198677426\\ \hline |
| 120 |
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Chowder & Event Weight & $\sim$ 21M & /CSA07AllEvents/\\ & & & CMSSW$\_1\_6\_7$-CSA07-Chowder-A1-PDAllEvents-ReReco |
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-100pb\\ \hline |
| 122 |
< |
%$ZZ\rightarrow ll l'l'$& 0.846 & |
| 123 |
< |
%\hline |
| 122 |
> |
$ZZ$ inclusif & 16.1 (NLO) & $\sim$ 140k & /ZZ$\_$incl/CMSSW$\_1\_6\_7$-CSA07-1194964234/RECO\\ \hline |
| 123 |
> |
$Z\gamma \rightarrow e^+e^-\gamma$ & 1.08 (NLO) & $\sim$125k &/Zeegamma/CMSSW$\_1\_6\_7$-CSA07-1198935518/RECO \\ \hline |
| 124 |
> |
$Z\gamma \rightarrow \mu^+\mu^-\gamma$ & 1.08 (NLO) & $\sim$ 93k & /Zmumugamma/CMSSW$\_1\_6\_7$-CSA07-1194806860/RECO\\ \hline |
| 125 |
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\end{tabular} |
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\label{tab:MC} |
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< |
\caption{Monte Carlo samples used in this analysis} |
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> |
\caption{Monte Carlo samples used in this analysis using 100pb$^{-1}$ scenario} |
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\end{table} |
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|
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