| 17 |
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|
| 18 |
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\item \textbf{Why the PDF systematics are only considered for significance (should be the opposite)?}\\ |
| 19 |
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The PDF systematics should indeed also be considered for the cross section measurement and we added |
| 20 |
< |
them to the list of uncertainties affecting the cross section. They are however also relevant for the |
| 21 |
< |
expected significance. The estimated significance depends on the number of expected |
| 22 |
< |
signal events, which depend on the WZ cross section. Of course the significance we will one day |
| 23 |
< |
estimate on real data does not depend on this. The PDF uncertainties on the cross section have been |
| 24 |
< |
determined at the PTDR time by varying the PDF within the range allowed by the errors of the PDF |
| 20 |
> |
them to the list of uncertainties affecting the cross section. It affects it through the signal acceptance |
| 21 |
> |
which may vary for different PDF assumptions. PDF uncertainties are not relevant for the signal significance |
| 22 |
> |
we will quote one day on real data, but they are however relevant for the expected significance we quote |
| 23 |
> |
in this analysis. The estimated significance depends on the number of expected |
| 24 |
> |
signal events, which depend on the WZ cross section. The PDF uncertainties on the cross section have |
| 25 |
> |
been determined at the PTDR time by varying the PDF within the range allowed by the errors of the PDF |
| 26 |
|
fit (to HERA data). |
| 27 |
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|
| 27 |
– |
|
| 28 |
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\item \textbf{What are the PDF systematics for ZZ background? [mainly for 3mu channel]}\\ |
| 29 |
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We are using the systematics derived in note AN-2006/055 which are 6.4\%. |
| 30 |
|
|
| 31 |
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\item \textbf{Does the cross section used for signal include the gamma*?}\\ |
| 32 |
< |
The response is complex: the signal simulated by Pythia do not include |
| 33 |
< |
the gamma* but the k-factor which has been used to go from LO to |
| 34 |
< |
NLO as been computed via MC@NLO including gamma* (NLO with gamma*/LO with gamma*). |
| 32 |
> |
The response is complex: the signal simulated by Pythia does not include |
| 33 |
> |
the $\gamma^*$ but the k-factor which has been used to go from LO to |
| 34 |
> |
NLO has been computed via MCFM including $\gamma^*$ (NLO with $\gamma^*$ / LO with $\gamma^*$). |
| 35 |
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|
| 36 |
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\item \textbf{Does reconstruction efficiency (Z) depend on pt(Z) ?}\\ |
| 37 |
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Indeed a bit, so we have applied a k-factor dependant on pt(Z). |
| 42 |
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|
| 43 |
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\item \textbf{Can you confirm that gamma* is included in Zbb and ZZ Monte Carlo and that cross section are correctly calculated?}\\ |
| 44 |
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For $ZZ$, the production as been done with a m(gamma*) $>$ 12 GeV and for |
| 45 |
< |
$Zbbar{b}$ m(gamma*)$>$40 GeV. Please see the webpage: |
| 45 |
> |
$Zb\bar{b}$ m(gamma*)$>$40 GeV. Please see the webpage: |
| 46 |
|
$http://cmsdoc.cern.ch/\sim anikiten/cms\-higgs/sm\_cross\-sections.txt$ for |
| 47 |
|
$ZZ$ and the CMSNote AN 2008/020 for $Zb\bar{b}$ background. |
| 48 |
|
|
| 49 |
|
\item \textbf{Can you confirm that gamma* is included in $Z+jets$ samples?}\\ |
| 50 |
< |
Yes the production has been done within: 40 GeV<M(z/gamma*)<200GeV |
| 50 |
> |
Yes the production has been done within: 40 GeV$<$M(z/gamma*)$<$200GeV |
| 51 |
|
please see the note:IN 2007/031. |
| 52 |
|
|
| 53 |
< |
\item \textbf{Can you improve signal over background by adding a cut on MET?} |
| 53 |
> |
\item \textbf{Can you improve signal over background by adding a cut on MET?}\\ |
| 54 |
|
We have studied the possibility but we obtain a better significance by |
| 55 |
|
applying a cut on transverse mass of W candidate ($>$50 GeV). In the |
| 56 |
|
analysis we are now considering such cuts. The studies of the |
| 57 |
< |
different angle proposed have been also performed but the transverse |
| 58 |
< |
mass remain the best variable. DO YOU HAVE PLOTS? |
| 57 |
> |
different angle proposed have been also performed, see figures~\ref{fig:metcos}, |
| 58 |
> |
\ref{fig:metsin} and \ref{fig:sig_metcos}, but the transverse |
| 59 |
> |
mass remain the best variable. |
| 60 |
|
|
| 61 |
< |
\item \textbf{Produce Event yield table and mass plot with MET$>$20} |
| 62 |
< |
We have update the note but with a transverse mass cut at 50 GeV. |
| 61 |
> |
\begin{figure}[!bp] |
| 62 |
> |
\begin{center} |
| 63 |
> |
\scalebox{0.6}{\includegraphics{backupfigs/metcos.eps}} |
| 64 |
> |
\caption{ |
| 65 |
> |
Longitudinal component of the MET vector with respect to the direction of the |
| 66 |
> |
lepton associated to the W-decay. |
| 67 |
> |
} |
| 68 |
> |
\label{fig:metcos} |
| 69 |
> |
\end{center} |
| 70 |
> |
\end{figure} |
| 71 |
> |
|
| 72 |
> |
\begin{figure}[p] |
| 73 |
> |
\begin{center} |
| 74 |
> |
\scalebox{0.6}{\includegraphics{backupfigs/metsin.eps}} |
| 75 |
> |
\caption{ |
| 76 |
> |
Transverse component of the MET vector with respect to the direction of the |
| 77 |
> |
lepton associated to the W-decay. |
| 78 |
> |
} |
| 79 |
> |
\label{fig:metcos} |
| 80 |
> |
|
| 81 |
> |
\scalebox{0.6}{\includegraphics{backupfigs/sig_metsin.eps}} |
| 82 |
> |
\caption{ |
| 83 |
> |
Signal significance as a function of a cut on the transverse component of the MET |
| 84 |
> |
vector with respect to the direction of the lepton associated to the W-decay. |
| 85 |
> |
} |
| 86 |
> |
\label{fig:sig_metsin} |
| 87 |
> |
\end{center} |
| 88 |
> |
\end{figure} |
| 89 |
> |
|
| 90 |
> |
|
| 91 |
> |
|
| 92 |
> |
\item \textbf{Produce Event yield table and mass plot with MET$>$20}\\ |
| 93 |
> |
We have updated the note but with a transverse mass cut at 50 GeV. |
| 94 |
|
|
| 95 |
|
\item \textbf{Redo all plots with 300pb$^{-1}$, produce event yields table with errors}\\ |
| 96 |
|
Done in the note |
| 110 |
|
|
| 111 |
|
|
| 112 |
|
\item \textbf{Please developp the way systematics will be evaluated}\\ |
| 113 |
< |
We have added:\\ {\it Trigger}: [...] From the current analysis of |
| 114 |
< |
$Z\rightarrow l^+l^-$ in CMS~\ref{Zmumu}~\ref{Zee}, the number of Z |
| 113 |
> |
We have added: (Bibliography is done in the note)\\ |
| 114 |
> |
\begin{itemize} |
| 115 |
> |
\item {\it Trigger}: [...] From the current analysis of |
| 116 |
> |
$Z\rightarrow l^+l^-$ in CMS~\cite{Zmumu}~\cite{Zee}, the number of Z |
| 117 |
|
events is estimated of the order of 50k per 100pb$^{-1}$ of data |
| 118 |
|
analysed. To determine the trigger efficiency ``tag-and-probe'' |
| 119 |
< |
method~\ref{TP} will be used.\\ {\it Reconstruction}: The |
| 119 |
> |
method~\cite{TP} will be used. |
| 120 |
> |
\item {\it Reconstruction}: The |
| 121 |
|
mismeasurement of the charge is of the order of 2\% in CMSSW\_1\_6\_7 |
| 122 |
|
release for electron. The estimation of the fraction with data will be |
| 123 |
|
done by looking at the Z peak without opposite charge |
| 124 |
|
requirement. Then number of events within the Z mass windows asking |
| 125 |
|
for two leptons of same sign will give us a estimate of the fraction |
| 126 |
< |
of mismeasure sign leptons.\\ {\it Lepton identification}:The letpons |
| 126 |
> |
of mismeasure sign leptons. |
| 127 |
> |
\item {\it Lepton identification}:The leptons |
| 128 |
|
scale will be established using the Z mass peak. |
| 129 |
< |
|
| 129 |
> |
\item {\it PDF uncertainties}: see response about PDF's above |
| 130 |
> |
\end{itemize} |
| 131 |
|
|
| 132 |
|
\item \textbf{Write a section on the pseudo-experiment and start the plot at 100pb$^-1$}\\ |
| 133 |
|
To estimate the amount of data necessary to claim an evidence or observation |
| 134 |
|
of the WZ signal, we perform 200,000 pseudoexperiements for data for a given |
| 135 |
|
value of data that is varied from 40 to 500 pb$^{-1}$. For each pseudoexperiment |
| 136 |
< |
we use Poission statistics to estimate the expected number of events for |
| 136 |
> |
we use Poisson statistics to estimate the expected number of events for |
| 137 |
|
signal and for each background sources separately, for each signature channel. |
| 138 |
|
The mean of the expected number of events is varied using Gaussian statistic |
| 139 |
|
using systematic uncertainties given in Table~\ref{tab:FullSys}. The significance of the |
| 146 |
|
events observed in the four signatures of the analysis, respectively. By summing |
| 147 |
|
signal and background together, we assume no correlation between the signature |
| 148 |
|
channels, which result in a conservative estimation of the sensitivity reach. |
| 149 |
< |
Obtained $S_L$ distribution is fit with Gaussian function to obtain the mean |
| 149 |
> |
The obtained $S_L$ distribution is fitted with Gaussian function to obtain the mean |
| 150 |
|
and resolution width, which would correspond to the most probable value of $S_L$ |
| 151 |
|
and its uncertainty for a given value of integrated luminosity. The 68\% and 95\% |
| 152 |
|
CL bands are $\pm 1\sigma$ and $\pm 1.96\sigma$ bands around the mean value |
