--- ttbar/p20_taujets_note/b_and_tau.tex 2011/05/18 21:30:39 1.1 +++ ttbar/p20_taujets_note/b_and_tau.tex 2011/06/01 01:20:54 1.2 @@ -3,17 +3,20 @@ In the next step we applied the requirements of tight $\tau$- and $b$-tagging. Table \ref{cap:btaggingandtau} shows the selection criteria that -we applied to data and MC. The b-tag operating point used was TIGHT, which corresponds -to NNbtag $>$ 0.775. We chose the $\tau$ with the highest $NN_{\tau}$ as \textit{the} $\tau$ candidate. +we applied to data and MC. The $b$-tag operating point used was TIGHT, which corresponds +to NNbtag $>$ 0.775. In there are more than 1 tau candidate in the event then we +choose the one with the highets $NN_{\tau}$ as the only one. Also we apply a tau-jet matching +condition. A tau candidate is only used in the measurement if the separation between it +and a jet is $\Delta R = \sqrt{{(\Delta \eta})^{2} + {(\Delta \phi})^{2}} > 0.5$. At this stage of the analysis we separated the events dataset we deal with into parts, -according to which type of $\tau$ the candidate with highest NN belongs. +according to which type of $\tau$ the candidate with highest $NN_{\tau}$ belongs. This was done primarily to separate the type 3 tau events (which are expected to have much higher fake rate and thus weaker $\ttbar$ cross section result) from the type 2 events. The separate measurement channels were later combined to get the final result (Section \ref{sub:xsect}). In principle, types 1 and 2 should be separated as well but as there exists a considerable cross-migration between them \cite{tau-id} and type 1 is a small fraction of -the total (10\% of type 1, 54.5\% of type 2 and 35.5\% of type 3), they were taken togetther in this analysis. +the total (10\% of type 1, 54.5\% of type 2 and 35.5\% of type 3), they were taken together in this analysis. The topological NN used to enhance the signal content is described in section \ref{sub:NN-variables} . %Table \ref{b and tau type 3} shows the same efficiencies for @@ -22,11 +25,12 @@ The topological NN used to enhance the s At this point, we used these ID algorithms to define 3 mutually exclusive and -exhastive subsamples out of the original preselected data sample: +exhastive subsamples out of the preselected data sample: \begin{itemize} -\item The {}``non-$b$ veto'' or {}``signal'' sample - the $\tau$ candidate has $NN_{\tau}>0.90$ ($NN_{\tau}$ denotes the NN cut commonly applied to all taus) -for taus types 1 and 2 and $NN(\tau)>0.95$ for taus type 3, and at least one NN b-tag (as in Table \ref{cap:btaggingandtau}). +\item The {}``non-$b$-tag'' or {}``signal'' sample - The $\tau$ candidate has $NN_{\tau}>0.90$ +($NN_{\tau}$ denotes the NN cut commonly applied to all taus) +for taus types 1 and 2 and $NN_{\tau}>0.95$ for taus type 3, and at least one NN b-tag (as in Table \ref{cap:btaggingandtau}). These $NN(\tau)$ cuts were chosen based on previous studies involving hadronic decays of taus \cite{tes,higgs_tau}. This is the sample used to extract the cross section. Jets matched to $\tau$ candidates are not $b$-tagged, althought they still count as jets. @@ -34,23 +38,22 @@ althought they still count as jets. $0.3$ 0.9 only -to type 2 taus since these are more likely to be faked by electrons. The cut NNelec $>$ 0.9 was chosen in -order to match the lowest cut of $NN_{\tau}$ $>$ 0.9 applied to type 2 taus (Section \ref{sub:Results-of-the}). +One extra cut applied along with the $NN_{\tau}$ +cut described above was the so called NNelec cut. It is meant to be applied to Type 2 taus only in order +to reduce the probability of having these being faked by electrons. We chose a non-optimized cut of NNelec $>$ 0.9. As both b and $\tau$ ID is the step immediately after the preselection, the number of events available is -2800000 million events. As explained above 1400000 events were used for taus type 1 and 2 NN training -and 600000 for type 3 taus NN training. Thus, there are 1400000 events available in each sample for the -measurement in the case of types 1 and 2 and 2200000 in the case of type 3. Details on NN training are given +2800000 events. As explained above 1400000 events were used for taus of Type 1 and 2 NN training +and 600000 for Type 3 taus NN training. Thus, there are 1400000 events available in each sample for the +measurement in the case of Types 1 and 2 and 2200000 in the case of Type 3. Details of NN training are given in Section \ref{sub:NN-variables}. @@ -66,7 +69,7 @@ know whether this sample is totally QCD Numbers showing the composition of such sample are shown on Tables \ref{loosetight1_2} and \ref{loosetight_3} with their respective statistical uncertainties. From the $t\bar{t}$ content in each case we are able estimate the signal contamination in the loose-tight sample. Such contaminations are 5.4\% -and 3.0\% for taus type 1 and 2 and type 3 respectively when a cross section of 7.46 pb is assumed +and 3.0\% for taus of Type 1 and 2 and Type 3 respectively when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed (Section \ref{sub:mcsample}). Likewise we see that electroweak contaminations are 2.2\% and 0.9\%. As this is the sample used to model the QCD background both signal and electroweak contaminations were taken into account when measuring the @@ -96,8 +99,8 @@ cross section in Section \ref{sub:xsect} \caption{$b$-tagging and $\tau$ ID. In the MC, we use the $b$-tagging certified parameterization rather than actual $b$-tagging, that is, we applied the $b$-tagging weight. We also used the triggering weight -as computed by the trigger efficiency parameterization as well as luminosity profile and $PV_Z$ reweighting weights. $ -mcweight$ is the MC normalization factors (to luminosity), which are different for MC +as computed by the trigger efficiency parameterization as well as luminosity profile, $PV_Z$ reweighting +and $WZPt$ reweighting weights. $mcweight$ is the MC normalization factor (to luminosity), which is different for MC samples with different parton multiplicities in ALPGEN MC samples.}%\end{ruledtabular} \label{cap:btaggingandtau} \end{table} @@ -136,31 +139,31 @@ $Wcc+jets\rightarrow$ $l\nu+cc+jets$& $Wjj+jets\rightarrow$ $l\nu+jj+jets$& & 5.66 $\pm$ 0.11 \\ -$Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& & 0.93 $\pm$ 0.08\\ -$Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& & 0.51 $\pm$ 0.04\\ -$Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& & 1.07 $\pm$ 0.10 \\ -$Zbb+jets\rightarrow$ $ee+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $ee+bb+jets$& & 0.03 $\pm$ 0.01\\ -$Zcc+jets\rightarrow$ $ee+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $ee+cc+jets$& & 0.00 $\pm$ 0.00\\ -$Zjj+jets\rightarrow$ $ee+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $ee+jj+jets$& & 0.02 $\pm$ 0.01 \\ -$Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& & 0.07 $\pm$ 0.02\\ -$Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& & 0.02 $\pm$ 0.01\\ -$Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& & 0.01 $\pm$ 0.01 \\ $Zbb+jets\rightarrow$ $\nu\nu+bb+jets$& @@ -173,8 +176,8 @@ $Zjj+jets\rightarrow$ $\nu\nu+jj+jets$& & 0.04 $\pm$ 0.01\\ \hline \end{tabular} -\caption{Final number of events in each channel for taus types 1 and 2 $\tau$ after b-tagging, $\tau$ ID and trigger -in the signal sample when the assumed cross section is 7.46 pb. An estimate of QCD background is not included.} +\caption{Final number of events in each channel for taus of Types 1 and 2 $\tau$ after b-tagging, $\tau$ ID and trigger +in the signal sample when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed. An estimate of QCD background is not included.} %\end{ruledtabular} \label{b_and_tau_type1_2} \end{table} @@ -213,31 +216,31 @@ $Wcc+jets\rightarrow$ $l\nu+cc+jets$& $Wjj+jets\rightarrow$ $l\nu+jj+jets$& & 4.08 $\pm$ 0.11\\ -$Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& & 0.74 $\pm$ 0.07\\ -$Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& & 0.41 $\pm$ 0.03\\ -$Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& & 0.80 $\pm$ 0.10 \\ -$Zbb+jets\rightarrow$ $ee+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $ee+bb+jets$& & 0.00 $\pm$ 0.00\\ -$Zcc+jets\rightarrow$ $ee+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $ee+cc+jets$& & 0.01 $\pm$ 0.01\\ -$Zjj+jets\rightarrow$ $ee+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $ee+jj+jets$& & 0.01 $\pm$ 0.01 \\ -$Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& & 0.04 $\pm$ 0.02\\ -$Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& & 0.01 $\pm$ 0.01\\ -$Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& & 0.00 $\pm$ 0.00 \\ $Zbb+jets\rightarrow$ $\nu\nu+bb+jets$& @@ -250,8 +253,8 @@ $Zjj+jets\rightarrow$ $\nu\nu+jj+jets$& & 0.06 $\pm$ 0.01 \\ \hline \end{tabular} -\caption{Final number of events in each channel for taus type 3 $\tau$ After b-tagging, $\tau$ ID and trigger -in the signal sample when the assumed cross section is 7.46 pb. An estimate of QCD background is not included.}%\end{ruledtabular} +\caption{Final number of events in each channel for taus Type 3 $\tau$ After b-tagging, $\tau$ ID and trigger +in the signal sample when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed. An estimate of QCD background is not included.}%\end{ruledtabular} \label{b_and_tau_type_3} \end{table} @@ -288,31 +291,31 @@ $Wcc+jets\rightarrow$ $l\nu+cc+jets$& $Wjj+jets\rightarrow$ $l\nu+jj+jets$& & 169.95 $\pm$ 2.68\\ -$Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& & 1.30 $\pm$ 0.11\\ -$Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& & 3.15 $\pm$ 0.20\\ -$Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& & 16.86 $\pm$ 1.14 \\ -$Zbb+jets\rightarrow$ $ee+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $ee+bb+jets$& & 0.02 $\pm$ 0.01\\ -$Zcc+jets\rightarrow$ $ee+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $ee+cc+jets$& & 0.00 $\pm$ 0.00\\ -$Zjj+jets\rightarrow$ $ee+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $ee+jj+jets$& & 0.74 $\pm$ 0.33 \\ -$Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& & 0.08 $\pm$ 0.02\\ -$Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& & 0.07 $\pm$ 0.03\\ -$Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& & 0.38 $\pm$ 0.22 \\ $Zbb+jets\rightarrow$ $\nu\nu+bb+jets$& @@ -325,7 +328,7 @@ $Zjj+jets\rightarrow$ $\nu\nu+jj+jets$& & 1.36 $\pm$ 0.49 \\ \hline \end{tabular} -\caption{$b$-veto data set composition for types 1 and 2 $\tau$ when the assumed cross section is 7.46 pb.}%\end{ruledtabular} +\caption{$b$-veto data set composition for Types 1 and 2 $\tau$ when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed.}%\end{ruledtabular} \label{bveto_type1_2} \end{table} @@ -362,31 +365,31 @@ $Wcc+jets\rightarrow$ $l\nu+cc+jets$& $Wjj+jets\rightarrow$ $l\nu+jj+jets$& & 126.41 $\pm$ 2.60 \\ -$Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& & 0.92 $\pm$ 0.09\\ -$Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& & 2.86 $\pm$ 0.20\\ -$Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& & 14.53 $\pm$ 1.15 \\ -$Zbb+jets\rightarrow$ $ee+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $ee+bb+jets$& & 0.00 $\pm$ 0.00\\ -$Zcc+jets\rightarrow$ $ee+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $ee+cc+jets$& & 0.08 $\pm$ 0.04\\ -$Zjj+jets\rightarrow$ $ee+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $ee+jj+jets$& & 0.31 $\pm$ 0.18 \\ -$Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& & 0.04 $\pm$ 0.02\\ -$Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& & 0.05 $\pm$ 0.02\\ -$Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& & 0.05 $\pm$ 0.04 \\ $Zbb+jets\rightarrow$ $\nu\nu+bb+jets$& @@ -400,7 +403,7 @@ $Zjj+jets\rightarrow$ $\nu\nu+jj+jets$& 2.31 $\pm$ 0.46 \\ \hline \end{tabular} %\end{ruledtabular} -\caption{$b$-veto data set composition for type 3 $\tau$ when the assumed cross section is 7.46 pb.} +\caption{$b$-veto data set composition for Type 3 $\tau$ when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed.} \label{b_veto_type_3} \end{table} @@ -436,31 +439,31 @@ $Wcc+jets\rightarrow$ $l\nu+cc+jets$& $Wjj+jets\rightarrow$ $l\nu+jj+jets$& & 11.34 $\pm$ 0.26\\ -$Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& & 0.50 $\pm$ 0.06\\ -$Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& & 0.58 $\pm$ 0.06\\ -$Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& & 1.10 $\pm$ 0.13 \\ -$Zbb+jets\rightarrow$ $ee+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $ee+bb+jets$& & 0.01 $\pm$ 0.01\\ -$Zcc+jets\rightarrow$ $ee+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $ee+cc+jets$& & 0.01 $\pm$ 0.01\\ -$Zjj+jets\rightarrow$ $ee+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $ee+jj+jets$& & 0.00 $\pm$ 0.00 \\ -$Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& & 0.03 $\pm$ 0.01\\ -$Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& & 0.04 $\pm$ 0.01\\ -$Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& & 0.02 $\pm$ 0.01 \\ $Zbb+jets\rightarrow$ $\nu\nu+bb+jets$& @@ -473,7 +476,7 @@ $Zjj+jets\rightarrow$ $\nu\nu+jj+jets$& & 0.36 $\pm$ 0.04 \\ \hline \end{tabular} -\caption{loose-tight data set composition for types 1 and 2 $\tau$ when the assumed cross section is 7.46 pb.}%\end{ruledtabular} +\caption{loose-tight data set composition for Types 1 and 2 $\tau$ when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed.}%\end{ruledtabular} \label{loosetight1_2} \end{table} @@ -511,31 +514,31 @@ $Wcc+jets\rightarrow$ $l\nu+cc+jets$& $Wjj+jets\rightarrow$ $l\nu+jj+jets$& & 16.32 $\pm$ 0.30 \\ -$Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\tau\tau+bb+jets$& & 0.52 $\pm$ 0.05\\ -$Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\tau\tau+cc+jets$& & 0.46 $\pm$ 0.04\\ -$Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\tau\tau+jj+jets$& & 1.16 $\pm$ 0.12 \\ -$Zbb+jets\rightarrow$ $ee+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $ee+bb+jets$& & 0.00 $\pm$ 0.00\\ -$Zcc+jets\rightarrow$ $ee+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $ee+cc+jets$& & 0.00 $\pm$ 0.00\\ -$Zjj+jets\rightarrow$ $ee+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $ee+jj+jets$& & 0.01 $\pm$ 0.01 \\ -$Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& +$\gamma Zbb+jets\rightarrow$ $\mu\mu+bb+jets$& & 0.06 $\pm$ 0.01\\ -$Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& +$\gamma Zcc+jets\rightarrow$ $\mu\mu+cc+jets$& & 0.07 $\pm$ 0.01\\ -$Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& +$\gamma Zjj+jets\rightarrow$ $\mu\mu+jj+jets$& & 0.11 $\pm$ 0.02 \\ $Zbb+jets\rightarrow$ $\nu\nu+bb+jets$& @@ -549,7 +552,7 @@ $Zjj+jets\rightarrow$ $\nu\nu+jj+jets$& 1.28 $\pm$ 0.08 \\ \hline \end{tabular} %\end{ruledtabular} -\caption{loose-tight data set composition for type 3 $\tau$ when the assumed cross section is 7.46 pb.} +\caption{loose-tight data set composition for Type 3 $\tau$ when $\sigma_{t\bar{t}}$ = 7.46 pb is assumed.} \label{loosetight_3} \end{table}