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# Line 23 | Line 23 | detector.
23  
24   We find that in $t\bar{t}$ events SumJetPt and
25   \met$/\sqrt{\rm SumJetPt}$ are nearly uncorrelated,
26 < as demonstrated in Figure~\ref{fig:uncor}.
26 > as demonstrated in Fig.~\ref{fig:uncor}.
27   Thus, we can use an ABCD method in the \met$/\sqrt{\rm SumJetPt}$ vs
28   sumJetPt plane to estimate the background in a data driven way.
29  
# Line 42 | Line 42 | sumJetPt plane to estimate the backgroun
42   \caption{\label{fig:uncor}\protect Distributions of SumJetPt
43   in MC $t\bar{t}$ events for different intervals of
44   MET$/\sqrt{\rm SumJetPt}$. h1, h2, and h3 refer to the MET$/\sqrt{\rm SumJetPt}$
45 < intervals 4.5-6.5, 6.5-8.5 and $>$8.5, respectively.}
45 > intervals 4.5-6.5, 6.5-8.5 and $>$8.5, respectively. }
46   \end{center}
47   \end{figure}
48  
49   \begin{figure}[tb]
50   \begin{center}
51 < \includegraphics[width=0.5\linewidth, angle=90]{abcdMC.pdf}
51 > \includegraphics[width=0.75\linewidth]{ttdil_uncor_38X.png}
52   \caption{\label{fig:abcdMC}\protect Distributions of MET$/\sqrt{\rm SumJetPt}$ vs.
53 < SumJetPt for SM Monte Carlo.  Here we also show our choice of ABCD regions.}
53 > SumJetPt for SM Monte Carlo.  Here we also show our choice of ABCD regions. The correlation coefficient
54 > ${\rm corr_{XY}}$ is computed for events falling in the ABCD regions.}
55   \end{center}
56   \end{figure}
57  
58  
59   Our choice of ABCD regions is shown in Figure~\ref{fig:abcdMC}.
60   The signal region is region D.  The expected number of events
61 < in the four regions for the SM Monte Carlo, as well as the BG
62 < prediction AC/B are given in Table~\ref{tab:abcdMC} for an integrated
63 < luminosity of 35 pb$^{-1}$.  The ABCD method with chosen boundaries is accurate
64 < to about 20\%. As shown in Table~\ref{tab:abcdsyst}, we assess systematic uncertainties
65 < by varying the boundaries by an amount consistent with the hadronic energy scale uncertainty,
66 < which we take as $\pm$5\% for SumJetPt and $\pm$2.5\% for MET/$\sqrt{\rm SumJetPt}$, since the
67 < uncertainty on this quantity partially cancels due to the fact that it is a ratio of correlated
68 < quantities. Based on these studies we assess a correction factor $k_{ABCD} = 1.2 \pm 0.2$ to the
69 < predicted yield using the ABCD method.
61 > in the four regions for the SM Monte Carlo, as well as the background
62 > prediction A $\times$ C / B are given in Table~\ref{tab:abcdMC} for an integrated
63 > luminosity of 34.0 pb$^{-1}$. In Table~\ref{tab:abcdsyst}, we test the stability of
64 > observed/predicted with respect to variations in the ABCD boundaries.
65 > Based on the results in Tables~\ref{tab:abcdMC} and~\ref{tab:abcdsyst}, we assess
66 > a systematic uncertainty of 20\% on the prediction of the ABCD method.
67 >
68 > %As shown in Table~\ref{tab:abcdsyst}, we assess systematic uncertainties
69 > %by varying the boundaries by an amount consistent with the hadronic energy scale uncertainty,
70 > %which we take as $\pm$5\% for SumJetPt and $\pm$2.5\% for MET/$\sqrt{\rm SumJetPt}$, since the
71 > %uncertainty on this quantity partially cancels due to the fact that it is a ratio of correlated
72 > %quantities. Based on these studies we assess a correction factor $k_{ABCD} = 1.2 \pm 0.2$ to the
73 > %predicted yield using the ABCD method.
74  
75  
76   %{\color{red} Avi wants some statement about stability
# Line 75 | Line 80 | predicted yield using the ABCD method.
80   \begin{table}[ht]
81   \begin{center}
82   \caption{\label{tab:abcdMC} Expected SM Monte Carlo yields for
83 < 35 pb$^{-1}$ in the ABCD regions, as well as the predicted yield in
83 > 34.0~pb$^{-1}$ in the ABCD regions, as well as the predicted yield in
84   the signal region given by A $\times$ C / B. Here `SM other' is the sum
85   of non-dileptonic $t\bar{t}$ decays, $W^{\pm}$+jets, $W^+W^-$,
86   $W^{\pm}Z^0$, $Z^0Z^0$ and single top.}
87   \begin{tabular}{lccccc}
88 + %%%official json v3, 38X MC (D6T ttbar and DY)
89   \hline
90 <              sample   &                   A   &                   B   &                   C   &                   D   &                      A $\times$ C / B  \\
90 >              sample                     &                   A   &                   B   &                   C   &                   D   &                PRED  \\
91   \hline
92 < $t\bar{t}\rightarrow \ell^{+}\ell^{-}$   &   8.27  $\pm$  0.18   &  32.16  $\pm$  0.35   &   4.69  $\pm$  0.13   &   1.05  $\pm$  0.06   &   1.21  $\pm$  0.04  \\
93 < $Z^0 \rightarrow \ell^{+}\ell^{-}$       &   0.22  $\pm$  0.11   &   1.54  $\pm$  0.29   &   0.05  $\pm$  0.05   &   0.16  $\pm$  0.09   &   0.01  $\pm$  0.01  \\
94 <            SM other                     &   0.54  $\pm$  0.03   &   2.28  $\pm$  0.12   &   0.23  $\pm$  0.03   &   0.07  $\pm$  0.01   &   0.05  $\pm$  0.01  \\
92 > $t\bar{t}\rightarrow \ell^{+}\ell^{-}$   &   8.44  $\pm$  0.18   &  32.83  $\pm$  0.35   &   4.78  $\pm$  0.14   &   1.07  $\pm$  0.06   &   1.23  $\pm$  0.05  \\
93 > $Z^0 \rightarrow \ell^{+}\ell^{-}$       &   0.17  $\pm$  0.08   &   1.18  $\pm$  0.22   &   0.04  $\pm$  0.04   &   0.12  $\pm$  0.07   &   0.01  $\pm$  0.01  \\
94 >            SM other                     &   0.53  $\pm$  0.03   &   2.26  $\pm$  0.11   &   0.23  $\pm$  0.03   &   0.07  $\pm$  0.01   &   0.05  $\pm$  0.01  \\
95   \hline
96 <         total SM MC                     &   9.03  $\pm$  0.21   &  35.97  $\pm$  0.46   &   4.97  $\pm$  0.15   &   1.29  $\pm$  0.11   &   1.25  $\pm$  0.05  \\
96 >         total SM MC                     &   9.14  $\pm$  0.20   &  36.26  $\pm$  0.43   &   5.05  $\pm$  0.14   &   1.27  $\pm$  0.10   &   1.27  $\pm$  0.05  \\
97   \hline
98   \end{tabular}
99   \end{center}
# Line 98 | Line 104 | $Z^0 \rightarrow \ell^{+}\ell^{-}$
104   \begin{table}[ht]
105   \begin{center}
106   \caption{\label{tab:abcdsyst}
101 {\bf \color{red} Do we need this study at all? Observed/predicted is consistent within stat uncertainties as the boundaries are varied- is it enough to simply state this fact in the text??? }
107   Results of the systematic study of the ABCD method by varying the boundaries
108   between the ABCD regions shown in Fig.~\ref{fig:abcdMC}. Here $x_1$ is the lower SumJetPt boundary and
109   $x_2$ is the boundary separating regions A and B from C and D, their nominal values are 125 and 300~GeV,
# Line 109 | Line 114 | respectively.}
114   \hline
115   $x_1$   &   $x_2$ & $y_1$   &   $y_2$ & Observed/Predicted \\
116   \hline
117 < nominal & nominal & nominal & nominal & $1.20 \pm 0.12$    \\
118 < +5\%    & +5\%    & +2.5\%  & +2.5\%  & $1.38 \pm 0.15$    \\
119 < +5\%    & +5\%    & nominal & nominal & $1.31 \pm 0.14$    \\
120 < nominal & nominal & +2.5\%  & +2.5\%  & $1.25 \pm 0.13$    \\
121 < nominal & +5\%    & nominal & +2.5\%  & $1.32 \pm 0.14$    \\
122 < nominal & -5\%    & nominal & -2.5\%  & $1.16 \pm 0.09$    \\
123 < -5\%    & -5\%    & +2.5\%  & +2.5\%  & $1.21 \pm 0.11$    \\
124 < +5\%    & +5\%    & -2.5\%  & -2.5\%  & $1.26 \pm 0.12$    \\
117 >
118 > nominal & nominal & nominal & nominal & $1.00 \pm 0.08$    \\
119 >
120 > +5\%    & +5\%    & +2.5\%  & +2.5\%  & $1.08 \pm 0.11$    \\
121 >
122 > +5\%    & +5\%    & nominal & nominal & $1.04 \pm 0.10$    \\
123 >
124 > nominal & nominal & +2.5\%  & +2.5\%  & $1.03 \pm 0.09$    \\
125 >
126 > nominal & +5\%    & nominal & +2.5\%  & $1.05 \pm 0.10$    \\
127 >
128 > nominal & -5\%    & nominal & -2.5\%  & $0.95 \pm 0.07$    \\
129 >
130 > -5\%    & -5\%    & +2.5\%  & +2.5\%  & $1.00 \pm 0.08$    \\
131 >
132 > +5\%    & +5\%    & -2.5\%  & -2.5\%  & $0.98 \pm 0.09$    \\
133   \hline
134   \end{tabular}
135   \end{center}
# Line 142 | Line 155 | cut of 50 GeV, the rescaling factor is o
155  
156   \newcommand{\ptll} {\ensuremath{P_T(\ell\ell)}}
157   \begin{center}
158 < $ K = \frac{\int_0^{\infty} {\cal N}(\ptll)~~d\ptll~}{\int_{50}^{\infty} {\cal N}(\ptll)~~d\ptll~}$
158 > $ K = \frac{\int_0^{\infty} {\cal N}(\ptll)~~d\ptll~}{\int_{50}^{\infty} {\cal N}(\ptll)~~d\ptll~} = 1.5$
159   \end{center}
160  
161  
149 Monte Carlo studies give values of $K$ that are typically between 1.5 and 1.6,
150 depending on selection details.  
162   %%%TO BE REPLACED
163   %Given the integrated luminosity of the
164   %present dataset, the determination of $K$ in data is severely statistics
# Line 195 | Line 206 | The results are summarized in Table~\ref
206   \begin{table}[htb]
207   \begin{center}
208   \caption{\label{tab:victorybad}
198 {\bf \color{red} Need to either update this with 38X MC  or remove it }
209   Test of the data driven method in Monte Carlo
210 < under different assumptions.  See text for details.}
210 > under different assumptions, evaluated using Spring10 MC.  See text for details.}
211   \begin{tabular}{|l|c|c|c|c|c|c|c|c|}
212   \hline
213   & True $t\bar{t}$ dilepton & $t\to W\to\tau$& other SM & GEN or  & Lepton $P_T$    & Z veto & \met $>$ 50& obs/pred \\
# Line 218 | Line 228 | under different assumptions.  See text f
228   \begin{table}[htb]
229   \begin{center}
230   \caption{\label{tab:victorysyst}
231 < {Summary of uncertainties in $K_C$ due to the MET scale and resolution uncertainty, and to backgrounds other than $t\bar{t} \to$~dilepton.
231 > Summary of variations in $K_C$ due to the MET scale and resolution uncertainty, and to backgrounds other than $t\bar{t} \to$~dilepton.
232   In the first table, `up' and `down' refer to shifting the hadronic energy scale up and down by 5\%. In the second table, the quoted value
233   refers to the amount of additional smearing of the MET, as discussed in the text. In the third table, the normalization of all backgrounds
234 < other than $t\bar{t} \to$~dilepton is varied.
225 < {\bf \color{ref} Should I remove `observed' and `predicted' and show only the ratio? }}
226 <
234 > other than $t\bar{t} \to$~dilepton is varied. }
235   \begin{tabular}{ lcccc }
236   \hline
237         MET scale  &      Predicted       &       Observed       &       Obs/pred       \\
238   \hline
239 <        nominal   &  0.92 $ \pm $ 0.11   &  1.29 $ \pm $ 0.11   &  1.40 $ \pm $ 0.20   \\
240 <            up    &  0.92 $ \pm $ 0.11   &  1.53 $ \pm $ 0.12   &  1.66 $ \pm $ 0.23   \\
241 <          down    &  0.81 $ \pm $ 0.07   &  1.08 $ \pm $ 0.11   &  1.32 $ \pm $ 0.17   \\
242 < \hline
243 <
244 < \hline
245 <   MET smearing   &      Predicted       &       Observed        &       Obs/pred      \\
246 < \hline
247 <        nominal   &  0.92 $ \pm $ 0.11   &  1.29 $ \pm $ 0.11   &  1.40 $ \pm $ 0.20   \\
248 <           10\%   &  0.90 $ \pm $ 0.11   &  1.30 $ \pm $ 0.11   &  1.44 $ \pm $ 0.21   \\
249 <           20\%   &  0.84 $ \pm $ 0.07   &  1.36 $ \pm $ 0.11   &  1.61 $ \pm $ 0.19   \\
250 <           30\%   &  1.05 $ \pm $ 0.18   &  1.32 $ \pm $ 0.11   &  1.27 $ \pm $ 0.24   \\
251 <           40\%   &  0.85 $ \pm $ 0.07   &  1.37 $ \pm $ 0.11   &  1.61 $ \pm $ 0.19   \\
252 <           50\%   &  1.08 $ \pm $ 0.18   &  1.36 $ \pm $ 0.11   &  1.26 $ \pm $ 0.24   \\
253 < \hline
254 <
255 < \hline
256 <  non-$t\bar{t} \to$~dilepton scale factor   &          Predicted   &           Observed   &           Obs/pred   \\
249 < \hline
250 <   ttdil only                                &  0.77 $ \pm $ 0.07   &  1.05 $ \pm $ 0.06   &  1.36 $ \pm $ 0.14   \\
251 <   nominal                                   &  0.92 $ \pm $ 0.11   &  1.29 $ \pm $ 0.11   &  1.40 $ \pm $ 0.20   \\
252 <   double non-ttdil yield                    &  1.06 $ \pm $ 0.18   &  1.52 $ \pm $ 0.20   &  1.43 $ \pm $ 0.30   \\
239 >        nominal   &  0.92 $ \pm $ 0.09   &  1.27 $ \pm $ 0.10   &   1.39 $ \pm $ 0.18  \\
240 >            up    &  0.90 $ \pm $ 0.09   &  1.58 $ \pm $ 0.10   &   1.75 $ \pm $ 0.21  \\
241 >          down    &  0.70 $ \pm $ 0.06   &  0.96 $ \pm $ 0.09   &   1.37 $ \pm $ 0.18  \\
242 > \hline
243 >   MET smearing   &      Predicted       &       Observed       &       Obs/pred       \\
244 > \hline
245 >        nominal   &  0.92 $ \pm $ 0.09   &  1.27 $ \pm $ 0.10   &   1.39 $ \pm $ 0.18  \\
246 >           10\%   &  0.88 $ \pm $ 0.09   &  1.28 $ \pm $ 0.10   &   1.47 $ \pm $ 0.19  \\
247 >           20\%   &  0.87 $ \pm $ 0.09   &  1.26 $ \pm $ 0.10   &   1.44 $ \pm $ 0.19  \\
248 >           30\%   &  1.03 $ \pm $ 0.17   &  1.33 $ \pm $ 0.10   &   1.29 $ \pm $ 0.23  \\
249 >           40\%   &  0.88 $ \pm $ 0.09   &  1.36 $ \pm $ 0.10   &   1.55 $ \pm $ 0.20  \\
250 >           50\%   &  0.80 $ \pm $ 0.07   &  1.39 $ \pm $ 0.10   &   1.73 $ \pm $ 0.19  \\
251 > \hline
252 >  non-$t\bar{t} \to$~dilepton bkg   &       Predicted   &           Observed   &           Obs/pred   \\
253 > \hline
254 >   ttdil only                       &   0.79 $ \pm $ 0.07   &   1.07 $ \pm $ 0.06   &   1.36 $ \pm $ 0.14   \\
255 >   nominal                          &   0.92 $ \pm $ 0.09   &   1.27 $ \pm $ 0.10   &   1.39 $ \pm $ 0.18   \\
256 >   double non-ttdil yield           &   1.04 $ \pm $ 0.15   &   1.47 $ \pm $ 0.16   &   1.40 $ \pm $ 0.25   \\
257   \hline
258   \end{tabular}
259   \end{center}
260   \end{table}
261  
258
259
262   The largest discrepancy between prediction and observation occurs on the first
263   line of Table~\ref{tab:victorybad}, {\em i.e.}, at the generator level with no
264   cuts.  We have verified that this effect is due to the polarization of
# Line 279 | Line 281 | not include effects of spin correlations
281   We have studied this effect at the generator level using Alpgen.  We find
282   that the bias is at the few percent level.
283  
284 < Based on the results of Table~\ref{tab:victorybad}, we conclude that the
284 > Based on the results of Table~\ref{tab:victorysyst}, we conclude that the
285   naive data-driven background estimate based on $P_T{(\ell\ell)}$ needs to
286 < be corrected by a factor of $ K_C = 1.4 \pm 0.2(stat)$.
286 > be corrected by a factor of $ K_C = 1.4 \pm 0.2({\rm stat})$.
287  
288 < The 2 dominant sources of systematic uncertainty in $K_C$ are due to non-$t\bar{t} \to$~dilepton backgrounds,
289 < and the MET scale and resolution uncertainties. The impact of non-$t\bar{t}$-dilepton background is assessed
290 < by varying the yield of all backgrounds except for $t\bar{t} \to$~dilepton, as shown in Table~\ref{table_kc}.
291 < The systematic is assessed as the larger of the differences between the nominal $K_C$ value and the values
288 > The dominant sources of systematic uncertainty in $K_C$ are due to non-$t\bar{t} \to$~dilepton backgrounds,
289 > and the MET scale and resolution uncertainties, as summarized in Table~\ref{tab:victorysyst}.
290 > The impact of non-$t\bar{t}$-dilepton background is assessed
291 > by varying the yield of all backgrounds except for $t\bar{t} \to$~dilepton.
292 > The uncertainty is assessed as the larger of the differences between the nominal $K_C$ value and the values
293   obtained using only $t\bar{t} \to$~dilepton MC and obtained by doubling the non $t\bar{t} \to$~dilepton component,
294 < giving an uncertainty of $0.04$.
294 > giving an uncertainty of $0.03$.
295  
296   The uncertainty in $K_C$ due to the MET scale uncertainty is assessed by varying the hadronic energy scale using
297 < the same method as in~\ref{} and checking how much $K_C$ changes, as summarized in Table~\ref{tab:victorysyst}.
298 < This gives an uncertainty of 0.3. We also assess the impact of the MET resolution uncertainty on $K_C$ by applying
299 < a random smearing to the MET. For each event, we determine the expected MET resolution based on the sumJetPt, and
300 < smear the MET to simulate an increase in the resolution of 10\%, 20\%, 30\%, 40\% and 50\%. The results show that
301 < $K_C$ does not depend strongly on the MET resolution and we therefore do not assess any uncertainty.
297 > the same method as in~\cite{ref:top}, giving an uncertainty of 0.36.
298 > We also assess the impact of the MET resolution
299 > uncertainty on $K_C$ by applying a random smearing to the MET. For each event, we determine the expected MET resolution
300 > based on the sumJetPt, and smear the MET to simulate an increase in the resolution of 10\%, 20\%, 30\%, 40\% and 50\%.
301 > The results show that $K_C$ does not depend strongly on the MET resolution and we therefore do not assess any uncertainty.
302  
303   Incorporating all the statistical and systematic uncertainties we find $K_C = 1.4 \pm 0.4$.
304  
# Line 331 | Line 334 | presence of the signal.
334   \caption{\label{tab:sigcont} Effects of signal contamination
335   for the two data-driven background estimates. The three columns give
336   the expected yield in the signal region and the background estimates
337 < using the ABCD and $P_T(\ell \ell)$ methods. Results are normalized to 35~pb$^{-1}$.}
337 > using the ABCD and $P_T(\ell \ell)$ methods. Results are normalized to 34.0~pb$^{-1}$.}
338   \begin{tabular}{lccc}
339   \hline
340              &      Yield      &      ABCD    & $P_T(\ell \ell)$  \\
341   \hline
342 < SM only     &       1.29      &      1.25    &           0.92    \\
343 < SM + LM0    &       7.57      &      4.44    &           1.96    \\
344 < SM + LM1    &       3.85      &      1.60    &           1.43    \\
342 > SM only     &       1.3      &      1.3    &       0.9        \\
343 > SM + LM0    &       7.4      &      4.4    &       1.9        \\
344 > SM + LM1    &       3.8      &      1.6    &       1.4        \\
345 > %SM only     &       1.27      &      1.27    &       0.92        \\
346 > %SM + LM0    &       7.39      &      4.38    &       1.93        \\
347 > %SM + LM1    &       3.77      &      1.62    &       1.41        \\
348   \hline
349   \end{tabular}
350   \end{center}

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