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# V+jet/V 

Nov 15th 2012. V+jet/V . Found the histograms that I used to unfold the Wg Njet distributions, to cross check with Zhijun The signal and background histograms are provided by Camilla, Feng and Li Contains Njet distributions from the non-tight and non-isolated control regions

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## V+jet/V 

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1. Nov 15th 2012 V+jet/V • Found the histograms that I used to unfold the Wg Njet distributions, to cross check with Zhijun • The signal and background histograms are provided by Camilla, Feng and Li • Contains Njet distributions from the non-tight and non-isolated control regions • Subtract away EWK background, then normalized to the predicted W+jet background for Et(photon)>15 GeV • NOTE : the predicted # of W+jet background for each jet multiplicity bin taken from the Njet shape that we took from control region may not be exactly the same as the prediction that we made explicitly for each jet bin. • Use this W+jet Njet distribution to obtain # of W+jet for Njet>=1 • Get the statistical and systematic error • Apply the relative size of error onto the numbers that we predict using : • NWJet(Njet>=1) = NWJet(Njet>=0) - NWJet(Njet=0) • Unfortunately I do not have the histograms for Zgamma case.

2. Njet (W+jet, electron, Et(pho)>15 GeV) • NWJet(Njet>=1) = 410 +- 94(stat) +- 107(syst) • So will use 23% for stat and 26% for syst.

3. Njet (W+jet, muon, Et(pho)>15 GeV) • NWJet(Njet>=1) = 844 +- 162(stat) +- 192(syst) • So will use 19% for stat and 23% for syst.

4. W+jet/W (Et(pho)>15 GeV) • Use fractional errors from Njet distribution of W+jet for Njet>=1 (see page 2,3) • Do not consider error from Signal (rel. err is smaller, and do not want to double count error) • Difference in ratios (Sgn/Wj) between e and mu is about ~1.7  (stat), or ~1.1  (stat+syst) for Nj>=1 • Sgn/Wj ratios of e and mu channels are also compatible for Nj>=0 and Nj=0

5. W+jet/W (Et(pho)>15 GeV) • Compare ratios Nj>=0/Nj=0, and Nj=0/Nj>=1 for Wj and Signal, for e and mu • Difficult to compute error since the errors in are correlated in numerator and demominator • Ratios of signal are consistent between electron and muon channels

6. Njet distribution for Zgamma

7. Inclusive measurement : 2D sideband with Njet>=0 • Njet unfolding : extrapolation based on inclusive estimation Njet=1 Njet=0 Njet=2 Njet=3 Njet=0 Exclusive: 2D sideband with Njet=0

8. Z+jet/Z (Et(pho)>15 GeV) • Red number is taken from background estimation from Njet unfolding • Can not just subtract the background estimation for (Njet>=0) and Njet=0, it is wrong to do that. • S/B for electron channel is 2.1~4.3 (stat error , 1 sigma range ) • S/B for muon channel is 3.7~ 5.8 (stat error , 1 sigma range ) • Fully cover by 1 sigma

9. Backup

10. Z+jet/Z (Et(pho)>15 GeV) • Compare ratios Nj>=0/Nj=0, and Nj=0/Nj>=1 for Zj and Signal, for e and mu • Difficult to compute error since the errors are correlated in numerator and denominator • Ratios of signal are consistent between electron and muon channels

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