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ZZ ll nn analysis: WW/Top/Z tt Differential Background Estimation. Lailin Xu 1,2 , Bing Zhou 1 Univ. of Michigan Univ. of Sci. and Tech. of China. WW/Top/Z tt differential background estimation. Differential background spectrum
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ZZllnn analysis:WW/Top/Ztt Differential Background Estimation Lailin Xu1,2, Bing Zhou1 Univ. of Michigan Univ. of Sci. and Tech. of China
WW/Top/Ztt differential background estimation Differential background spectrum 1) Estimate the total background first, then scale the MC prediction to the DD estimation, but keep the MC shape 2) Estimate the background in each bin separately Binning: Zpt binning test – last bin will be the overflow bin 5 bins: 4 bins in 50-130 GeV, with bin width 20 GeV; and > 130 GeV 3 bins: 2 bins in 50-130 GeV, with bin width 40 GeV; and > 130GeV dPhi(ll): 6 bins: 5 bins in 0-2.5, with bin width 0.5; and > 2.5 3 bins: 2 bins in 0-2, with bin width 1; and > 2
ZpT distribution The last bin will give the most sensitivity for aTGC limit Combined: for ZpT > 130 GeV: data: 16 evemts, Prediction: 18.7 events
ZpT distribution: 3 bins Overflow has been added to the last bin. combined ee mm All backgrounds are from MC, but WW/Top/Ztt, W+jets, Z+jets have beem scaled to match the DD estimation respectively.
Differential WW/Top/Ztt background estimation in 3 bins mm ee Using DD method in each bin. DD and MC are consistent.
ZpT disctribution: 5 bins combined ee mm All backgrounds are from MC, but WW/Top/Ztt, W+jets, Z+jets have beem scaled to match the DD estimation respectively.
Differential WW/Top/Ztt background estimation in 5 bins mm ee Using DD method in each bin. DD and MC are consistent.
dPhi(ll) distribution: 6 bins combined ee mm All backgrounds are from MC, but WW/Top/Ztt, W+jets, Z+jets have beem scaled to match the DD estimation respectively.
dPhi(ll) distribution: 3 bins ee combined mm All backgrounds are from MC, but WW/Top/Ztt, W+jets, Z+jets have beem scaled to match the DD estimation respectively.
Summary WW/Top/Ztt background estimated in different ZpT bins and in different delta-Phi bins Data and MC corss-check are done for differential spectra. Good agreement observed. Suggest to use 3 ZpT bins for aTGC fitting: 50-90, 90-130, > 130 GeV