Top @ 10 TeV Updates on Efficiencies and Event Shapes

1. Top @ 10 TeVUpdates on Efficiencies and Event Shapes Ken Johns, Venkat Kaushik, Xiaowen Lei (U. Arizona)

2. Introduction • We updated single lepton selection reference tables with event numbers after each cut • Mc event weight (either 1 or -1) are taken into account • Tables are filled for these samples: • Ttbar: 105200 (mcatnlo), 105206 (acermc) • Wenu+Np: 108241, 108242, 108243 • Wmunu+Np: 108244, 108245, 108246 • Problems: • For 105205 sample, we only see dilepton events. Is this a problem with the generation? • We will update the numbers for the background once the new good samples are ready. • On the twiki page • https://twiki.cern.ch/twiki/bin/viewauth/AtlasProtected/TopCSBenchMark#Single_lepton_channel

3. Cuts from the Spreadsheet • Cut 1 – lepton trigger • EF_e20i or EF_mu20 • Cut 2 – exactly 1 lepton with Pt>20GeV • Cut 3 – MET>20GeV • Cut 4 – 4 good jets with Pt>30GeV • Cut 5 – 3 good jets with Pt>40GeV • Cut 6 – 150<m_jj<190GeV

4. e+jet Efficiencies • Efficiencies

5. mu+jet Efficiency • Efficiencies

6. 10 TeV Top • We made preliminary comparison of 105200 samples and 105206 samples • To be added: detailed generation info • Looked at jet multiplicity, jet pt, and lepton pt spectrum • Results are compartible

7. Comparison of 105200 and 105206 Jet pt:

8. Comparison of 105200 and 105206 Jet mulplicity: Lepton pt spectrum:

9. Comparison of 105200 and 105206 • m(jjj) where jjj == highest vector Pt (e+jets):

10. Topological Variables • We use 108243/108247 samples for background, instead of using all 108241(2,3)/108245(6,7) samples. • Cuts have higher efficiency on 8243 and 8247, thus we get more statistics, and thus the influence of the “repeated events” is relatively small. • Use events which passed cuts 1-5. • Added masschisq as one of the event shape variables. A total number of 12 variables are currently used. • masschisq = (hadTopMass – TopPDGmass)^2/Sigmajjb^2 + (lepTopMass – TopPDGmass)^2/Sigmalnb^2 + (hadWmass – WPDGmass)^2/Sigmajj^2 • Improved the fits to the template functions.

11. Topological Variables – e+jets

12. Topological Variables – e+jets

13. Topological Variables – e+jets

14. Topological Variable Fits – e+jets

15. Topological Variable Fits – e+jets

16. Topological Variable Fits – e+jets

17. Topological Likelihood Lt e+jets: mu+jets:

18. Work in Progress to Optimize Topo Vars • We are comparing the jet pt distributions between sig and bkg, for 1st,2nd,3rd,4th leading jets, to find out what serves as the best combination. • We are also learning from CDF. • Some of the variables are similar (not exactly the same, for example, they use 3 leading jets for most variables instead of 4) • They also use some different variables • Also want to try TMVA package to find the best discrimator. • A simple macro for fitting the ratio is ready. • In the process of preparing simple mixed sample to test the likelihood

19. Different Topo Variables from CDF

20. Conclusions • Updated the single-lepton efficiency table • Numbers for the background will be updated as soon as we get bug-fixed samples • Made preliminary comparison between 105200 and 105206 samples • Improved fits and top likelihood • Next will test the likelihood in ratio fitting • Will continue to optimize likelihood • We also would like to study lepton isolation for the trigger • Need additional background samples to increase the statistics