1. Top @ 10 TeV Updates on Efficiencies and Event Shapes Ken Johns, Venkat Kaushik, Xiaowen Lei (U. Arizona) Single lepton + jets channel

2. 2 Efficiencies  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 the following samples:  Ttbar: 105200 (mcatnlo), 105206 (acermc) in e/mu + jets chn  Wenu+Np: 108241, 108242, 108243; Wmunu+Np: 108244, 108245, 108246 Problems and to-dos:  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 bug-fixed samples are ready.  Will fill the table for KKgluon or Z’->ttbar samples once we can find rel14 samples on the grid. On the twiki page  https://twiki.cern.ch/twiki/bin/viewauth/AtlasProtected/TopCS BenchMark#Single_lepton_channel

3. 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. 4 e+jet Efficiencies  Efficiencies

5. 5 mu+jet Efficiency  Efficiencies

6. 6 10 TeV Top  We made preliminary comparison of 105200 samples and 105206 samples 5200: T1_McAtNlo_Jimmy; No Full Had; 202.86pb*1.07 5206: AcerMCttbarHerwig; No Full Had; 108.64pb*2.01  As a first step we looked at jet multiplicity, jet pt, and lepton pt spectrum Loose jet: et > 15GeV, abs(eta) < 2.5 Lepton: plots are without cuts  These plots show that the two samples are almost identical. No big difference are spotted  Further comparison will be made

7. 7 Comparison of 105200 and 105206 Jet pt:

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

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

10. 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 Cut 6 leaves too few events for the background  Added masschisq as one of the event shape variables masschisq = (hadTopMass – TopPDGmass)^2/Sigmajjb^2 + (lepTopMass – TopPDGmass)^2/Sigmalnb^2 + (hadWmass – WPDGmass)^2/Sigmajj^2  A total number of 12 transformed variables are currently used  See following slides for comparison plots  Improved fits to the template functions  See following slides for fittings

11. Topological Variables – e+jets log(ht): sum(et) for jets et>15GeV log(ht_2): log(et_j1+et_j2) log(ht_3): log(et_j3+et_j4) log(ht’_2): log(Sum(et)_j234/S um(pz)_j1234) log(he) is also used but not shown here 11

12. Topological Variables – e+jets log(centrality): log(ht/he) exp(-11apla): apla = 3/2Q_1 log(sphe): sphe = 3/2(Q_1+Q_2) 12

13. Topological Variables – e+jets Log(mjj_min): minimum dijet mass Use 4 leading jets dPhi: angle between leading lepton and missing et log(K’_Tmin): minimum dijet distance * et of the lower in the pair / hadronic W et masschisq 13

14. 14 Topological Variable Fits – e+jets

15. 15 Topological Variable Fits – e+jets

16. 16 Topological Variable Fits – e+jets

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

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

19. 19 Different Topo Variables from CDF

20. 20 Conclusions  Updated semi-leptonic efficiency tables and made preliminary comparison of 105200 and 105206 samples  Have improved fits and top likelihood Next will test the likelihood in ratio fitting and continue to optimize  We also would like to study lepton isolation for the trigger  Need additional background samples to increase the statistics Atlfast sample exist but no replicas on the grid? Maybe we should contact W+jets group.  mc08.10768*AlpgenJimmyWenuNp*_pt20.recon.AOD.e349_a68  mc08.10769*AlpgenJimmyWmunuNp*_pt20. recon.AOD.e349_a68  Will do the same for release 14 KKgluon or Z’->ttbar sample once we can find them on the grid KKgluon not ready yet? Z’->ttbar only privately generated?