Etmiss reconstruction and calibration session

1. Etmiss reconstructionand calibration session Contributions by: Donatella Cavalli, Rosa Simoniello, Silvia Resconi Irene Vichou James Dagenhardt Joao Gentil Saraiva Peter Loch David Lopez Mateos RachidMazini Hugh Skottowe ChenguangZhu Teresa Barillari

2. Outline of the session • MET performance in 2011 data in Z, W and dijet samples: • Comparisons of different MET_RefFinal configurations to provide the best configuration for physics analysis. (in resolution, tails, linearity) • Data vs MC comparison for the “best” configuration in different physics channels: • Validation of the MET_Ref terms • SumET distributions • Comparison of MET_RefFinal calculated in |h|< 4.5 and |h|< 5 • MET Resolution vsSumET: • First attempts and ideas to suppress pile-up in MET_RefFinal • Dependence of MET on beam conditions: number of primary vertices, mu, position in bunch train • Update of MET calculated from tracks: an example about how it can be used in analyses.

3. MET changes in rel 17 All results presented in this session are based on rel 16, unfortunately rel 17 D3PD production is not yet ready and few basic changes have been implemented in MET reconstruction:  change of input jet collection in default MET_RefFinal from Antikt6LCTopo to Antikt4LCTopo due to known problems with JES in rel17 for Antikt6 collection. • Improvements in MET_MuonBoy term proposed by muon experts (some details in Adam’s talk) Luckily in out set of configurations for MET_RefFinal we had foreseen a configuration with Antikt4LCTopo for MET_RefFinal calculation, so that you will see some results already with this configuration that is the new default in rel17.

4. COMPARISON OF DIFFERENT Met_RefFinal CONFIGURATIONS

5. Datasets and Selections • Official Jet/Etmiss D3PDs produced by Toshitag p621/p623 • Data from different periods: • G-J: L_int about 1.2 fb-1 • Skimmed/selected data for different physics channel: Zee, Zmumu, Wenu, Wmunu, di-jets • Apply same selections on data and on MC ( same selection applied as in MET paper, a part from larError cut) • MC reweighted using official PAT tool (use both available methods  small difference)

6. Comparison of different MET_RefFinal configurations • The “preferred” RefFinal for 2010 data is based on AntiKt6 jets(shown in MET paper) • In rel17 decided to move to AntiKt4LCTopo due to problems with RefFinal Antikt6 • Comparison of MET and SET for different MET_RefFinal in Zee events: RF Antikt4 = RefJet and SoftJet with Antikt4LCTopo, CellOut_Eflow RF Antikt6 = RefJet and SoftJet with Antikt6LCTopo, CellOut_Eflow RF LCW = RefJet and SoftJet with Antikt6LCTopo, NO JES in RefJet and NO eflow in CellOut. (similar to LocHadTopo) RF em= RefJet and SoftJet with Antikt4TopoEM, CellOut at EM scale RF AntiKt6 has larger mean and width value in MET and SET

7. Comparison of MET_RefFinal terms in Zee events CellOutEflow RefJet SoftJets MET MET MET SET SET SET MET CellOut without eflow (RF LCW) presents more tailswith respect to RF Antikt4/6 In RF Antikt4 ,SET CellOut is increased , while SET RefJetdecreases with respect to RF Antikt6

8. Comparison of METx,y resolution vs SET for different MET_RefFinal configurations in Zee events Events with no jets pT>20GeV All events MET_RefFinalAntiKt6 shows a deviation form the expected behaviour in events with jets: is this due to pile-up ? Is this dueto jet resolution or non- closure problemof JES in Antikt6LCTopo ? In any case choosing a smaller cone for the input jet collections to RefJet helps against pile-up ,less risk that JES is applied energy from pile-up. One possibility could be to apply the JES in RefJet term only for jets with high JVF .

9. Comparison of the scaled METx,y resolution for different MET_RefFinal Zee • MET resolutions scaledby the ratioofSET (EM)/SET (CALIB)vsSET (EM) • MET_RefFinalAntiKt4 shows aslightly better resolution in Z events

10. I think that in this spot we can move the slide of David Lopes (slide 30) about the CellOut calibration. This is the last occasion where “calibration” can be mentioned I think. Maybe you can say that the baseline MET is the akt4 etc etc, but David has started to think if one can calibrated the CellOut term with NI based on MC and he has done some investigation in dijet event. (and you let him talk on one slide)

11. Data-mc comparison for RF Antikt4

12. RefFinal AntiKt4 distributions for Zee METx METy • METx, METy, MET, Sumet and Met_phi distributions for RefFinal Antikt4 MC events are weighted on their cross-section and then renormalized to the number of event in data (shape comparison) MET METphi • Good data-MC agreement

13. RefFinal AntiKt4 terms for Zee RefEle RefJet • MET distributions for RefEle, RefJet (pT>20GeV), SoftJets (10GeV<pT<20GeV) and CellOutEflow SoftJets CellOutElfow • Good data-MC agreement in all terms

14. RefFinal AntiKt4 distributions for Zµµ • METx, METy, MET, SumET and Met_phi distributions for RefFinal Antikt4 METy METx • Good data-MC agreement MET METphi

15. RefFinal AntiKt4 terms for Z µµ MET_MuonBoy MET_RefMuon • MET_MuonBoy distribution: good data-mc agreement • MET_RefMuondistribution (muonenergydeposited in calorimeters) : good data-mc agreement

16. SUMET distributions

17. SumET distributions for RefFinal Antikt4 Zmumu Zee Wenu Wmunu • Disagreement between data and MC except for Wenu(above ~100 GeV)

18. SumETterms for RefFinal AntiKt4 Zee • Sumet distributions for RefEle, RefJet (pT>20GeV), SoftJets (10GeV<pT<20GeV) and CellOut RefEle RefJet SoftJets CellOutElfow • Disagreement in RefJet, SoftJets and CellOutEflow distributions

19. SumETRefFinal Antikt4 distributions in h regions Zee 1.5 < |h| < 3.2 3.2 < |h| < 4.5 |h| < 1.5 SumET disagreement between data and MC increases with increasing h

20. COMPARISON OF REFFINAL CALCULATED IN|h|<4.5 AND |h|< 5

21. RefFinal AntiKt4 in|h|<4.5 vs |h|< 5 Zee |h| < 5 |h| < 4.5 MET • MET and METphi distributions for Zee events: METphi |h| < 4.5 |h| < 5 • Very similar data-mc agreement of distributions in |h|<4.5 and |h|< 5

22. RefFinal AntiKt4 resolution in |h|< 4.5 vs |h|<5 |h|<4.5 |h|<5 Zee Zee Going from|h|<4.5 to|h|< 5 MET Resolution shows the same behaviour both In Zee and di-jets events Di-jets Shall we move to MET in |h|< 5 ?

23. MET Resolution VS sumet

24. MET resolution vsSumET for Z, W Data MC MET resolutions in 2011 data are worse by ≈ 50 % for Zand W both for data and MCwith respect to results in 2010 data

25. Zee Trying to understand worsening of MET resolution due to pile-up <nvert> • Relation between nvert and mu • Resolutions for different <µ> values (bottom left) and for different number of vertices (bottom right) <µ> METx,y resolution gets worse with increasing <mu>, while no dependence is shown respect to number of vertices

26. This statement is not worth a separate slide but I believe it has to be mentioned. I have followed this work, this is Ok to say. (without any plots). You may want to think where is best to put. One more note to be mentioned from Ch.Zhu’s contribution: In studies in MC events (ttbar, W->enu, W->munu, Z->ee and Z->mumu) of the dependence of the stochastic term “a” of the MET resolution vs NPV. - This term “a” increases with NPV for all flavors of MET_RefFinal tested. - This increase of the MET resolution using 0.6 jets is steeper than the increase of the one made from 0.4 jets.

27. FIRST AttEMPTS AND IDEAS TO SUPPRESS PILE-UP IN MET REfFinal

28. Zee HT RefFinal resolution vsSumET HT x,y = MET_RefFinalx,y - MET_CellOutEflowx,yfor RefFinal Antikt4 HT_RefFinal: fit 0.73 √Σ ET CellOutEflow SoftJet RefJet MET_CellOutEflow is the term which gives the major contributions to SumET, in particular in the cases in which the input jet collection has a small cone like in case of RefFinal Antikt4. RemovingCellOutEflow the resolutionisspoiled.

29. Attempt to use JVF to suppress pile-up in MET_RefJet and SoftJet Method: Using the composition map available in D3PD, possibility to recalculate MET_RefJet and MET_SoftJetremoving jets with |JVF| < XX Zee JVF distribution: Jets from primary vertex Jets from pile-up Jets without matched tracks Jets with some contribution from pile-up

30. 3 attempt shown (many more tested !) Recalculate RefJet and SoftJet keeping only jets with |JVF| >= 0.75 Recalculate RefJet and SoftJet removing only jets with |JVF| =0 Select only evens with ALL jets with JVF=1 1 2 In cases 1 and 2 MET resolution is spoiled due to the fact that entire jets are removed from RefFinal calculation. In case 3 selected events without jets from pile-up, the resolution improves but the statistics is much reduced, as expected. 3

31. Proposal to calibrated the CellOut term

37. Idea by Peter to suppress pile-up fluctuations in MET_RefFinal the idea consists in applying also to MET_RefFinal the “jet area” method : - studies require access to TopoClusters in event (non-standard D3PD) and use of FastJet (all code needed for studies below is available in FastJet) - recluster full event (all TopoClusters, also the ones that are used by physics objects) with Kt, R = 0.4 and _no_ pT cut on the found jets and determine the median Et density per jet in bins of eta, rho(eta) - calculate for each TopoCluster in CellOut the ratio Et(cluster)/rho(eta) - recalculate CellOut for various cuts on this ratio (standard CellOut no cut, then Et(cluster)/rho(eta) > 0.5, 1.0, 1.5, 2.0, … - study MET resolution as function of these cuts to optimize it, also in the above mentioned <mu>, Npv bins (to verify that rho automatically corrects for residual effects from these two event characteristics)

38. Here the discussion needs to be opened, ask the audience for opinions.

39. Dependence of MET and SumETON BEAMparameters

40. MET, SET and METx,y for RefFinal Antikt4distributions as a function of nvert/<µ> Zee MET vsnvert SET vsnvert METx,yvsnvert SET vs <µ> MET vs <µ> METx,yvs<µ>

41. Zee MET vs distance from train front MET vsnvert • Z->ee events • rel16, comparison of: • LocHadTopo • MET_RefFinal with akT 0.6 jets • MET_RefFinal with akT 0.4 jets • (last is the default for rel17) • on: Nr of vertices, mu, distance from train front • The 0.4 case shows weaker dependence on above variables. MET vs <µ>

42. MET_RefFinal with akT 0.4 and 0.6 jets (Z->ee events) • dependence on Nr of primary vertices in bins of mu • dependence on the distance from the front of train in bins of mu • the weaker dependence on the NPV and distance from front for akT 0.4 is more evident in high mu values MET vsnvert in bins of mu MET vs distance from train front MET vs distance from train front

43. CellOut_eflow dependence on NPV in mu slices and on mu in NPV slices In this and next page notice scale difference in y axis between akT6 and aKT4!

44. CellOut_eflow dependence on dist. from front in mu and NPV slices The plots of the last two pages when compared to the MC will be used for extracting differences related to the in-time and out-of-time pileup.

45. Update of MET calculated from tracks

46. Conclusion • Use RF AntiKt4  best resolution in 2011 data • Good data-MC agreement in Z and W events • Met_RefFinalresolution much worse than in 2010. • Need a strategy for pile-up treatment in MET. • Dependence of MET and its resolution has been shown as a function of nr of vertices, mu, BCID and agrees reasonably with MC10b reweighted. • SumETis in disagreement

47. BACK-UP

48. RFs configurations • RF eflow4  new “preferred” RF • RF AntiKt6  JES bug • RF LCW  corresponding to LocHadTopo+MuonBoy-RefMuon_Track

49. Zµµ Terms RF AntiKt4 distributions • MuonBoy distribution: good data-mc agreement for both MET and SET SET MET • RefMuon distribution (calomuons): good data-mc agreement for both MET and SET SET MET

50. ZeeRF AntiKt4 distributions |h|<5 • METx, METy, MET, Sumet and Metphi distributions for RefFinal_LCW_NI_eflow4 METx METy MET METphi • Same data-mc agreement of distributions in |eta|<4.5 => can now move to |h|<5?