1. Yu Bai (IHEP, Beijing) On behalf of the SUSY Weak Production team ACCM 23, Mar 3, 2013 Search of SUSY Weak Production with hadronic taus Search of SUSY Weak Production with hadronic taus

2. SUSY Approval Meeting2 Support note: https://cds.cern.ch/record/1500884 Editors: Anyes Taffard Christophe Clement Federica Legger Xuai Zhuang Editorial Board: Dan Tovey (chair) Shirkma Bressler Masahiro Kuze Sadrine Laplace Present study on 20.69 fb -1, √s=8 TeV Data Conference note: https://cds.cern.ch/record/1519195

3. Outline Introduction Signal grids Object and event selection Signal region definition Background estimation Results Interpretation Summary SUSY Approval Meeting3

4. Introduction  Either for natural SUSY, or heavy scalars, it is fairly generic for the gauginos to be light.  Higgs into di-photon rate can be enhanced via staus without changing the Higgs to WW/ZZ rates, so light stau with large mixing may help  First study of direct gaugino through the final states with at least two taus, which is complementary of emu final states. SUSY Approval Meeting4

5. Signal Grids Direct Gaugino Decay pMSSM Signal Grid: Heavy Squarks and Gluinos tan β = 50 M 1 = 50 GeV M 2 and μ ranging from 100 to 500 GeV Mass of stau fixed at 95 GeV, other sleptons are heavy Mode A (chargino-neutralino decay): Mode C (chargino-chargino decay): SUSY Approval Meeting5

6. Objects Pre-Selection Electrons and muons Base line Selection Overlap removal Taus Baseline Overlap removal Loose tauid Tight tauid(at least 1 in each event) MET : Egamma10NoTau Trigger : Di-tau trigger || soft-met trigger Di-tau Trigger: EF_tau29Ti_medium1_tau20Ti_Medium_1 Soft-met Trigger: EF_xe80_tclcw Jet : Baseline Overlap removal L25: light jet B20: bjet F30: forward jet SUSY Approval Meeting6

7. SR definition SR definition Two SRs have been defined require at least 1 OS tau pair one SR is after jet veto another SR is only applying bjet veto Suppress Z+jets BG through Z-veto MET>40 GeV to suppress fake tau background Apply large m T2 cut to enhance SUSY sensitivity m T2 cut has been optimized SUSY Approval Meeting7

8. SR Optimization - mode A m T2 > 80 GeV m T2 > 90 GeVm T2 > 100 GeV m T2 jet veto m T2 b-veto m T2 jet-veto: pick m T2 >90 GeV (similar performance) m T2 b-veto: m T2 >100 GeV (best performance) Other models are checked, consistent with mode A 8 5fb-1 data used mT2 jet veto Mt2>80GeV: 3 Mt2>90GeV: 2 Mt2>100GeV: 1 mT2 b-veto Mt2>80GeV: 20 Mt2>90GeV: 4 Mt2>100GeV: 2 SUSY Approval Meeting

9. Background components in SRs Two classes of backgrounds: fake tau (qcd+W, ~75-80%) and real tau background (top, Z+jets, diboson) Fake tau background: estimated with data-driven approach (ABCD method ） Real tau background: use MC simulation SUSY Approval Meeting9

10. Background Estimation : fake tau background SUSY Approval Meeting10 Fake Background QCD di-jet (2 fake tau) W+jets (1 fake tau) Can be estimated together due to same fake tau character Not modeled well in MC due to fake rate Huge cross section, limited MC statistics

11. The ABCD method Use transfer factor (TF) from QCD events (low m T2 region from data) and take the TF difference between QCD and W+jets as systematics SUSY Approval Meeting11 Variables: m T2, tauid Base line control region A high m T2, loose tauid B low m T2,, loose tauid C low m T2, tight+medium tauid extrapolation from A to D through a TF (C/B) Alternative ABCD method checked (W CR-AB)

12. Correlation between tauid and m T2 m T2 jet vetom T2 b-veto No strong correlation between tau id and mT2 The correlation has been taken into account to syst. SUSY Approval Meeting12

13. Fake tau background purity m T2 jet vetom T2 b-veto 2 loose tauid tight tau veto 1 tight tau +1medium tau In QCD+W CR-C,B (low m T2 region), QCD + W purity is high (>96%) In QCD+W CR-A (high m T2 region), QCD+W purity is ~90% non fake tau bkg in CR-A has been subtracted from MC and taken into account to syst. SUSY Approval Meeting13

14. Signal contamination in region A m T2 jet-veto m T2 b-veto Mode A Mode C The SUSY contamination in the QCD+W control region A is around 10% for SR OS-mT2 and OS-mT2-nobjet SUSY Approval Meeting14

15. Fake tau background estimation: Result m T2 jet veto m T2 b-veto  Good Data/MC Agreement in non-signal region (mT2 < 90 GeV) QCD+W Results: In m T2 - jet veto region : 8.38+/-2.98 In m T2 b-veto region : 12.23+/-4.48 SUSY Approval Meeting15

16. Kinematic distributions  Good data/MC agreement for leading and next leading tau pt and eta distributions  The ABCD method works well SUSY Approval Meeting16

17. Validation of QCD+W estimation I  We validated QCD+W estimation in different SM bkg enriched region.  The QCD+W control region definition is close to SM BG validation regions but use loose tau id SUSY Approval Meeting17

18. Validation of QCD+W estimation I  Good data/MC agreement in all BG enriched VRs SUSY Approval Meeting18

19. Validation of QCD+W estimation II: Alternative ABCD Method  We also checked the QCD+W estimation using CRs with different bkg components (1L+1M w/o tight).  Good data/MC agreement in alternative ABCD method  The ABCD method proves to be reliable even change the components in the control regions SUSY Approval Meeting19

20. Real Tau Background Estimation and Validation  top and Z+jets:  No event left at one of the SRs due to low statistics  use “ABCD”-like MC driven estimation as default  CR definition is similar as QCD+W CR definition but from MC events (loose tau id, remove MET cut)  Diboson has reasonable statistics, use the MC simulation directly and validated with above “ABCD”-like method  we use two different sets of SFs for real and fake taus. This is why we don't check that all taus are real when we use MC SUSY Approval Meeting20

21. Real Tau Background  The numbers in SRs are consistent between MC prediction and MC- driven estimation within statistical uncertainty SUSY Approval Meeting21

22. Results  Results from SM Bkg estimation are compared with the total number of data events in table 19  mT2 distribution for data and SM bkg in eash SR is at fig 20.  The observed and expected number of events in the table (together with uncertainty) are used to calculate the exclusion limit SUSY Approval Meeting 22

23. Model independent upper limits on the visible cross-section  Table 22 shows the model-independent upper limits based on the observed and expected number of events in each SR SUSY Approval Meeting23

24. Best Exclusion Limits – simplified model SUSY Approval Meeting24  Masses of degenerate and are excluded up to 300-330 GeV in the chargino-neutralino simplified model for light (below 50-100 GeV); In the chargino-chargino simplified model, we exclude masses of 200< <330GeV for very light ( below 30- 50GeV)

25. Best Exclusion Limits - pMSSM Holes formed due to relatively lower signal yield with higher statistical err. SUSY Approval Meeting25

26. Summary  Two signal regions with high mT2 cut have been defined and optimized  No significant excess observed in the signal regions.  Given exclusion limits with pMSSM and simplified model (mode A,C)  Masses of degenerate and are excluded up to 300-330 GeV in the chargino-neutralino simplified model for light (below 50-100 GeV)  In the chargino-chargino simplified model, we exclude masses of 200< <330GeV for very light (below 30- 50GeV)  Aiming at Moriond CONF note SUSY Approval Meeting26

27. Backup SUSY Approval Meeting27

28. Acceptance*Efficiency of at least two taus for signal grid SUSY Approval Meeting28

29. Triggers Using following Oring trigger: EF tau29Ti medium1 tau20Ti medium1 => 2taus, p T leading > 40, p T next-leading > 25 GeV EF xe80 tclcw, =>MET> 150 GeV Good Turn-on Curve Efficiency of EF_xe80_tclcw Trigger Matching Leading tau matches to EF tau29Ti medium1 Next Leading tau matches to tau20Ti medium1 Tau Trigger Reweighting Use TauSF from tau performance group recommendation SUSY Approval Meeting29

30. Datasets  Data : 20.69 fb -1, √s=8 TeV (JetTauEtmiss Stream)  Standard Model MC ： SUSY Approval Meeting30

31. Objects and Events Selection SUSY Approval Meeting31

32. Overlap removal SUSY Approval Meeting32

33. m T2 without MET cut SUSY Approval Meeting33 b-veto m T2 b-veto jet-veto m T2 jet-veto

34. Systematic Uncertainty of QCD+W estimation Correlation between tauid and m T2 : difference between high mT2 region and low mT2 region high m T2 : 40 GeV< m T2 < 90 GeV low m T2 : m T2 < 40 GeV transfer factor difference: T_W : from MC f_W: from fitting on W MC m T2 distribution W fraction in region A: 17% Non QCD/W backgrounds in region A Systematic uncertainty taken from background study Statistic uncertainty in region A SUSY Approval Meeting34

35. W fraction estimation SUSY Approval Meeting35 OS-mT2 OS-mT2 -nobjet

36. The result of fake tau background estimation SUSY Approval Meeting36

37. mt2 distribution of alternative ABCD method SUSY Approval Meeting37

38. Correlation between tauid and mt2 in alternative ABCD method SUSY Approval Meeting38

39. Results from alternative ABCD method SUSY Approval Meeting39

40. Result with alternative JVF Cut(>0.25) SUSY Approval Meeting40

41.  D: SR (medium + tight tau, mT2>90GeV)  A: Top/Z/Diboson Control Region: close to SR except using loose tauID and remove met cut  CB: Normalization Region, close to D,A except 40<mT2<80GeV for OS mT2 region  We can extrapolate from Top/Z/Diboson Control region A to signal region D trough a transfer factor from C/B: D = A* C/B AD BC LooseMedium Tau ID MT2 Signal Region Top/Z/Diboson Control Region 2012/11/20 41 ABCD-like method Normalization Region SUSY BG Meeting

42. mt2 distribution of Z+jets SUSY Approval Meeting42

43. Z+jets mt2 fit SUSY Approval Meeting43

44. Z+jets systematic uncertainty: mt2 jet-veto SUSY Approval Meeting44

45. Z+jets systematic uncertainty: mt2 b- veto SUSY Approval Meeting45

46. mt2 distribution of top SUSY Approval Meeting46

47. mt2 fit of top SUSY Approval Meeting47

48. Top estimation systematic uncertainty : mt2 jet-veto SUSY Approval Meeting48

49. Top estimation systematic uncertainty : mt2 b-veto SUSY Approval Meeting49

50. Diboson samples and events number(raw number) in SR SUSY Approval Meeting50

51. Diboson systematic uncertainty : mt2 jet-veto SUSY Approval Meeting51

52. Diboson systematic uncertainty : mt2 b-veto SUSY Approval Meeting52

53. ABCD-like diboson estimation SUSY Approval Meeting53

54. Acceptance of at least two taus for pMSSM 54SUSY Approval Meeting

55. Acceptance of at least two taus for modeA/C 55SUSY Approval Meeting

56. Signal Optimisation Signal Region – SR@OSmt2  mt2>90GeV – SR@OSmt2-nobjet  mt2>100GeV Signal Mode – Pmssm – Simplified modeA – Simplified modeC 56SUSY Approval Meeting

57. Signal Optimization Background estimation in Signal region: – The number of events with 5 fb-1 are scaled to 20.69 fb-1. – Systematical uncertainty is quoted as 15%. 57SUSY Approval Meeting

58. SR opt with 5fb-1 data @OSMT2 modeA modeC pMSSM  Data (5fb-1)  Mt2>80GeV: 3  Mt2>90GeV: 2  Mt2>100GeV: 1 Mt2>80GeV Mt2>90GeVMt2>100GeV 58SUSY Approval Meeting

59. SR opt with 5fb-1 data @OSMT2-nobjet modeA modeC pMSSM  Data (5fb-1)  Mt2>80GeV: 20  Mt2>90GeV: 4  Mt2>100GeV: 2 Mt2>80GeV Mt2>90GeVMt2>100GeV 59SUSY Approval Meeting

60. Zn check for two modeA grids OSmt2 modeA mt2>80@ C1 = 150 N1 = 50 s = 23.3351 b = 11.9228 significance = 4.51045 mt2>90@ C1 = 150 N1 = 50 s = 18.8384 b = 7.94852 significance = 4.51581 mt2>100@ C1 = 150 N1 = 50 s = 16.2078 b = 3.97426 significance = 5.20883 mt2>80@ C1 = 250 N1 = 100 s = 9.86776 b = 11.9228 significance = 2.10468 mt2>90@ C1 = 250 N1 = 100 s = 6.83389 b = 7.94852 significance = 1.83262 mt2>100@ C1 = 250 N1 = 100 s = 4.65025 b = 3.97426 significance = 1.76165 OSmt2-nobjet modeA mt2>80@ C1 = 150 N1 = 50 s = 41.1117 b = 79.4852 significance = 2.35261 mt2>90@ C1 = 150 N1 = 50 s = 32.6729 b = 15.897 significance = 5.19816 mt2>100@ C1 = 150 N1 = 50 s = 24.8696 b = 7.94852 significance = 5.65192 mt2>80@ C1 = 250 N1 = 100 s = 18.947 b = 79.4852 significance = 1.10004 mt2>90@ C1 = 250 N1 = 100 s = 12.4417 b = 15.897 significance = 2.23432 mt2>100@ C1 = 250 N1 = 100 s = 9.16587 b = 7.94852 significance = 2.41341 60SUSY Approval Meeting

61. Expected signal yields(21fb-1) SR@OSmt2: pMSSM 61SUSY Approval Meeting

62. Expected signal yields(21fb-1) SR@OSmt2-nobjet: pMSSM 62SUSY Approval Meeting

63. Signal yields at x/y axis (OSmt2) RunNb=164475 mu=100;M2=100 signal yield=0+0 RunNb=164476 mu=110;M2=100 signal yield=39.9135+26.3983 RunNb=164477 mu=120;M2=100 signal yield=40.9171+25.6674 RunNb=164478 mu=140;M2=100 signal yield=16.2225+15.4187 RunNb=164479 mu=160;M2=100 signal yield=0 RunNb=164480 mu=180;M2=100 signal yield=0 RunNb=164481 mu=210;M2=100 signal yield=0 RunNb=164482 mu=250;M2=100 signal yield=0 RunNb=164483 mu=300;M2=100 signal yield=0 RunNb=164484 mu=350;M2=100 signal yield=0 RunNb=164485 mu=400;M2=100 signal yield=0 RunNb=164486 mu=450;M2=100 signal yield=0 RunNb=164487 mu=500;M2=100 signal yield=0 RunNb=164488 mu=100;M2=110 signal yield=0 RunNb=164501 mu=100;M2=120 signal yield=50.8324+27.6802 RunNb=164527 mu=100;M2=160 signal yield=1.46859+3.08171 RunNb=164540 mu=100;M2=180 signal yield=6.33867+6.13021 RunNb=164553 mu=100;M2=210 signal yield=13.1495+8.33708 RunNb=164566 mu=100;M2=250 signal yield=4.85258+4.5601 RunNb=164579 mu=100;M2=300 signal yield=27.8572+11.0293 RunNb=164592 mu=100;M2=350 signal yield=9.70794+7.27852 RunNb=164605 mu=100;M2=400 signal yield=0 RunNb=164618 mu=100;M2=450 signal yield=0 RunNb=164631 mu=100;M2=500 signal yield=0 63SUSY Approval Meeting

64. Expected signal yields(21fb-1) OSmt2-jetveto(left) / OSmt2-bjetveto(right) modeA modeC modeA modeC 64SUSY Approval Meeting

65. Cross-section upper limits for Dstau samples A rough idea of the value. More will be done soon. Better exclusion cross-section upper limits is provided by OSmt2 jet veto SR. 65SUSY Approval Meeting

66. 164604:mu=500,M2=350 Cut 0 : 10000 no cut Cut 1 : 10000.000977 GRL cut Cut 2 : 10000.000977 LAr hole veto + TTC incomplete event veto Cut 3 : 9953.8867188 jet cleaning + LarError cut Cut 4 : 9868.9423828 >= 1 primary vertex with >4 tracks Cut 5 : 9735.7275391 cosmic muon veto+ Bad muon veto Cut 6 : 3053.902832 at least 2leptons Cut 7 : 822.21057129 tau-tau (pt>40,25GeV or MET>150GeV) *** Cut 8 : 430.58502197 tau-tau with trigger match Cut 22 : 78.932563782 //SR4: OS && jet veto &&Z veto && MET>40 Cut 24 : 30.94043541 && mT2_new > 90 *** Cut 25 : 224.74725342 SR5:OS && bjet veto && zveto Cut 26 : 185.11817932 && MET>40GeV Cut 27 : 49.082584381 && mT2 > 100 GeV SUSY Approval Meeting66

67. 164602:mu=400,M2=350 Cut 0 : 10000 no cut Cut 1 : 10000.000977 GRL cut Cut 2 : 10000.000977 LAr hole veto + TTC incomplete event veto Cut 3 : 9963.6582031 jet cleaning + LarError cut Cut 4 : 9873.9707031 >= 1 primary vertex with >4 tracks Cut 5 : 9744.5654297 cosmic muon veto+ Bad muon veto Cut 6 : 3345.3520508 at least 2leptons Cut 7 : 819.33990479 tau-tau (pt>40,25GeV or MET>150GeV) *** Cut 8 : 480.61099243 tau-tau with trigger match Cut 22 : 77.047554016 //SR4: OS && jet veto &&Z veto && MET>40 Cut 24 : 18.065355301 && mT2_new > 90 *** Cut 25 : 220.07788086 SR5:OS && bjet veto && zveto Cut 26 : 177.69471741 && MET>40GeV Cut 27 : 34.182556152 && mT2 > 100 GeV SUSY Approval Meeting67

68. Exclusion Limits – mode A SUSY Approval Meeting68  Masses of degenerate and are excluded up to 300-330 GeV in the chargino-neutralino simplified model for light (below 50-100 GeV)

69. Exclusion Limits – mode C SUSY Approval Meeting69  In the chargino-chargino simplified model, we exclude masses of 200< <330GeV for very light ( below 30-50GeV)

70. Exclusion Limits - pMSSM Holes formed due to relatively lower signal yield with higher statistical err. SUSY Approval Meeting70