Updates on Conversions in H Updates on Conversions in H Henso - PowerPoint PPT Presentation

γγ → γγ Updates on Conversions in H → Updates on Conversions in H Henso ABREU , Jean-François MARCHAND ( LAPP ) discussions with J,B. DE VIVIE, M. ESCALIER, L. FAYARD, F. POLCI ( LAL ), M.FANTI ( INFN ) and T. KOFFAS ( CERN ) Meeting e/ γ 21/01/2009 Meeting e/ γ 27/02/2009

Introduction Dataset used • mc08.106384.PythiaH120gamgam.recon.AOD.e352_s462_r541 • 38471 Events Goal of this study • Compute the signal, secondary and fake rates for single and double track conversions ATLAS-LAL General Meeting 2 26/02/2009

Remember my last presentation Cuts Pt (gamma)>25 GeV itune2 + PtIsolationCone < 4GeV Pt γ γ 1 >40 GeV and Pt γ γ 2 > 25GeV γ γ γ γ ATLAS-LAL General Meeting 3 Double track No TRTSA 26/02/2009 conversions

Remember my last presentation Cuts Single track Pt (gamma)>25 GeV itune2 + PtIsolationCone < 4GeV conversion Pt γ γ γ γ 1 >40 GeV and Pt γ γ γ γ 2 > 25GeV ATLAS-LAL General Meeting 4 26/02/2009

Reco to truth matching Definitions True converted photon = True e - / e + pair with same vertex • False converted photon = e + / e + pair with different vertex for each • particle or pair of 2 other particles ( e + / e + , e - / e - , π ± / e ± , π ± / π ± …) Looking up the fifteenth mother of each true particle associated to conversion vertices ATLAS-LAL General Meeting 5 26/02/2009

Reco to truth matching “Signal” = Converted photon with true conversion coming from H e + γ H e - “Secundary” = True converted photon coming from Higgs ( after bremsstrahlung ) Or False conversion but at least one of the track is coming from Higgs e + e + e - π ± e - e + γ e - e + e - e ± H Multiple bremsstrahlung e - γ e - γ “Fakes” = True converted photon not coming from Higgs OR false converted photon not coming from Higgs e + e + e + e - π ± γ π 0 , η , ω … or e - e + e - e ± e - ATLAS-LAL General Meeting 6 26/02/2009

Example of secundary converted photon from Higgs e - e + Pt = 1.3 GeV. Pt = 5.1 GeV. 7 Rconv,Zconv = (195.28,-558.12) Pt = 0.3 GeV Pt = 6.4 GeV e - Pt = 0.10 GeV e - e - 6 Pt = 1,9 GeV. Rconv,Zconv = (140.69,-412.35) Pt = 13.0 GeV e - Pt = 8.353 GeV. Rconv,Zconv = (140.3,-411.36) 5 e - Pt = 8.63 GeV. Rconv,Zconv = (127.80,-377.93) 4 Pt = 3.3 GeV e - Pt = 9.65 GeV. Rconv,Zconv = (124.28,-368.51) 3 Pt = 22.6 GeV. Rconv,Zconv = (124.25,-368.45) 2 e + e - 1 7 Pt = 25.9 GeV. Rconv,Zconv = (91.1,-279.14) Pt = 34.4 GeV 5,6 2,3,4 H Pt = 64.3 GeV 1 Rconv,Zconv = (2.9336,-29.43)

Single Conversion p T γ γ γ > 25GeV γ p T γ γ > 25GeV γ γ Signal 75.67 % Single track Secundary 3.22 % conversion Fakes 21.11 % • Peak at 0 mainly due to fakes ATLAS-LAL General Meeting 8 26/02/2009

Single Conversion p T γ γ γ > 25GeV , isEm, isolation γ p T γ γ γ γ > 25GeV,isEM, isolation Signal 76.04 % Single track Secundary 2.82 % conversion Fakes 21.13 % • Peak at 0 due to fakes ATLAS-LAL General Meeting 9 26/02/2009

Double track conversions p T γ γ > 25GeV γ γ Signal 88.08 % Double track Secundary 6.75 % conversions Fakes 5.17 % p T γ γ > 25GeV,isEM, isolation γ γ Signal 93.95 % Double track Secundary 5.78 % conversions Fakes 0.27 % ATLAS-LAL General Meeting 10 26/02/2009

Summary to each category of conversions • tid26567 e352s462r541 mc08 10 TeV reco 14.2.20.3 • tid32800 e322s483r562 valid1 14TeV reco 14.2.25.2 • 10.000 Events Photon recovery from photon container “C2” tid26567 tid32800 p T γ γ γ > 25GeV γ .2655 ± ± ± ± .0022 .2962 ± ± ± .0046 ± p T γ γ γ > 25GeV,isEM γ .1646 ± ± ± ± .0019 .1825 ± ± ± .0039 ± Double track conversions p T γ γ γ γ > 25GeV,isEM, isolation .1616 ± ± ± .0019 ± .1790 ± ± .0038 ± ± Photon recovery from electron container “C12” tid26567 tid32800 p T γ γ γ > 25GeV γ .0992 ± ± ± ± .0015 .1326 ± ± .0034 ± ± Double track p T γ γ γ > 25GeV,isEM γ .0190 ± ± ± ± .0007 .0219 ± ± ± ± .0015 conversions p T γ γ > 25GeV,isEM, isolation .0183 ± ± .0007 .0203 ± ± .0014 γ γ ± ± ± ± ATLAS-LAL General Meeting 11 26/02/2009

Summary to each category of conversions Photon recovery from photon container “C1” tid26567 tid32800 p T γ γ > 25GeV γ γ .2254 ± ± ± ± .0021 .3145 ± ± .0046 ± ± p T γ γ > 25GeV,isEM .1647 ± ± .0019 .2400 ± ± .0043 Single track γ γ ± ± ± ± conversion p T γ γ γ γ > 25GeV,isEM, isolation .1601 ± ± ± .0019 ± .2341 ± ± ± ± .0042 Photon recovery from electron container “C11” tid26567 tid32800 p T γ γ > 25GeV γ γ .1096 ± ± ± ± .0016 .1200 ± ± .0032 ± ± Single track p T γ γ > 25GeV,isEM .0690 ± ± .0013 .0740 ± ± .0026 γ γ ± ± ± ± conversions p T γ γ γ γ > 25GeV,isEM, isolation .0673 ± ± ± .0013 ± .0724 ± ± .0025 ± ± Photon recovery from electron container “C21” tid26567 tid32800 with a TRT Standalone track associated p T γ γ > 25GeV .1738 ± ± .0019 .0653 ± ± .0025 γ γ ± ± ± ± Single track p T γ γ > 25GeV,isEM γ γ .1366 ± ± .0018 ± ± .0490 ± ± .0022 ± ± conversions p T γ γ γ > 25GeV,isEM, isolation γ .1344 ± ± ± .0018 ± .0483 ± ± .0022 ± ± ATLAS-LAL General Meeting 12 26/02/2009

No truth conversion found p(1) 3 p(2) 3 u(3) 3 d(4) 3 s(5) 3 d(6) 3 Pair e - /e - or e + /e + ( and indirectly coming from Higgs) H(9) 3 γ (10) 3 γ (11) 3 Barcode H(11) 2 true track Status reco track 2 e + γ (13) 1 γ (14) 1 reco track 1 e - e - (202215) 1 e + (202214) 1 ATLAS-LAL General Meeting 13 26/02/2009

Truth conversion found p(1) 3 p(2) 3 d(3) 3 g(4) 3 g(5) 3 g(6) 3 Pt=57GeV γ (11) 3 γ γ γ H(7) 3 e - e + γ (8) 3 γ (9) 3 H(10) 2 Barcode Status γ (12) 1 γ (13) 1 ATLAS-LAL General Meeting 14 26/02/2009

Conclusions The amount of fake double track converted photons becomes ≈ 0% • when identification / isolation cuts are applied • Identification / isolation cuts have no impact on “signal/ secundary/ fake” repartition for single track converted photons Still ≈ 21% of fake single track converted photons after identification • / isolation cuts • fake associated doesn’t mean fake photon: Lot’s of unconverted photons are reconstructed a as single track converted photon ATLAS-LAL General Meeting 15 26/02/2009

BACKUP ATLAS-LAL General Meeting 16 26/02/2009

Reco to truth matching ATLAS-LAL General Meeting 17 26/02/2009

Table of Conversions for dataset tid26567 Signal Secondaires Fakes ATLAS-LAL General Meeting 18 26/02/2009

Table of Conversions for dataset tid26567 ATLAS-LAL General Meeting 19 26/02/2009

Conversion Flag Tool : recover photons from electron container • Photon container : → Unconverted photons → Single track conversions : Flag = 1 → Double track conversions : Flag =2 • Electron container + ConversionFlagTool : 2 steps • First step : → Loop over the VxContainer and look at the conversions that have not been used by any Photon → Extrapolate the 2 tracks from the conversion in case of a double track conversion or the track from the conversion in case of a single track conversion → Try to match the extrapolated track to an EM cluster from the electron container → If matching OK : → If double track conversion : Flag=12 → If single track conversion : Flag=11 • Second step (if the electron has not been recovered by first step) : → If the trackParticle associated to the electron is a TRT standalone track : Flag = 21 Meeting H->gg 16/10/2008 ATLAS-LAL General Meeting 20 26/02/2009