1 / 70

Performance and physics results for Phase1 upgrade

Performance and physics results for Phase1 upgrade. Alessia Tricomi (University and INFN Catania ) o n behalf of the Tracker Upgrade Simulation Group. Performance studies. The g oal for the TDR was to show improvement in Physics cases and robustness of the new design .

satin
Télécharger la présentation

Performance and physics results for Phase1 upgrade

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Performance and physics results for Phase1 upgrade Alessia Tricomi (University and INFN Catania) on behalf of the Tracker Upgrade Simulation Group

  2. Performance studies • The goal for the TDR wasto show improvement in Physics cases and robustness of the new design. • Focus on relative improvement of the upgrade wrt current geometry. • Two complementary approaches: • Show improvements in basic building blocks for physics using a full (Geant) simulation of the upgrade • Demonstrate improvements in tracking efficiency and fake rate • Demonstrate improved IP resolution and b-tagging performance • Improvements in relevant physics channels (under PC responsibility) Pixel Upgrade Meeting Alessia Tricomi

  3. Pixel Upgrade dictionary • Current Detector: • Current pixel detector geometry (3 barrel layers, 2 disks) • Current beam pipe • Dedicated “SLHC” release CMSSW_4_2_8_SLHC2 to use Design/Ideal conditions and same configurations/settings for tracking • Phase1 Upgrade (R30F12) geometry: • Upgrade geometry with 4 BPIX layers and 3 endcapdisks • First barrel layer at R=30 with 12 faces • New detailed material description according to PSI drawings • New beampipe (Sunanda) implemented • CMSSW_4_2_8_SLHCtk + 520 backporting Pixel Upgrade Meeting Alessia Tricomi

  4. Upgrade Studies • Study at • 2×1034 cm-2s-1 at 25ns (50ns),<PU>=50 (100) • 1×1034 cm-2s-1 at 25 ns,<PU>=25 • zero PU • Dynamic data loss (due to pixel ROC) used in simulations • Tracking steps modified for upgrade geometry and high PU • Using CMSSW_4_2_8 but with 5_2_0 tracking backported • Dropped detached tracking steps (see backup slides) • Used regular CMS DQM validation packages to get tracking and b-tagging performance plots • Fullsim, 14 TeV, ideal conditions, no pixel CPE templates used • ttbar from PYTHIA (10K events) • Muon gun (10K events-4 muons/event, generated flat in pT and eta, 200k events-ten muons/event, generated flat in p and eta) Pixel Upgrade Meeting Alessia Tricomi

  5. Data loss for Upgrade Studies • Peak luminosity values Pixel Upgrade Meeting Alessia Tricomi

  6. Upgrade Iterative Tracking (Stdgeom) • 5_2_0 tracking for current pixel geometry (from “2012 tune”) • Close to 5_2_0 tracking, use steps 0-2, and 4A (for high eta) • Reduce step 4A d0 cut to reduce CPU and memory usage Release CMSSW_4_2_8_SLHCstd2_patch1 Tracking steps Pixel Upgrade Meeting Alessia Tricomi

  7. Upgrade Iterative Tracking (Phase 1) • 5_2_0 tracking for Phase 1 geometry (not optimized) • Make close to 5_2_0 tracking, use steps 0-2, and 4A, add step “-1” • Step 3 (pixel pairs) to recover efficiency in eta ~1.2–1.4 region Release CMSSW_4_2_8_SLHCtk3_patch1 Tracking steps Pixel Upgrade Meeting Alessia Tricomi

  8. Reduced material even with more layers Pixel Upgrade Material Budget 50% less photon conversion in/before pixel at eta 1.5 Rad. Len. Nucl. Int. Len. Pixels Pixels Dots – Upgrade Green – Currgeom Pixel Upgrade Meeting Alessia Tricomi

  9. Object performance Transverse and Longitudinal IP Primary Vertex Tracking Btagging Robustness Pixel Upgrade Meeting Alessia Tricomi

  10. Impact Parameter Resolutions • Transverse: muon sample (10 muons/event), zero pileup • Generated flat in E and eta (plot vs absolute p and in 4 eta regions) • Compare current and upgrade detectors (modified MTV) Pixel Upgrade Meeting Alessia Tricomi

  11. Impact Parameter Resolutions • Longitudinal: muon sample (10 muons/event), zero pileup • Generated flat in E and eta (plot vs absolute p and in 4 eta regions) • Compare current and upgrade detectors Pixel Upgrade Meeting Alessia Tricomi

  12. Impact Parameter Resolutions • Transverse: muon sample (10 muons/event), <PU>=50 • Generated flat in E and eta (plot vs absolute p and in 4 eta regions) • Compare current and upgrade detectors Pixel Upgrade Meeting Alessia Tricomi

  13. Impact Parameter Resolutions • Longitudinal: muon sample (10 muons/event), <PU>=50 • Generated flat in E and eta (plot vs absolute p and in 4 eta regions) • Compare current and upgrade detectors Pixel Upgrade Meeting Alessia Tricomi

  14. Primary Vertex Resolution • ttbar sample, zero PU and <PU>=50 Pixel Upgrade Meeting Alessia Tricomi

  15. Tracking in ttbar ttbar sample, High purity pT> 0.9 GeV/c Pixel Upgrade Meeting Alessia Tricomi

  16. Tracking with muons • Muonsample • High purity • pT>1 GeV/c • numtracking layers with hits >= 8 Pixel Upgrade Meeting Alessia Tricomi

  17. Tracking Efficiency/Fake Rate • ttbar sample, compare current and upgrade detectors • High purity, pT > 0.9 GeV/c Pixel Upgrade Meeting Alessia Tricomi

  18. Tracking vs PU • Average tracking efficiencies vs PU • ttbar, high purity tracks, pT > 0.9 GeV/c Pixel Upgrade Meeting Alessia Tricomi

  19. Tracking vs PU • Average track fake rates vs PU • ttbar, high purity tracks, pT > 0.9 GeV/c Pixel Upgrade Meeting Alessia Tricomi

  20. B-tagging Performance • ttbar, CSV tagger, compare current and upgrade • ak5PFjets PFnoPU, jet pT > 30 GeV, DUS ,c,b jets 15% absolute gain in b jet efficiency for 1% fake rate Pixel Upgrade Meeting Alessia Tricomi

  21. B-tagging Performance • ttbar, CSV tagger, compare current and upgrade, <PU>=100 • ak5PFjets PFnoPU, jet pT > 30 GeV, DUS ,c,bjets Improvement even more impressive at 100 PU Pixel Upgrade Meeting Alessia Tricomi

  22. B tagging performance • Upgrade as good or better at high pileup as current at low pileup Upgrade PU50 Current PU0 Upgrade PU50 Current PU25 Pixel Upgrade Meeting Alessia Tricomi

  23. B-tagging Performance vs PU • ttbar, CSV tagger, compare current and upgrade, <PU>=50 • ak5PFjets PFnoPU, jet pT > 30 GeV, DUS,b jets • Much better handling high Pile-Up Pixel Upgrade Meeting Alessia Tricomi

  24. Robustness: BPIX1 Inefficiency Study • Vary inefficiency of BPIX layer 1: 0%, 5%, 10%, 20% • All other layers at 100% • ttbar, <PU>=50, light quark mis-tag=1% • Upgrade detector more robust to BPIX1 inefficiency Pixel Upgrade Meeting Alessia Tricomi

  25. Robustness: BPIX1 Inefficiency Study • Vary inefficiency of BPIX layer 1: 0%, 5%, 10%, 20% • All other layers at 100% • ttbar, <PU>=50, high purity tracks, pT>0.9 GeV/c • Upgrade detector more robust to BPIX1 inefficiency Pixel Upgrade Meeting Alessia Tricomi

  26. TIB Inefficiency Study • Switch off certain modules (in black below) • List provided by Frank Hartmann • Or consider a uniform 20% inefficiency in TIB1,2 Pixel Upgrade Meeting Alessia Tricomi

  27. Robustness to TIB degradation With Dead Modules Upgrade detector more robust wrt TIB loss With 20% uniform inefficiency in TIB1,2 Pixel Upgrade Meeting Alessia Tricomi

  28. Small pixel scenario: tracking with ttbar at 100PU BPIX Layer1: pixel size 75x100 mm2, 220 mm thickness ROC threshold 1200 e- instead of 2000 Significant improvement at 100 PU wrt Upgrade Phase1 detector Good news towards Phase2 Pixel Upgrade Meeting Alessia Tricomi

  29. Small pixel scenario: btagging performance BPIX Layer1: pixel size 75x100 mm2, 220 mm thickness ROC threshold 1200 e- instead of 2000 No data loss Significant improvement at 100 PU wrt Upgrade Phase1 detector Good news towards Phase2 Pixel Upgrade Meeting Alessia Tricomi

  30. Physics Performance ZHllbb HZZ4l SUSY MT2 SUSY gg+MET All analysis show relative improvement and have not been optimized/retuned for high PU Pixel Upgrade Meeting Alessia Tricomi

  31. ZHllbb • Analysis based on: • triggering on lepton events; • kinematic reconstruction of Z from isolated dileptons; • reconstructing invariant mass from two b-tagged jets; • multivariate final variable • Higher muon/electron ID efficiency helps with (1-2), better b-tagging helps with (3-4) • Compare relative performance of current detector and upgrade at 14 TeV with 50 pileup events Pixel Upgrade Meeting Alessia Tricomi

  32. ZHmmbb event selection Pixel Upgrade Meeting Alessia Tricomi

  33. ZHmmbb cut flow Values greater than 1 show increased efficiency for the Phase1 upgrade and vice versa Pixel Upgrade Meeting Alessia Tricomi

  34. ZHeebb event selection • Same selection as for muons but • Electrons use 95% working-point of VBTF • Isolation is relaxed as in the di-muonanalysis • Dimuon mass ~2 GeV high, so Z mass cut increased by +2 GeV like in dimuonanalysis • Other criteria same as for di-muon channel Pixel Upgrade Meeting Alessia Tricomi

  35. ZHeebb cut flow Values greater than 1 show increased efficiency for the Phase1 upgrade and vice versa Pixel Upgrade Meeting Alessia Tricomi

  36. ZHllbb results • ZHmmbb • 65% relative gain in signal efficiency for di-muon channel • 75% gain with single muonHLT • 175% gain with dimuonHLT (upgrade detector barely affected by the three pixel hit requirement) • ZHeebb • 65% relative gain in signal efficiency for di-electron channel • Not enough MC to properly estimate total reductions in backgrounds Pixel Upgrade Meeting Alessia Tricomi

  37. HZZ4l • Analysis based on: • triggering on di-lepton events; • kinematic reconstruction of 2 Zs from isolated di-leptons; • reconstructing invariant mass of Higgs • Higher muon/electron ID efficiency helps with (1-2) • Compare relative performance of current detector and upgrade at 14 TeV with 50 pileup events Pixel Upgrade Meeting Alessia Tricomi

  38. HZZ4l event selection • Using same cuts as in 2012 analysis (HIG-12-016) • PF leptons used • ElectronspT> 7 GeV, |η|<2.5; MuonspT > 5 GeV, |η| < 2.4 • Isolationrelaxedfrom 0.15 to 5.0 • |SIP3D|<4 for each lepton • 40 < mZ1<120 GeV; 12 < mZ2<120 GeV; ml+l->4GeV • m4l> 100 GeV • same HLT estimate as in ZH: 3+ pixel hits on trigger leptons Pixel Upgrade Meeting Alessia Tricomi

  39. HZZ4m cut flow 40% gain in 4m channel Values greater than 1 show increased efficiency for the Phase1 upgrade and vice versa Pixel Upgrade Meeting Alessia Tricomi

  40. HZZ4e cut flow 50% gain in 4e channel Values greater than 1 show increased efficiency for the Phase1 upgrade and vice versa Pixel Upgrade Meeting Alessia Tricomi

  41. HZZ2e2m cut flow 48% gain in 2e2m channel Values greater than 1 show increased efficiency for the Phase1 upgrade and vice versa Pixel Upgrade Meeting Alessia Tricomi

  42. SUSY MT2b analysis • Fully hadronic final states with large MET • B jets coming from cascade decay of gluino and squark to third generation sbottom, stop • SUSY particles identified through the discovery parameter MT2 • Tail of Supersimmetric Transverse Mass related to parent sparticle mass (endpoint) • Compare relative performance of current detector and upgrade at 14 TeV with 50 pileup events wrt to btagging improvement • Signal: LM9 benchmark point • Bkg: ttbar • See AN-2012/275 for details Pixel Upgrade Meeting Alessia Tricomi

  43. SUSY MT2b event selection • Good primary vertes • Veto electrons: pT>10 GeV/c; |η|<2.4; |d0|<0.04cm; |dz|<1.0cm; missing innerhits<2; PFIso<2.0 • Veto muons: pT>10 GeV/c; |η|<2.4; |d0|<0.04cm; |dz|<1.0cm; Trkhits>10; Pixhits>0; PFIso<2.0 • Jets: 2 PF jets with pT> 20 GeV/c passinglooseJetID; veto events with jets pT>50 GeV/c but failing jet ID • MET: PFMET>30GeV;PFH >750GeV • B-tag: Tight CSV tag > 0.898 Pixel Upgrade Meeting Alessia Tricomi

  44. SUSY MT2b analysis Before any b-tagging One b-jet required 20% higher signal selection efficiency can be obtained without any real optimization for the new detector and high pile-up. Pixel Upgrade Meeting Alessia Tricomi

  45. SUSY gg+MET analysis • Di-photon events+MET signature for SUSY • No significant SM bkg, small contribution from Vgg • Main bkg comes from fake MET • See AN-2012/269 • Same 14 TeV, 50 pileup scenario as others • Main improvement comes from fake rate reduction Pixel Upgrade Meeting Alessia Tricomi

  46. SUSY gg+MET analysis • Events divided in four classes: gg, ge, ee, fake-fake • ge and ee samples used to estimate fake rate by fitting Z peak Pixel Upgrade Meeting Alessia Tricomi

  47. SUSY gg+MET analysis • Fake rate 7.0% for the current detector and 1.25% for Phase1 pixel detectors • Fake rate with the upgrade detector at 50 PU is comparable with the performance of the current detector in low luminosity run Pixel Upgrade Meeting Alessia Tricomi

  48. Conclusions • All results show that the new detector at high PU performs as well or even better than the current detector at low luminosity • The results also show that the new detector is fairly robust against possible inefficiency in BPIX1 and TIB1,2 • All the results have been approved by Tracking/btagging/Physics group – PAS SUS-12-020 • Improvements from the new design are broad and substantial and will have a significant impact our physics program • Still a lot of work to be done to tune algorithms and analysis for high PU scenario • Stay tuned! Pixel Upgrade Meeting Alessia Tricomi

  49. Back-up slides Pixel Upgrade Meeting Alessia Tricomi

  50. Tracking for Upgrade Studies • Use 4_2_8 but with 5_2_0 tracking, and drop detached trks • Fullsim, 14 TeV, ideal conditions, no pixel templates • Regular CMS validation package, current and upgrade pixel det Regular 5_2_0 Tracking steps Pixel Upgrade Meeting Alessia Tricomi

More Related