1 / 80

Comparing Vertex from Z  μμ to the Remaining Tracks

Comparing Vertex from Z  μμ to the Remaining Tracks. August 21, 2014 Ryan Kelley. Introduction. Compare vertex of the Z  μμ Idea is to take the μ’s from the Z μ from primary interaction point used two μ tracks to form a vertex u sing KalmanVertexFitter

mercia
Download Presentation

Comparing Vertex from Z  μμ to the Remaining Tracks

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. Comparing Vertex from Z  μμ to the Remaining Tracks August 21, 2014 Ryan Kelley

  2. Introduction • Compare vertex of the Z  μμ • Idea is to take the μ’s from the Z • μ from primary interaction point • used two μ tracks to form a vertex • using KalmanVertexFitter • used remaining tracks with pT > (1.0, 0.5, 0) or |p| > (0.5,1.0, 2.0) to form another vertex • using KalmanVertexFitter • using TrimmedVertexFitter • using AdaptiveVertexFitter • compare the difference in X,Y,Z positions

  3. Selection • Used SEDWG PAT configuration 2_2_10 • Datasets: • /Zmumu/Summer08_IDEAL_V11_redigi_v2/GEN-SIM-RECO • 20K Events • Selection • μ's • pT > 10.0 GeV • GlobalMuonPromptTight (recommended by μ I.D. note) • χ2/dof < 10 • |d0| < 2 mm (designed to reject decays in flight and punch through) • nHits from track ≥ 11 • Z Candidates • Created Z’s from μ+μ- (from above mu’s) • mZ – 4ΓZ < mμ+μ- < mZ + 4ΓZ

  4. Several Fitting Option oob • The fitters now available are • The KalmanVertexFitter: the simple least-squares algorithm (uses all the tracks with a weight of 1) • The AdaptiveVertexFitter: iterative re-weighted KalmanFitter? which down-weights tracks according to their distance to the vertex • The TrimmedVertexFitter: conventional robust version of the Kalman fitter, which removes tracks incompatible with the vertex • The GaussianSumFitter: fitter using the non-Gaussian distributions of measurement errors • The AdaptiveGsfVertexFitter: a combination of the adaptive fitter and the Gaussian-sum fitter • The GSF fitters are designed for objects that use GSF error calculations (e.g. Electrons) • wouldn’t work for tracker Tracks (from the μ’s and general tracks) • https://twiki.cern.ch/twiki/bin/view/CMS/SWGuideVertexFitting

  5. Vertex formed from Tracks • Used all tracks not from the Z candidates’ μ’s with • pT > 1.0 GeV • pT > 500 MeV • |p| > 500 MeV • |p| > 1.0 GeV • |p| > 2.0 MeV • no pT cut

  6. Convergence of the Fits • Only looked at the first three types • GSF fitting primarily for electrons • KVF and AVF w.r.t BeamSpot (TVF not implemented in CMSSW) • Log scale • The TVF rejects tracks when they’re killing the fit  more invalid.

  7. Validity of the Fits

  8. χ2/dof of the Fits

  9. χ2/dof of the Fits (zoom)

  10. # d.o.f of Fits

  11. χ2 prob of Fits

  12. # Tracks Used

  13. Track Weights Used

  14. # Tracks Used vs # d.o.f

  15. # Tracks Used vs # d.o.f

  16. # Tracks Used vs # d.o.f

  17. # Tracks Used vs # d.o.f

  18. # Tracks Used vs # d.o.f

  19. # Tracks Used vs # d.o.f

  20. Vertex formed from Z’s • Used the two tracks not from the Z candidates’ μ’s with • Used KalmanVertexFitter since only two tracks and we want the weight always =1

  21. Validity and # d.o.f of vertex from Z candidates

  22. χ2/dof and χ2 prob. of vertex from Z candidates

  23. Delta = Track - Z • Used attribute (vx, vy, vz) to calculate • Δvx = vxtracks – vxz • Δvy = vytracks – vyz • Δvz = vztracks – vzz • Showing AVF results

  24. Δvx • Δvx = vxtracks – vxz • no pT on Tracks

  25. Δvx • Δvx = vxtracks – vxz • pT > 500 MeV on Tracks

  26. Δvx • Δvx = vxtracks – vxz • pT > 1.0 GeV on Tracks

  27. Δvx • Δvx = vxtracks – vxz

  28. Δvx • Δvx = vxtracks – vxz

  29. Δvx • Δvx = vxtracks – vxz

  30. Δvy • Δvy = vytracks – vyz • no pT on Tracks

  31. Δvy • Δvy = vytracks – vyz • pT > 500 MeV on Tracks

  32. Δvy • Δvy = vytracks – vyz • pT > 1.0 GeV on Tracks

  33. Δvy • Δvy = vytracks – vyz

  34. Δvy • Δvy = vytracks – vyz

  35. Δvy • Δvy = vytracks – vyz

  36. Δvz • Δvz = vztracks - vzz • no pT on Tracks

  37. Δvz • Δvz = vztracks - vzz • pT > 500 MeV on Tracks

  38. Δvz • Δvz = vztracks - vzz • pT > 1.0 GeV on Tracks

  39. Δvz • Δvz = vztracks – vzz

  40. Δvz • Δvz = vztracks - vzz • pT > 500 MeV on Tracks

  41. Δvz • Δvz = vztracks - vzz • no pT on Tracks

  42. Resolution = Track - Gen • Used attribute (vx, vy, vz) to calculate • Res vx = vxtracks – vxgen • Res vy = vytracks – vygen • Res vz = vztracks – vzgen • Showing AVF results

  43. Resolution vxTracks • Res vx = vxtracks - vxgen • no pT on Tracks

  44. Resolution vxTracks • Res vx = vxtracks - vxgen • pT > 500 MeV on Tracks

  45. Resolution vxTracks • Res vx = vxtracks - vxgen • pT > 1 GeV on Tracks

  46. Resolution vxTracks • Res vx = vxtracks – vxgen

  47. Resolution vxTracks • Res vx = vxtracks – vxgen

  48. Resolution vxTracks • Res vx = vxtracks – vxgen

  49. Resolution vytracks • Res vy = vytracks - vygen • no pT on Tracks

  50. Resolution vytracks • Res vy = vytracks - vygen • pT > 500 MeV on Tracks

More Related