1 / 15

Tagging b-jets with ’s

Tagging b-jets with ’s. Jet Reconstruction Muon Reconstruction Tagging variables MC distribtions Reco distributions Efficiency / purity Overall efficiency and purity Outlook. Some definitions / data files. ttbar, 4000 events reconstructed with p08.01.00 SAM project:

lucia
Download Presentation

Tagging b-jets with ’s

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. Tagging b-jets with ’s • Jet Reconstruction • Muon Reconstruction • Tagging variables • MC distribtions • Reco distributions • Efficiency / purity • Overall efficiency and purity • Outlook B-ID Vertical review - muonTag O. Peters

  2. Some definitions / data files • ttbar, 4000 events • reconstructed with p08.01.00 • SAM project: • stage_reco_pythia_ttbar_incl_p05_p08.01.00 • Efficiency = • Purity = • Taggable jet = Reco’d jet with b decaying to reco’d muon B-ID Vertical review - muonTag O. Peters

  3. Jet reconstruction • 0.5 Cone size has greatest efficiency/resolution B-ID Vertical review - muonTag O. Peters

  4. Muon reconstruction • Reconstruction in jets less precise • Tails caused by mismatch of local muon track to Gtrack • Current matching criteria are ‘loose’ • Need tighter matching, better reconstruction B-ID Vertical review - muonTag O. Peters

  5. Backgrounds for b-jets • Punch-trough /K’s • In-flight /K   decay • W   with associated jets (ttbar) •    with associated jets B-ID Vertical review - muonTag O. Peters

  6. Tagging variables • Currently using: • R - only muons with R < 0.7 considered • PTRel • P / Ejet • Possible other tagging variables: • DCA of muon • PLRel • PTRel significance B-ID Vertical review - muonTag O. Peters

  7. PTRel • PT relative to jet-axis • PTRel = MC distributions B-ID Vertical review - muonTag O. Peters

  8. PTRel Reco Variables B-ID Vertical review - muonTag O. Peters

  9. PTRel Efficiency & Fake rate B-ID Vertical review - muonTag O. Peters

  10. P / Ejet - MC B-ID Vertical review - muonTag O. Peters

  11. P / Ejet - Reco B-ID Vertical review - muonTag O. Peters

  12. P / Ejet - Efficiency & Fake rate B-ID Vertical review - muonTag O. Peters

  13. Overall efficiency & purity • Using cuts: • 1 < PTRel < 5 • 0.15 < P / Ejet < 0.5 • Taggable bjets: 511, tagged: 143 (27%) • Background: 332, tagged: 42 (13%) B-ID Vertical review - muonTag O. Peters

  14. Outlook • Muon reconstruction in jets needs work • Need to investigate broader PT spectrum • Other tagging variables need implementation B-ID Vertical review - muonTag O. Peters

  15. Short term physics? • Coming month will give muons + jets • No precise muon PT measurement • Can we measure some b-jet cross section? B-ID Vertical review - muonTag O. Peters

More Related