1 / 6

Wgam/Zgam Xsec calculation

Wgam/Zgam Xsec calculation. Zhijun Liang University of Oxford. Wgam/Zgam NLO predictions using MCFM. MCFM 6.1 is used to predict Wγ/Zγfiducial cross section in Parton level. I nput card example: /afs/cern.ch/user/z/zliang/public/forCMS/input.DAT. 1fb-1 Wgamma/Zgamma paper

kennethphillips
Download Presentation

Wgam/Zgam Xsec calculation

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. Wgam/Zgam Xsec calculation Zhijun Liang University of Oxford

  2. Wgam/Zgam NLO predictions using MCFM • MCFM 6.1 is used to predict Wγ/Zγfiducial cross section in Parton level. • Input card example: • /afs/cern.ch/user/z/zliang/public/forCMS/input.DAT 1fb-1 Wgamma/Zgamma paper arXiv:1205.2531

  3. Parton /particle level predictions • (Parton level): predicted by MCFM. • Particle level: • Measure the scale factor using Alpgento correct for parton to particle level • Correct for jet definitions difference between two levels. • Correct for photon isolation difference between two levels. 1fb-1 Wgamma/Zgamma paper arXiv:1205.2531

  4. Backup

  5. ATLAS Vs CMS • Photon isolations (using relative isolation e_h) • CMS : e_h<0.15 (harder cut on photon isolation) • ATLAS : e_h<0.5 • The difference in these choice is less than 5% • Kinematics selections: • ATLAS : fiducial regions ( with all pT/eta cuts ) • CMS : Total phase space regions. • phase space without lepton pT/eta cut • Photon pT>15GeV , no eta cuts • Renormalization /fragmentation scale • CMS : dynamic scale • ATLAS : fixed scale on W (or Z) mass for Wγ or Zγ. • The difference between these two choice is very small (<2%). • CMS MCFM input cards are for total cross section • /afs/cern.ch/user/p/poter/public/VG_MCFM/input.DAT • ATLAS MCFM input cards are for fiducial cross section • /afs/cern.ch/user/z/zliang/public/forCMS/input.DAT

  6. Only compare MCFM the inclusive cross section prediction • CMS input cards are for total cross section • /afs/cern.ch/user/p/poter/public/VG_MCFM/input.DAT • ATLAS input cards are for fiducial cross section • /afs/cern.ch/user/z/zliang/public/forCMS/input.DAT MCFM Input card Comparison ATLAS input cards CMSinput cards

More Related