1 / 15

Update on the analysis of fragmentation function components at LEP1

DELPHI week QCD Meeting 5 December 2000. Update on the analysis of fragmentation function components at LEP1. Oxana Smirnova Christina Zacharatou Jarlskog Thanks for suggestions to: Torbjörn Sjöstrand. Components of the Fragmentation Function. at Q = 91.2 GeV. Cuts for charged particles:

tender
Download Presentation

Update on the analysis of fragmentation function components at LEP1

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. DELPHI week QCD Meeting 5 December 2000 Update on the analysis of fragmentation function components at LEP1 Oxana Smirnova Christina Zacharatou Jarlskog Thanks for suggestions to: Torbjörn Sjöstrand

  2. Components of the Fragmentation Function at Q = 91.2 GeV

  3. Cuts for charged particles: Rf impact parameter < 5 cm z impact parameter <10cm/sinq track length > 50 cm 0.1 GeV < p < 50 GeV 11o < q <169o Dp/p < 100% Cuts for events: at least 5 tracks with p>0.2 GeV total energy > 15 GeV Ehem > 3 GeV 26o < qsphericity < 154o max pimbalance = 20 GeV Data Selection

  4. Raw Data Binning: • 40 channels in cosq • 22 channels in xp: - 10 bins of width 0.01 - 5 bins of width 0.02 - 2 bins of width 0.05 - 3 bins of width 0.1 - 2 bins of width 0.2

  5. Correction Factors Correction factors for detector acceptance and resolution, isr, secondary interactions and kinematic cuts: Track and event selection cuts as in data.

  6. Corrected Cross Sections (in 22 xp bins) For each bin: Combined data for all years:

  7. Extraction of fragmentation function components Weighting method

  8. Components by weighting

  9. Components by weighting and fitting (only statistical errors)

  10. The fragmentation effect 20 M events from Jetset7.4: • no shower • only 2-jet events

  11. A simple algorithm to compensate for the fragmentation effect • estimate hadron-quark angle from Jetset (no shower) • use estimate to smear hadron polar angle • fit data using smeared distributions

  12. FT from the algorithm

  13. FL from the algorithm

  14. c2 from the algorithm

  15. Summary • Analysis updated for 1992-1995 data at Z peak • Study with Jetset shows non-zero FL in the absence of gluons: attributed to the fragmentation effect • Algorithm implemented to estimate compensation: FL reduced significantly at xp below 0.1 • More factors to be taken into account...

More Related