Pi0 Polarizability Meeting Apr 17, 2020

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Revision as of 07:23, 21 April 2020 by Elton (Talk | contribs) (Minutes)

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Meeting Information

Meeting Time And Location

10:00 am ET (JLab time)

REMOTE

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Action Items

  1. ChiPT calculation to one loop with Coulomb photon (Svetlana and Aleks)
  2. Follow-up contact with Marc to request paragraph (Rory)

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Feedback from collaboration review
    1. Feedback from Barry / Tue Apr 14
      • Rory: The estimate of the incoherent is not easy, but should be uniform in Phi, so polarization is a valuable tool.
    2. Feedback from Joerg
      • We need to clarify that CPP will run with a Pb target and we need an estimate of the calorimeter trigger rate to insure that NPP can run concurrently with CPP. Ilya was volunteered for this task.
  4. Theory update
    1. Discussion with Serguei Gevorkyan / Mon Apr 13
  5. Experiment update
    1. GlueX-doc-4433 Eta background (Elton)
  6. Updates to collaboration draft
    1. Backgrounds to be simulated
      • Background hits
      • BGGEN (PYTHIA)
      • eta production (Elton)
      • Incoherent production (Elton)
      • Npipi
    2. Table of cross sections (Rory and Ilya)
      • Include references to relevant data
      • Add values used in the proposal
    3. Experiment optimization
      • Target position (Beni).. not yet
      • Generate angular distributions for some other targets to compare to Pb
    4. Significance of experiment
      • The expected uncertainties of the extracted gg->pi0pi0 cross section (Fig. 24 of proposal) need to be verified and studied more carefully
    5. Analysis of PRIMEX data
  7. Other business
  8. Next meeting

Minutes

Attending: Jose, Svetlana, Beni, Ilya, Rory, Alex, Mark, Elton.

  1. Announcements
  2. Action Items
  3. Feedback from collaboration review
    1. Feedback from Barry / Tue Apr 14
    2. Feedback from Joerg
  4. Theory update
    1. Discussion with Serguei Gevorkyan / Mon Apr 13
    2. The plan for additional theory requires substantial work. The precision that the polarizability may be extracted with a given cross section uncertainty is still a goal for Jose and Svetlana, but will take time. For the proposal, the will rely on the Dai/Pennington calculations. Calculations to improvements in the extraction will continue past the proposal submission.
  5. Experiment update
    1. GlueX-doc-4433 Eta background (Elton)
      • Rory: It would be nice to plot the elasticity, in addition to missing mass, for ease of comparison with other Primakoff experiments.
      • Many questions and discussion occurred during the presentation.
  6. The remaining part of the agenda was left tabled for Monday. Here are some notes from meeting on Monday Apr 20:
    1. Experiment optimization
      • Primex He4 first look: Media:npp_primexdata.pdf
        • Beni showed various distributions of interest, especially the 2pi mass spectrum with various cuts.
        • He finds that the energy balance cut is a key discriminator for background
      • NPP MC test with 6 and 8 GeV Beam energy: Media:npp_MC.pdf
        • Running the gen_2pi0_primakoff generator, Beni compared the output at 6 and 8 GeV, with various interesting results on angle and 2pi mass. Differences in the distributions are clearly visible; more work is needed to determine their effect on the final outcome of the experiment.
  7. Other business
  8. Next meeting
    • We will meet at 9:00 am on Monday to continue with Beni's presentation and discuss the strategy for completing the proposal.