May 5, 2009 Physics

Time: 11:00 EST/10:00 CST

• ESNET Number 8542553
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To do list from last meeting

• Next Steps:

1. look at the a2 mass peak - adjust cuts on the eta and pi0 masses
2. introduce Pythia background - skim off the wanted events by cutting on the total neutral energy (but we need to record the total number of events before skimming) - hd_filter is a good program example
3. cut on eta and pi0 masses, then look at the effect on the different angular distributions (i.e. Gottfried-Jackson angles, etc.)
4. look at difference between reconstructed and generated z position for less than 65 cm
5. look at single photon reconstruction efficiencies
6. adjust the error matrix for the BCAL (look in PID/DPhoton_factory.cc)
7. Gather all relevant DocDB documents and cross section publications at one spot on the Wiki.
8. After pruning the Pythia events, check generated vs. reconstructed energy in a plot.

Tentative Agenda

1. Status quo on where we left off (Blake)
2. Discussion (all)

Minutes

Attendees: Matt, Ryan, Mihajlo (IU), David (Jlab), Blake, Zisis (UofR)

1. Blake reports:
   1. updated the calibration in the repository (includes dark rate)
   2. the pi-0 work is currently on hold
   3. has had some problems with the new ROOT version on the IU cluster
2. Matt briefly discussed the 7x7 error matrix with the variance along the diagonal and covariant elements off diagonally. The work depends on a coordinate transformation from local to global system.
3. Blake will review all relevant documents on the portal, starting with the Software section of the Calorimetry Review (GlueX-doc-989 Calorimeter Simulations) as well as documents on cross sections and Pythia compiled by Alex. Their links should be gathered at one spot on the Wiki.
4. Fitting primer: Run a Google search on 'Paul Avery fitting'
5. Pythia filtering was discussed and Blake will apply a greater than 6 GeV neutral energy cut as well as cuts on eta-pi0. A plot of Egenerated vs Ereconstructed should be made to ensure our correlation is ok and we are not skewing anything.
6. The eta-pi0 should be removed from the Pythia sample and run separately as signal. Blake wil look at the a2 meson.
7. David: nothing to report on the parametric MC at this time.
8. Matt: CLEO work is ongoing on physics samples and their angular distribution. At present this is focused on the 3pi channel. PWA will be done. The hope is to extend the work to the eta-pi channel next.
9. Reconstruction meetings will resume their weekly frequency.