Weekly Minutes 2007-11-30

From PrimExWiki

Present

In person: Pawel Ambrozewicz, Ashot Gasparian, Sergey Gevorgyan, Mark Ito, Liyang Jiang, Xin Qiao Li
On phone: Dan Dale, Liping Gan, Tulio Rodrigues, Dan Sober

Meeting Page

Contents

Last Meeting's Minutes

We reviewed the minutes from the last meeting from Xin Qiao, without significant comment. Please note that Liyang graciously agreed to defer his presentation for yet another week because of today's full agenda.

Compton

Yelena summarized her results on the Compton cross section as presented in her DNP talk (PDF) from October. See her slides for details. Her results include all 5 GeV data. She will be working on the low energy data next.

Pawel reviewed his latest cross section plots. Most of the latest detailed news on his analysis was presented last week (see the minutes).

Xin Qiao presented comparisons of theoretical calculations (PowerPoint) of the total compton cross section including radiative effects. See his slides for details. His main thrust was to compare the BASES/SPRING calculation of Avto Tkakbladze with that Mykhailo Konchatnyi's program. He finds them in good agreement.

Pair Production

Dan summarized the status of the pair production analysis. The plot of cross section versus x = Ee / Eγ, smeared by a GEANT simulation, shows good agreement with Sasha's calculation except for very high x. The smearing is not perfect and where the cross section is rapidly varying it is sensitive to the amount of smearing. There may also be some errors with HyCal crystals. If problem region is eliminated he expects that there will be good agreement (at about 1%). Dan also mentioned that Aram defends his thesis on Wednesday.

Proposal

PAC Presentation

Ashot presented some preliminary slides for presenting our preliminary result (PowerPoint) and our request for more beam time (PowerPoint). See his slides for details. We had an extensive discussion of the number of days requested and their allocation among the various activities. We also discussed the choice of targets.

Proposal Text

Dan showed the current draft. We had a discussion of the structure of the proposal, specifically the relative sequence of the experimental description and the discussion of physics results from the 2004 run. We agreed that the main discussion of the results should follow the description of the experiment and that the π0, Compton, and pair productions results should be grouped in a single section.


Recorded by Mark Ito