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General:
The bi-weekly analysis meetings are held twice to accommodate all members who want to participate.
First Batch is every Thursday (bi-weekly):
EDT: 7 pm
FNAL: 6 pm
LANL: 5 pm
Tokyo: 8 am (the next day)
Second Batch is every Wednesday (bi-weekly):
EDT: 12 (noon)
FNAL: 11 am
LANL: 10 am
Zoom link: https://fnal.zoom.us/j/438821341
Thursday, March-29 7 pm meeting:
Main agenda:
- Sivers asymmetry extraction from MC events. Goal: Understand all step in the Sivers asymmetry extraction.
- List the critical issue in the analysis and assign the PIC (person in charge) for each issue.
Slide: https://seaquest-docdb.fnal.gov/cgi-bin/private/ShowDocument?docid=5362
Some of main discussions:
Issue 1: phi-s definition, reference frame and future improvement
There was a confusion about the best reference frame for Drell-Yan. I followed the E1039-Proposal which used the Collin-Sopper frame, but the definition of phi-s (the spin polarization vector angle) is not clear. Is Collin-sopper frame the best referance for Drell-Yan analysis? I quoted some reference in my slide. The NMSU group have also discussed this issue but the conclusion hasn't settled yet. In the meeting, we got two others good paper/literature for reference:
https://link.springer.com/article/10.1140/epjc/s10052-014-2769-7
http://wwwcompass.cern.ch/compass/notes_public/2010-2.pdf
There was also offline discussion with Kenichi about the paper Phys. Rev. D 79, 034005 (2009) by S. Arnold et all "Dilepton production from polarized hadron hadron collissions". The (preliminary) conclusion is the dilepton rest frame (Collins-Sopper frame) is the frame that we have to use.
There was also suggestion to put the phi-asymmetry correction to the Sivers extraction.
Issue 2: Is rate dependence affect asymmetry
The incoming proton beam intensity are not flat. Is the rate dependence affect the asymmetry? It is too early to put a conclusion but everybody agree that this issue worth to be investigated.
Issue 3: List and Assign
Part 2 of the meeting listed the critical issue needed to be addressed and assign (proposed) the PIC (Person in Charge). The issues are listed on the slide.