Optics Meeting Mar 21 2023 230PM ET

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Attendance

Andrew, David, Tyler, Sayak, Ciprian, Zuhal, Bill, Paul S.

Minutes

1. (Vassu) Moved the sieve hole "71" to a much smaller radius. Can clearly see difference between the location of tracks from that hole at the GEMs between the nominal B field and the "worst" case field map. Unexpectedly, the shift was in the phi location, not the radial location of the hole's image (unlike the case when the hole was at the original larger radius). The shift is about 2 degrees, or shift in the azimuthal position of a whopping 32 mm. This is even bigger than the 5 to 8 mm radial shifts seen for other holes. This may be a very good diagnostic (i.e. azimuthally offset holes at small radius). Adjusted the nomenclature as well to match the spectrometer sector numbering - the "71" hole is in sector S1.
2. (Andrew) Update on adding hyperons to remoll. Previous work is collected on the DocDB: here [1]. Andrew has written down and checked the kinematics. With photoproduction, the max pion energy from hyperon decay is 3.3 GeV (Lambda) and 4.1 GeV (Sigma), which would nominally be in the acceptance, but of course would require endpoint of the bremss spectrum. To get pion into our acceptance (i.e. above about 1.5 GeV) would need photon energy of roughly 7 GeV or above. Andrew has gathered data for single hyperon photoproduction for much lower photon energies (i.e. in the resonance region). Can we safely extrapolate cross section to higher E_gamma? What about exicted hyperons (which can strongly decay to Lambda and Sigma, and then weakly decay) - will the initial polarization be retained? Do we have to worry about electroproduction? Perhaps we can assume photoproduction dominates, and use to bound initial estimates. Lots to ponder.
3. (David) There has been a request to move the meeting time to 2:00 pm. Will check to see if there are conflicts.

Meeting link information

Meeting URL

https://cwm.zoom.us/j/97259755403?pwd=WTRqVHJnZ3RQa1IwNHdMQjJuQm9FZz09

Meeting ID: 972 5975 5403

Passcode: 4937

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