Difference between revisions of "Tracking-6-17-2021"

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(Agenda)
(Minutes)
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= Minutes =
 
= Minutes =
 
# Tracking
 
# Tracking
## [https://halldweb.jlab.org/wiki/images/5/5f/20210617.pdf MilleKs alignment]
+
## [https://halldweb.jlab.org/wiki/images/5/5f/20210617.pdf MilleKs alignment] (Keigo)
 +
## [https://github.com/JeffersonLab/halld_recon/issues/531 Apparent rotation of photon beam] (Alex): Alex reported on his recent observation of an apparent non-zero angle of the incoming photon beam with respect to the z axis, as reconstructed with the &pi;<sup>+</sup>&pi;<sup>-</sup>p final state. This angle has a linear energy dependence, which can be almost exactly reproduced in simulation by rotating all 4-vectors by 0.5mrad around x and 0.1mrad around y. Since the kinematic fit assumes the beam to come in along the z axis, this rotation also produces phi-dependencies in the momentum pulls, not unlike what we see in real data. As a real rotation of the photon beam with respect to the z axis is unlikely, we probably observe a global rotation of the GlueX coordinate system. It was suggested to supply this rotation to the kinematic fit for real data to check if it actually cures some of the peculiar behavior.
 
# Detector related reports
 
# Detector related reports
 
#* FA125  
 
#* FA125  

Revision as of 11:50, 18 June 2021

  1. Instructions for Bluejeans meeting connection
  2. Meeting ID: 290664653
  3. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Thu 6/17/2021 2pm

Agenda

  1. Tracking
  2. Detector related reports
    • FA125
    • CDC
    • FDC
  3. GEM-TRD
  4. Other

Minutes

  1. Tracking
    1. MilleKs alignment (Keigo)
    2. Apparent rotation of photon beam (Alex): Alex reported on his recent observation of an apparent non-zero angle of the incoming photon beam with respect to the z axis, as reconstructed with the π+π-p final state. This angle has a linear energy dependence, which can be almost exactly reproduced in simulation by rotating all 4-vectors by 0.5mrad around x and 0.1mrad around y. Since the kinematic fit assumes the beam to come in along the z axis, this rotation also produces phi-dependencies in the momentum pulls, not unlike what we see in real data. As a real rotation of the photon beam with respect to the z axis is unlikely, we probably observe a global rotation of the GlueX coordinate system. It was suggested to supply this rotation to the kinematic fit for real data to check if it actually cures some of the peculiar behavior.
  2. Detector related reports
    • FA125
      • Cody liaised with the TI authors to make the standalone trigger generate a trigger from the TI using the busy line. The standalone trigger is now usable.
      • For the CDC & FDC, he has a firmware version ready to test, hoping that the itrigger inconsistencies will have gone.
    • CDC
      • The EPSCI group's AIEC project is producing good results for the gain calibrations and now moving on to look at time to distance.
      • The dE/dx from the latest analysis launch looks really nice, the thumbnail histogram (click to enlarge) shows K+ dE/dx from ver 46 trees with kin fit chisq < 10 but no other cuts.
        CDC dE/dx for K+