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  1. meeting link to zoomgov
  2. meeting page

Thu 2/23/2023 2pm


  1. Detector status:
    • CDC
    • FDC
    • GEM-TRD
  2. Tracking
    • Differences between run periods
      • Ratios of {\frac  {d\sigma }{dM}} for pK^{{-}}K^{{+}} production for the different beam times and batches. Ratios are always taken with respect to full 2018-08 data.File:L1520 cs ratios.pdf
      • Same ratios vs beam current * radiator thickness
        xs/xs(fall 2018) vs
      • Alex's rho xs update, dependence on beam current in 2017 SDMEs
        Rho SDME 2017-01 beam current.png
      • Thoughts:
        1. Run monitoring histograms (CDC_Efficiency, CDC_dedx what else?) over bggen
        2. Are the random triggers enough to simulate the extra DC hits (from photons) in 2017 before the W foil was added? We might be able to identify these from integral/amplitude.
        3. For the higher intensity runs we might be able to use the quality codes from the timing algo, it identifies pulses w too high pedestal.
        4. What is already in the MC, that we aren't using properly? Pedestal width? Straw efficiency?
  3. AOB


  1. Detector status:
    • CDC - ok
    • FDC - non-critical problem that Lubomir is aware of, he will be back in a few days
  2. Tracking
    • We looked at the plots from Peter and Alex and shared ideas. The std dev on each of Peter's ratio plots is about 5%, so the spread in the fall 2018 results is reasonable, and the earlier batches from spring 18 are similar. We need to look more at the low and high intensity data from spring 17 which differ by ~ 20% in Peter's data and also show differences in Alex's rho SDMEs, the unpolarized SDMEs are likely them most sensitive to the absolute normalization. The W foil was added to the beamline between the spring and fall 18 runs, so the extra hits from photons before that probably aren't the culprit.
    • Things we can do:
    1. The spring 17 data had a different reconstruction version. Peter will recheck low and high intensity spring 17 data using the REST 4 data.
    2. The CDC straw efficiency is modelled as 1/0, but could use floats. Naomi will make a CCDB variation with per straw efficiencies from s17 as floats, share w Peter & Alex.
    3. Naomi will compare overall hit efficiency vs DOCA and pedestal widths from high & low intensity runs in spring 17.
    4. Naomi: find phi xsections for diff run periods
    5. Monitoring launch over bggen for different run periods might reveal something useful. Last did this a long time ago. Worth revisiting w new samples. Alex will do this.
    6. Maybe the CDC HVB currents can tell us something useful about the background hits.
    7. Sean: tag and probe eff study for delta ++ would be helpful. Jon might have a MC config file.
    8. 2017 trees with looser PID timing cuts could be useful - need a new analysis launch (start w high intensity 17)
    9. Naomi: We need to look at the QF codes from the timing algo for the recent very high intensity runs, we might be able to do some bad-hit recovery.
PB monitoring histos, there's a tiny drop visible in the later (higher intensity) run. Also see these plots of efficiency vs run.