GlueX Start Counter Meeting, July 14, 2016

GlueX Start Counter Meeting
Thursday, July 14, 2016
10:00 am EDT
CEBAF Center, Room F326/327

Agenda

1. Announcements
2. Review minutes from the last meeting
3. Calibration/Efficiency Update
4. NIM/TDR
5. Action Item Review

Communication

BlueJeans

• The BlueJeans Meeting ID is 556 286 544 .
• Connect to the Meeting

Slides

Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2016 on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2016/ .

Minutes

Present:

• FIU: Mahmoud Kamel, Werner Boeglin
• JLab: Eugene Chudakov, Mark Ito (chair), Paul Mattione, Simon Taylor
• NU: Sean Dobbs

There is a recording of this meeting on the BlueJeans site.

Review of minutes from the last meeting

We skimmed through the minutes from the meeting on June 30. We noted that we have not taken any action on monitoring the dark current of the SiPMs and that the mcsmear parameters for the start counter are still in need of review.

Update on Efficiencies

Mahmoud presented a new set of slides on efficiencies. This was a follow-on to the presentation he gave Tuesday at the Analysis Meeting. Since then he has been consulting with Paul on the interpretation of the ROOT tree produced by the start counter efficiency plugin.

Here are the titles of the slides and titles of the plots in each slide presented today:

• 1: Start Counter Efficiency [title page]
• 2: Data [run used]
• 3: Run: 10492, All Tracks
  • Phi vs TrackHitDeltaPhi
  • Sector vs TrackHitDeltaPhi
• 4: Run: 10492, SC_Eff_Phi for all tracks
  • ProjectedSCHitPhi
  • ProjectSCHitPhi_Matched
  • SC_Eff_Phi
• 5: Run: 10492, SC_Eff_Sector for all tracks
  • ProjectedSCHitSector
  • SCHitSector_Matched
  • SC_Eff
  • SCHitPhi vs SCHitZ
• 6: Run: 10492, Track direction, Z of SC track intersection and Vertex
  • TrackP3_Theta
  • Theta vs HitZ
  • Theta vs HitZ
  • Theta vs VertexZ
• 7: Run: 10492, SC_Eff_Phi for ±6 degrees Δφ Cut
  • ProjectedSCHitPhi
  • ProjectedSCHitPhi_Matched
  • SC_Eff_Phi
• 8: Run: 10492, SC_Eff_Sector for ±6 degrees Δφ Cut
  • ProjectedSCHitSector
  • SCHitSector_Matched
  • SC_Eff
  • SCHitPhi vs SCHitZ
• 9: Run: 10492, SC_Eff_Phi for ±9 degrees Δφ Cut
  • ProjectedSCHitPhi
  • ProjectedSCHitPhi_Matches
  • SC_Eff_Phi
• 10: Run: 10492, SC_Eff_Sector for ±9 degrees Δφ Cut
  • ProjectedSCHitSector
  • SCHitSector_Matched
  • SC_Eff
  • SCHitPhi vs SCHitZ
• 11: Run: 10492, SC_Eff_Phi for ±12 degrees Δφ Cut
  • ProjectedSCHitPhi
  • ProjectedSCHitPhi_Matches
  • SC_Eff_Phi
• 12: Run: 10492, SC_Eff_Sector for ±12 degrees Δφ Cut
  • ProjectedSCHitSector
  • SCHitSector_Matched
  • SC_Eff
  • SCHitPhi vs SCHitZ
• 13: Run: 10492, All Tracks, 60 bins in Phi
  • Phi vs TrackHitDeltaPhi
  • Sector vs TrackHitDeltaPhi
• 14: Run: 10492, SC_Eff_Phi for all tracks 60 bins
  • ProjectedSCHitPhi
  • ProjecteSCHitPhi_Matched
  • SC_Eff_Phi

We had a detailed discussion of the meaning of the variables and implications of the plots. The secretary will not attempt to transmit all of it. Please see the recording (linked above) if interested.

In the end, we concluded that the efficiency shown in slide 5, overall 97.4%, was a reasonable starting point for the efficiency calculation. Matching between charged tracks and start counter hits was done as in the standard reconstruction where the geometric cuts are generous. Still missing is the effect of accidental hits that may contribute to an artificial enhancement of the naively measured efficiency.

NIM/TDR

Eric has been busy with time-critical tasks in Hall C. That said, document production is on his radar.