BCAL Readout Segmentation Task group Meeting: Nov. 7, 2011

Meeting Info

Time:

• 1:30 JLab
• 12:30 Regina

Location:

• CC F326

Vid-con:

• ESNet 8542553
• EVO

• Phone connection:
  • +1-866-740-1260 : US+Canada
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  • then enter participant code: 3421244# (remember the "#").
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Agenda

Review action items from previous meeting

1. TBD

New Agenda items

1. π^o mass width (David)
2. BCAL Charged PID Update (Paul)
3. Status of Document (Zisis)
4. Discussion on argument sharpening (All)
   1. Timing resolution (quantitative)
   2. Neutron-photon separation (quantitative)
   3. proton-pion ID (quantitative?)
   4. analysis/PWA (likelihood, qualitative?)
   5. Energy resolution and Invariant masses (not very sensitive, qualitative?)
   6. FOM

Minutes

Participants

Curtis M., Paul M., Eugene C., Elton S., David L., Andrei S., George L., Beni Z.,

π^o mass width

David showed some slides summarizing a parametric M.C. study he did to calculate the π^o mass width for b₁π events. Details on the input resolutions used were given. The results were shown in the form of the mass width as a function of a scaling parameter for each of the input uncertainties. These indicated that the energy resolutions were the dominant contributor to the width. Some discussion was had:

• Andrei noted that the segmentation scheme can contribute to the energy resolution indirectly through cluster separation
• Andrei also noted that in the spring, early M.C. studies indicated a better energy resolution for the FINE segmentation scheme compared to the 334 at low energies
  • Dave noted that this was done using the KLOE code which was not optimized for any particular scheme so there was some doubt clouding those results.
• It was noted that the sampling fluctuations were never handled completely correctly in Dave's simulation so the energy resolution may be different for the schemes under consideration.

BCAL Charged PID Update

Paul showed some plots of his π(1600) -> b₁π M.C. Study.

• Some profiles indicating the π proton separation at specific momenta for the 334 scheme
  • Similar plots which will include the 1234 scheme will be produced in the near future
• A plot of the residual time relative to the true time was shown and was asymmetric. It was not immediately clear why the asymmetry was there
• Time resolutions imposed on the data were done to reconstructed values instead of truth values. Paul was going to modify his simulation to use smeared truth values.

Status of Document

A discussion was had on the document Zisis circulated an alpha draft of.

• Elton asked about the neutron rejection plots Andrei supplied and if the information content could be displayed in a way that made it easy to compare the two schemes for a fixed photon reconstruction efficiency. Andrei will work on that
• It was suggested one or two of Beni's plots be added to the document.
• Paul will produce a plot comparing 334 to 1234 π/proton separation
• There was some discussion of the deadline for presenting the case. The middle of Nov. is still considered a solid deadline. We will work to refine the existing document over the next week in order to have a draft to show to Glenn next week.
  • Zisis was out sick today so the hope is that he will get better quickly and if not, send us the source so that the document can be further developed in his absence.

Discussion on argument sharpening

There was no additional discussion beyond the previous topic.

Action Items

1. Identify plot(s) on neutron/photon discrimination that could be used in document (Beni)
2. Re-format information in efficiency plots to view easily at fixed photon efficiency (Andrei)
3. Add 1234 scheme to plots showing π/proton separation and use smeared truth values for timing (Paul)
4. Continue refining document so full draft available by next week (Nov. 14) (Zisis)