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Meeting Main Page- Meeting Agenda - All Meetings Reports - BT F2F in Washington - BT EVO Meetings
Template
first attempt: DRAFT
- Instrument performances and features
- what we understand and what we do not
- e.g.: PSF, energy resolution, absolute energy scale, CAL xtalk, Tkr alignment...
- MC simulation
- what we understand and what we do not
- e.g.: beam line, physics list
- Angular resolution (Understood)
- Hadronic physics (Understood)
- Absolute energy scale (Not Understood)
- MC EM Shower profile (Not Understood)
- Potential impact of CU beamtest systematics upon LAT astrophysical measurements
- How we plan to study this issue
Comment(Elliott): In your talk I generally agree with the points. However, as I mentioned in the meeting on Wednesday, Nov7, the anti-quenching seen for heavy ions in the two GSI beam tests is still a mystery. Also, the comparisons that Ping has been making between dE/dx theory and GEANT (GLEAM) for the mean energy loss (using MC truth) show a sensitivity to the cuts on the muons. There is good agreement for muons between dE/dx theory and GLEAM for the mean energy deposit, but only for no cuts. Just making a mild directional cut on the muon in the CALdirZ paramenter gives a few percent antiquenching like effect of GLEAM MC vs theory. Preliminary results on protons and C using MC (Ping) and data (Yvonne) also show a strong dependence in the mean energy loss on cuts (in this case energy deposit, not loss). These effects seem to be angle dependent. Thus, I believe that we have a lot of work yet to understand these effects that are the basis of our energy calibration method on orbit. I would feel that we are taking a large risk in using the GSI antiquenching results at face value in our calibration proceedures.
List of all analysis topics
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