[Aki: Re-surveying INTT]
- Joseph will summarize the recent calibration of INTT geometry.
- The stress, which was applied when the barrel was installed to sPHENIX, could change the barrel-to-barrel geometry. That kind of misalignment cannot be measured by re-surveying anyway.
- Itaru will talk to Dan Cacace about his thoughts on the re-surveying.
- Basically offline alignment with track will do better calibration than doing re-surveying.
- The only room for the survey results can be better than the alignment with tracks is the physical position of the ladders in radial direction. The ladder position in radial direction is insensitive for tracks. If we have any suspicious data which indicates relatively poor or too much overlapping hits between adjacent ladders, that can be the evidence of poor alignment of ladders in radial direction. Then it may be worthy to arrange ladder-by-ladder survey.
- If some systematic misalignment can be observed in the calibration, we can double check with the global position re-surveying.
-- Summarize such information in the wiki before that happens.
- If barrel-to-barrel survey could be possible after the INTT is taken from IR, it would be nice to check the position of one particular ladder which shows a large misalignment in the calibration.
- Cheng-Wei will send the calibration file (and plot) to show the difference from the original survey data.
- We already have enough zero-field run for Au+Au.
-- Need additional zero-field run for p+p?
[INTT group's thoughts on re-surveying]
- At this moment, we don't need any additional re-surveying for INTT for global or ladder-by-ladder.
-- The offline calibration will work better than the re-surveying.
-- Itaru will talk to Dan Cacace about the re-surveying.
- We won't object to any re-surveying if sPHENIX group decide to do and have manpower for it.
