...
Aside: Another word that was used during the discussion, but not in Dima's talk, is "virtual segmentation". In this usage, segmentation is real if an object exists in memory the geometry system for each segment; for example there is an object in memory to represent each wafer, about 10,000 to 20,000 in the full detectorvertex+tracking detectors. This, however, is not a practical solution for representing indvidual strips and pixels as there are too many of them. Instead there are objects that can compute which pixels or strips are hit given the intersection of a track with a silicon wafer; lists of hit strips and pixels are kept. This is refered to as virtual segmentation.