ACD recon information as visualized in Fred
Hits and Digis
Every hit tile and ribbon is represented by highlighting the outline of the tile or ribbon as seen by the AcdGeometrySvc. For ribbons this is slightly simplified relative to the GEANT model as small segements are excluded. The advantage of this is that it can be used to debug the reconstruction by show the geometry exactly as it is seem by the reconstruction algorithms.
Here are some examples:
This one shows a hit Tile (204) with a veto fired (red) and a hit Ribbon (503) without a veto (violet).
Track extrapolations and ACD associations (AcdTkrAssoc)
This show how the ACD reconstruction data is associated with a track (in yellow). The extrapolation is show in dark yellow. The outline of the hit tile appears in red. The circle with error bars show the projection of the track to the plane of the hit tile.
Associations with Hit Tiles (AcdTkrHitPoca with signals)
This is a blow up of the previous plot, showing some more details.
The red circle is the intersection point with the tile plane. The distance from that point to the tile edge is the 2D active distance.
The light violet error bars are from projecting the error at the head of the track, the darker error bars are from the full Kalman propagation to the intersection point.
The green line connecting the track to the tile edge is the vector from the point of closest approach along the track to the tile edge. The length of the vector is the 3D active distance. In this particular case that is also the distance to the closest gap.
Associations with Gaps (AcdTkrGapPoca)
In this case the track points to a tile that doesn't have a signal. We don't see the red lines associated with the best hit association, but we do see the green lines associated with the gap caculcations.
