Track Point and Energy Depositions
The track points found in the data structure, SciFiEvent->SciFiTracks->TrackPoints, are produced from Kalman for the tracker planes they originated in. The values of momentum/energy are deduced after the interactions within that plane.
This means our reconstruction is slightly non-symmetric. Upstream is fine, downstream we technically record points AFTER the first tracker plane, rather than before - as required for symmetry about the absorber. For an ideal emittance reconstruction we need the values extrapolated to before the plane interactions.
Updated by Santos, Edward about 8 years ago
Spoke with Chris. From the track fit point of view, the trackers are treated symmetrically. Chris, on the other hand, is thinking from the point of view of the MC steps. The differences we are discussing can't be fixed and they don't dominate the error we make when estimating the absolute momentum of the muons. Chris might want to add the effect this has on the emittance and its correction (the effect is only visible at the 4th decimal digit of the emittance value, right?).
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