Context/Requirements
- TOF DSC has developed a charge sharing algorithm they would like to integrate into the digitization/reconstruction chain (while returning the TOF sensors to physical sizes)
- Algorithm operates on SimTrackerHits and is currently placed ahead of PulseGeneration, which accepts SimTrackerHits.
- This requires output to also be SimTrackerHits. However, need a way to go from charged-shared sim hits to non-charged-shared sim hits.
- Hence, the introduction of SimTrackerHitLinks
- TOF DSC would like to ensure that this algorithm can be easily removed from chain
Key points from discussion (so far)
- Link name has been changed SimTrackerHitLink (as discussed in S&C meeting)
- Sticking points from S&C discussion:
- Link will make forming MC-track associations tricky (now have 2 steps to get back to MC particle)
- Not clear how well this generalizes to other subsystems which will need charge sharing
- Options considered for addressing one-step MC-track associations
- Make charge-shared rec hits from non-charge-shared raw hits
- Parallels approach w/ SVT noise-injection
- But would require change later when developing digitization algorithms
- And raw hits are supposed to be already digitized quantities
- Have algorithm output raw hits (or a new hit type)
- But then have to modify pulse generation to accept raw/new hits in addition to sim hits
- OR update all algorithms piping into pulse generation to output to raw/new hits
- Addressing point on generalization:
- Likely requires new type for charge sharing (or adding a hit-to-hit relation to sim hit)
- But then need to modify all downstream algorithms to account for this new type in the chain
Thoughts
- From Dima: introduce algorithm + dummy algorithms for other trackers
- From Simon: keep type as-is and introduce it, and start working towards new hit
