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- There are two tagging options: conservative (if both xtal ends are ghost-like) and permissive (if at least one xtal end is ghost-like).
- I used permissive since purity is high and efficiency is looks low (see below).
- The energy threshold for tagging a xtal end is set to 120 MeV (no good reason for this number, need to be optimized).
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- Johan algorithm works fine!
- Clusters with at least one ghost-tagged xtal tend to have large overlay energy.
- Only in one case the overlay energy is 0 and there is some ghost-tagged xtal (mostly connected to the energy threshold). The 'purity' of such selection is ~1.
- Efficiency is low. We can't tag a good fraction of ghost clusters in this way. (this was my impression before looking at periodic. In AG there is no energy selection)
- There are few events with low overlay energy and low ghost-tagged energy. After looking at event displays I think we can consider good cluster is the ghost-tagged energy is <~3%
- My suggestion for ghost tagging ghost clusters is "TagGhostNumXtals>0 && (TagGhostRawEnergySum/CalRawEnergySum)> 0.03"
- This is valid for permissive E >= 105 MeV.
- We can include this algorithm just after clustering, and then tag ghost clusters. Not sure how we should use this info:
- Select best cluster only if non ghost-tagged - what happen if the best cluster is also a ghost (i.e. there are no other options?)?
- Use this info in tracking ( e.g. knowing that the direction is likely to be wrong). Need Tracy here...
- Use in event-level analysis to select events with useless cal information (and treat them as tracker only if possible)
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