bremsstrahlung-track matching with selective search in calo
Adds an algorithm, SelectiveBremMatchAlg, that bases its track calo-object matching on finding the cell IDs related to the extrapolated track states before the magnet for bremsstrahlung recovery. Can add squares of neighbours around these cells to reduce the number of calo-objects one is trying to match to. Based on Rec!2216. It aims to replace BremMatchAlgFuture
and its underlying algorithms.
Output of SelectiveBremMatchAlg:
- Matching chi2 of cluster with track under bremsstrahlung hypothesis
- Energy of cells identified by track extrapolation (more selective than 3x3 cluster(ization))
- Test statistic of whether matched cluster is 'first-state like' versus 'last-state-before-magnet like', which gives an indication of where the bremsstrahlung comes from (real brem favours first state, fake brem is random)
In addition, this MR updates the brem acceptance to use the first state and not the last state before the magnet.
A combination of the energy of the cluster and the selective energy determination can be used to optimize bremsstrahlung momentum recovery.
More info in link-to-pdf
Implementation in Moore here: Moore!707 (merged)