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add ActsTrkFinding to use ACTS CKF

Tim Adye requested to merge adye/athena:23.0.9-adye into master

A first implementation of ActsTrkFinding/TrackFindingAlg and ActsTrkFindingTool/TrackFindingTool to use Acts::CombinatorialKalmanFilter from Athena.

  • With --preInclude ActsInterop.ActsCIFlags.actsValidateTracksFlags:
    • replaces Athena track finding with Acts track finding. Subsequent steps use Acts Trk::Track outputs, so default IDPVM can be used for performance studies.
      • It looks good so far, with one big exception: a large loss of efficiency in the barrel, probably due to loss of most strip hits.
    • also replaces the Acts clusterization with the Athena clusterization in the Acts workflow. This is needed to create PRD links, which are needed while we use Trk::Track as output of the track finding.
  • To-do following this MR:
    • fix strip hit association
    • revisit tool interface, or move tool functionality into algorithm.
    • improve Trk::Track creation or replace with new Acts::Track. For Trk::Track:
      • does not add outliers from reverse filtering - is this needed?
      • uses legacy Athena enums, Trk::TrackInfo::TrackFitter::KalmanFitter and Trk::TrackInfo::TrackPatternRecoInfo::SiSPSeededFinder
      • only works with Athena clusterization
      • Unlike Athena algorithm, no additional fit required after Acts CKF. We should disable the global Chi^2 fit in the ambiguity solver.
      • are we using the correct TSOS to calculate the track parameters?

Implements ATLIDTRKCP-355. Details and performance discussed here.

Edited by Tim Adye

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