ACTS and JANA2 based package for TDIS multi-TPC chamber tracking reconstruction.

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To run 100 events and plot fit efficiency plus momentum, angle and radial DCA resolution, see the tracking performance workflow.

ROOT output and schema 102

A schema defines the saved objects, fields, units and relationships in a reconstruction file. 102 is the current TDIS data-model version, declared in source/tdis/edm.yaml.

Schema 102 distinguishes a fitted beamline perigee (FittedTracks.type = 0) from a cylinder fallback when inward extrapolation fails (type = 1). FittedTrackParameters uses the same reference types; perigee surface ID 0 means closest approach to the z-axis through the origin, not a vertex constrained to (0,0,0). Lengths are stored in mm, angles in radians and times in ns. Version 101 established the cylinder-local hit covariance convention; 102 adds these reference/status conventions without changing the field layout.

For collection definitions, units and compatibility details, see the schema reference. Run settings such as Bz and the chi2 cut are separate and recorded in run.json.

Reconstruction χ² cut

The KF rejects a selected measurement when its pre-update innovation χ² exceeds 25 by default. This is a per-measurement cut using the predicted and measurement covariances, separate from total track χ². Inside the TDIS image:

bash tdis/scripts/run_tracking_performance.sh INPUT.txt --chi2-cut 25 --analyze

Use --chi2-cut VALUE to change the limit, or --chi2-cut 0 to disable it. Direct TDIS runs use -pKalmanFittingFactory:chi2_cut=VALUE, also defaulting to 25. Rebuild/install the current code to pick up the new fitter default. The runner records the effective setting in run.json; see script examples.

Plot a fitted event

Inside the TDIS image:

python3 tdis/scripts/plot_event_display.py PATH/TO/reco.tdisedm.root \
  --event 7 -o tdis/tmp/event-7-display

Replace the ROOT path and choose a new output directory. --event selects the processed JANA event ID. The directory contains an overview and one populated plane per PDF page, matching PNGs and display.json; this script only generates the event display. Signed Bz comes from the sibling run.json, or an explicit --bz value. See script examples for the full performance report and independent raw-hit plotting commands.