Trout¶

Trout is the reconstruction package for the SHiP experiment. It runs on the output of the Shannon digitisation, or on real detector data. Track finding and fitting in the spectrometer use ACTS.

Repository: ShipSoft/Trout

API reference: Doxygen

How it works¶

Trout is a set of Phlex plugins configured with Jsonnet workflows (stage reconstruction). The shared configuration lives in workflows/lib/reconstruction.libsonnet:

Plugin	Role
`read_digitised_hits`	Reads Shannon's digitised hit RNTuples
`acts_geometry_provider`	Builds the ACTS tracking geometry from a GeoModel `.db` file (Geometry, Geometry Service)
`acts_field_provider`	Provides the spectrometer field map to ACTS through the Field Service
`spectrometer_tracking`	Seeds, finds and fits tracks in the straw-tube spectrometer
`upstream_tagger_reco`, `surround_tagger_reco`, `calorimeter_reco`, `timing_detector_reco`	Per-detector reconstruction (only with `full_reco`)
`rec_output_module`	Writes each reconstructed collection to its own RNTuple, with optional validation histograms

Two workflows are provided:

workflows/run_reconstruction.jsonnet runs the full reconstruction.
workflows/tracking.jsonnet runs spectrometer tracking only (full_reco: false).

Both read ../shannon/digitised_hits_time.root and write track_fit_results.root. The geometry database defaults to ../geometry/my_ship_geometry.db; override input_file, db_file and the field map for your setup.

Building¶

git clone https://github.com/ShipSoft/Trout.git
cd Trout
pixi run build
pixi run test
pixi run smoke     # generate inputs in-tree and run workflows/smoke.jsonnet

Trout depends on data-model, Geometry, geometry_service, field_service, ACTS and ship-random, all resolved from conda-forge and prefix.dev/ship-experiment/stable. It is packaged as trout on that channel.