(WIP) Software

Last update: 22 Mar 2022 [History] [Edit]

warning The construction of the page is still in progress.

These pages explain the internal structure of the flavour tagging software in Athena release 22.

Useful References

The (ATLAS internal) TWiki page of the software group can be found here.

  • explanation of StoreGate on the twiki [ATLAS members only]
  • explanation of event data access in AthenaMT on the twiki [ATLAS members only]
  • another twiki on BTaggingAthenaMT [ATLAS members only]

Overall Structure

This diagram shows the overall structure of the algorithms involved in flavour tagging and their access to StoreGate. Links to the code of the different algorithms in gitlab are given below in the next section describing each algorithm separately.

This is the main diagram showing the structure of the software. It is designed to be used also in public talks.

This second diagram is a bit older (the algorithms for the high-level taggers were still in migration), but has some more technical details that might be interesting.

Diagrams of the Existing Algorithms

These are specific diagrams of the algorithms mentioned in the above overview diagrams. These diagrams were created in Spring 2020. Since the code migration to the new release was still in progress at that moment, some parts of the structure were not yet determined.

JetParticleAssociationAlg

This algorithm does the track - jet association.

header in gitlab, .cxx file in gitlab

JetSecVtxFindingAlg

This algorithm creates the secondary vertexing info container used in the JetSecVertexingAlg and the BTagLightSecVertexing tool of the JetBTaggingAlg. Making this info container was put into its own algorithm since it is used in both in the JetSecVertexingAlg and the BTagLightSecVertexing tool and quite CPU consuming.

header in gitlab, .cxx file in gitlab

JetSecVertexingAlg

This algorithm does the secondary vertexing.

header in gitlab, .cxx file in gitlab

JetBTaggingAlg

This is the new main algorithm.

header in gitlab, .cxx file in gitlab

BTagTrackAugmenterAlg

This algorithm does some more preparation on the tracks before the RNN algorithm is run.

header in gitlab, .cxx file in gitlab

Still in migration to the new release while the diagrams were created:

  • the BTagNNAlg doing the RNN
  • the algorithm doing the DL1