DD4hep Meeting May 8th, 2025

Present:     A.Sailer, M.Frank, Peter McKneown

Apologies: A.Tolosa Delgado, T.Madlehner 

Link to minutes of previous meeting

Merged PRs

• PR1428:
•  

Closed issues and fixed problems

• ISSUE1296:
•  

Pending Problems

• ISSUE1199: Persist hepmc vertex status code into output
                        ==> Should we eliminate Geant4EventReaderHepMC
                        ==> Decision: Geant4EventReaderHepMC will be removed
• ISSUE1285:  Memory Consumption of Sensitive Detectors
                        ==> Should be handled as illustrated in PR1288. Intrinsic problem of the Geant4VolumeManager;
• ISSUE1297:  Possible to dump all available readout elements?
                        ==> Possibly a copy of unsolved ISSUE580 from Valentin about enumerating all sensitive cells.
• ISSUE1319:  Problem with regexSensitiveDetector and volume IDs
                        ==> Interesting use case for reg-ex sensitive detectors
                               having a VolumeMgr equivalent.
• ISSUE1320:  Replacing a Handle<Segmentation> which contains a MultiSegmentation with the underlying Segmentation
                         ===> Unclear what he really means.
• ISSUE1335:  Uniform random picking of points on detector surfaces for noise studies
                         This problem is linked to #1297 and #580.
• ISSUE1373:  Add GeneratorInfo to EDM4hepReader (Andre)
  PR1371:        Read edm4hep (Andre)

• PR1240:       Add multithreading support to ddsim
• PR1304:       SurfaceManager: lazily construct surface maps on demand (Leonhard Reichenbach)
• PR1314:       Cylinder segment surface (Armin Ilg)
• PR1370:       Feature celeritas integration (Sakib Rahman/EIC)
• PR1377:       Use canonical variables for the installation locations of libraries and binaries (Andriish)
       ==> Idea to have an additional DD4HEP_PLUGIN_PATH and remove dd4hep plugins fdrom the LD_LIBRARY_PATH
  
  

        New Pending PRs and ISSUEs:

• ISSUE1399:  ddsim: Vertices of tau and its decay product not matching the information in the input HEPMC file
                         ---> updated issue
                         ---> Apparently Geant4 problem. Andre has submitted a ticket.
• ISSUE1431: Unstable particle decays twice in generator and in simulation creating duplicate particles
• ISSUE1443: Make user particle handler extensible
                        ---> Maybe we should take advantage and re-collect requirements.

Round Table

Andre:       NTR
Markus:    NTR
Peter:        NTR
Thomas:   NTR

AOB

- Next meeting: Discuss actions on user particle handlers - if any.

Next meeting:   May 8th, 2025