Name: LHC Monte Carlo WG subgroup meeting – data sharing and new workflows
Start: 2025-10-02T13:00:00+02:00
End: 2025-10-02T17:00:00+02:00
Location: CERN

- 1
  
  Introduction
  
  Speaker: Enrico Bothmann (CERN)
- 2
  
  Parton-level event samples
  
  contributors:
  - Sherpa/Pepper (Enrico Bothmann/Chris Gütschow)
  - MadGraph (Olivier Mattelaer et al.)
  - other generators?
  - experiments?
  
  discussion points:
  - Shared starting point for further merging/matching, shower, hadronisation, …
  - No model parameters; PDF, scales, … etc. can be easily reweighted.
  - Open Data → pheno projects, source to fill interpolation grids, …
  - Workflow aspect: Large PL samples can be generated on HPC/GPU and then served to WLCG nodes for further processing (how?); factorising parton-level production allows for fast shower/hadronisation comparisons
  - Preference format for storage/usage: stick with plain LHE? H5? Others?
  
  Speaker: Enrico Bothmann (CERN)
- 3
  
  Particle-level event samples
  
  contributors:
  - generators?
  - experiments?
  
  discussion points
  - What is the status of such efforts?
  - Can we do more/better?
  - Are there technical stumbling blocks?
  - Is there something to be done on the generators’ side to facilitate this?
- 15:00
  
  Break
- 4
  
  Storage and distribution of Monte Carlo event samples
  
  contributors:
  - experiments?
  - Rucio?
  - Zenodo?
  
  discussion points:
  - Overview and new developments
  - Will we run into storage problems with MC samples?
  - If so, to what degree can event sharing be a remedy?
  - Is there any issue to be aware of with loading input files (via Rucio?) to WLCG nodes for further processing? (this might also be discussed in the parton-level discussion)
- 5
  
  Open Data for Monte Carlo event samples
  
  contributors:
  - CERN Open Data projects?
  - Experiments?
  
  discussion points
  - Overview and new developments
  - What is the experience so far, what is the uptake?
  - How can we ensure to maximise the usefulness?