Juraj Smieško (CERN)

8th FCC Physics Workshop

CERN

13–16 January 2025

FCCAnalyses Overview

Analysis framework inside Key4hep ecosystem build
on top of the ROOT RDataFrame

• Manages input samples
  • Remote pickup of required information
• Has standard library of functions
  • Many C++ HEP frameworks available
• Runs the dataframe
  • Local or remote execution
• Helps with histograms/plots
  • Export of results to other tools
• Registry for the analyses
  • Dedicated place for all case-studies

Key4hep

Coherent set of packages, tools, and standards for different collider Concepts

• Common effort from FCC, CLIC/ILC, EIC, CEPC, Muon Collider, …
  • Preserves and adds onto existing functionality from iLCSoft, FCCSW, CEPCSW, …
  • Builds on top of the experience from LHC experiments and results of targeted R&D (AIDA, …)
  • Many institutes involved: CERN, DESY, IHEP, INFN, IJCLab, …
• Each project rebases its stack on top of Key4hep
• Having common building blocks enables synergies across collider communities
• Main ingredients:
  
  • Event data model: EDM4hep, based on PODIO, AIDA project
  • Event processing framework: Gaudi, used in LHCb, ATLAS, …
  • Detector description: DD4hep, AIDA project
  • System to build, test and deploy: Spack, suggested by HSF + CVMFS

EDM4hep

Common language for processing and persistifying data

Versions of FCCAnalyses

Or how to get and run FCCAnalyses

• Latest version of FCCAnalyses can be obtained from:
  • GitHub:
    git clone git@github.com:HEP-FCC/FCCAnalyses.git
  • Key4hep nightlies stack:
    source /cvmfs/sw-nightlies.hsf.org/key4hep/setup.sh
• Latest released version of FCCAnalyses is v0.10.0 and can be obtained from:
  • GitHub:
    git clone --branch v0.10.0 git@github.com:HEP-FCC/FCCAnalyses.git
  • Key4hep release stack:
    source /cvmfs/sw.hsf.org/key4hep/setup.sh
• Specialized version for winter2023 samples can be obtained only from:
  • GitHub:
    git clone --branch pre-edm4hep1 git@github.com:HEP-FCC/FCCAnalyses.git
• Recommendation:
  FCCAnalyses can be run without compiling — fccanalysis command is part of the Key4hep stack

Centrally produced samples

Management of centrally produced samples

• Samples include generator level files, parametrized simulation and Fullsim samples for FCC-ee and FCC-hh
• Samples stored on EOS at:
  /eos/experiment/fcc/<accelerator-type>/generation/
/eos/experiment/fcc/prod/fcc/<accelerator-type>/
  • Ongoing transition from EventProducer to iLCDirac (FCC configurations)
• Detailed information about the samples published on FCC Physics Events website
• FCCAnalyses framework automatically picks up the sample information from YAML and JSON files
  The interface under overhaul, to allow the information to be consumed also by other analysis solutions
• Old samples moved to tape (FCC-hh v02, v03, v04)
  • Sample list will be kept on the website

EOS Analysis Space

Various intermediate files of common interest can be stored centrally

Standard library of analyzers

Set of self-contained functions/functors operating on ROOT dataframe

Towards better defined analysis script

Analysis encapsulated into a class

Analysis CLI arguments

Analysis script can use parameters provided from the command-line.

Submit sub-command

Extracting submission machinery from analysis execution

• Done in order to allow for other forms of distributed computing other than HTCondor
• Improves also current HTCondor submission machinery
• Will allow running of Histmaker style analyses on HTCondor
• Usage: fccanalysis submit ana_script.py
• Almost ready to be merged: PR#422

PODIO Datasource

Preserving EDM4hep relationships in RDataFrame

• Collection objects in PODIO/EDM4hep can be accessed on several layers
• Highest layer provides one-to-many and many-to-many relationships
• Easy access to the related objects greatly improves writing and understanding of the analyzer
• Price for this convenience is performance
  Alternative: NTuple creation in Gaudi algorithm

Enabling PODIO Datasource in the analysis:

• Use analyzers which take as input EDM4hep collections:
  edm4hep::ReconstructedParticleCollection, edm4hep::RecoMCParticleLinkCollection, ...
• Instruct FCCAnalyses to use podio::DataSource:
  self.use_data_source = True or fccanalysis run --use-data-source ana_script.py

Recent improvements

Improvements from users are highly welcome!

• Variable event weights implemented in the context of FCC-hh
• TMVAHelper: support for BDT/MVA using XGBoost
• Export of Combine datacards from the Final stage/Histmaker outputs
• Harmonization of (meta)data exchange between individual stages
  • Includes exports of cut-flows in TeX and JSON format
• Plotting improvements
• Logging / print-out support for C++ analyzers
• Running in SWAN

Analysis registry

Central registry for the FCC case studies

• Two repositories:
  • FCCeePhysicsPerformance lists FCC-ee case studies
  • FCChhPhysicsPerformance contains FCC-hh physics performance documentation
• Experimentally one can create analysis package for analysis specific code
• Rudimentary and in need of overhaul
  • Based on the post FSR needs

Tests and benchmarks

Ensuring correctness and performance

• Tests of the FCCAnalyses framework are done daily
  • Test suite is published in FCCTests
  • Goal is to ensure FCCAnalyses be available in the Key4hep nightlies stack
  • Every test run inside independent subprocesses
  • Tests need access to LXPlus like environment
    • Missing HTCondor testing
• Benchmarks of FCCAnalyses is done after every merge of a PR
  • Benchmarks run on small set of events
  • There is no guaranteed machine to run on
  • Benchmarks of Higgs mass recoil example on LXPlus:
    20k–45k evt/s

All the Links

Broader Plans

• Focus on distributed computing
  • Allow running on GRID, Slurm or other platforms
• Make FCCAnalyses able to run on non LXPlus machines
• Improvement to sample management
  • Make it consumable by other analysis solutions
• Better ML support
  Depending not only on the ROOT capabilities
• Expand plotting facilities
  • Many products in the Python HEP space
  • Integrate existing tools or make FCCAnalyses more interoperable
• Improve performance of EDM4hep relationship handling
• Streamline NTuple production mechanism

Conclusions