Data

Location

The meson structure data is available from the following locations:

LATEST PROCESSED FILES
(last update of May 2026 — campaign 2026-05)

Campaign 2026-05 is the first full production run after the #1069 / #1081 fixes were folded in. It includes both the regular dd4hep flavor (fixed tracking volume) and a dd4hep_saveall flavor that keeps all MCParticles. EICrecon reconstruction is run on top of the saveall flavor.

There is an important distinction. Issue #1069 showed that even with the tracking volume not all MCParticle daughters are saved even if they reach calorimeter sensitives. The _saveall flavor keeps all MCParticles and their connections to hits.

(!!!) ALL ACCEPTANCE STUDIES MUST BE DONE USING "_saveall" DATA.

Reconstruction-based analyses can use reco / csv_reco directly.

On JLab ifarm:

/work/eic3/users/romanov/meson-structure-2026-05

On XRootD (open for universities and public)

xrdfs root://dtn-eic.jlab.org
ls /work/eic3/users/romanov/meson-structure-2026-05

Subdirectories

• afterburner - eg + beam effects
• dd4hep - EDM4Hep simulated data, fixed tracking volume (#1069)
• dd4hep_saveall - EDM4Hep simulated data, all MCParticles saved (acceptance studies)
• reco - EICrecon reconstructed data (built on dd4hep_saveall)
• csv_dd4hep - CSVs from dd4hep (acceptance, fixed volume)
• csv_dd4hep_saveall - CSVs from dd4hep_saveall (acceptance, all particles)
• csv_reco - reconstruction-based CSVs

Previous: 2026-04 investigation

The 2026-04 dataset is a small investigation sample tied to issues #1069 / #1081 — DD4hep + afterburner only, no reconstruction. See campaign 2026-04.

/work/eic3/users/romanov/meson-structure-2026-04-check

Older (and not valid in terms of issue #1069 data:)

On JLab ifarm:

/volatile/eic/romanov/meson-structure-2026-03/reco

# CSV files 
/volatile/eic/romanov/meson-structure-2026-03/csv_eicrecon

# priority queues (first 1'000'000 events == 200 files from each energy range):
/volatile/eic/romanov/meson-structure-2026-03/reco/5x41-priority
/volatile/eic/romanov/meson-structure-2026-03/reco/10x100-priority
/volatile/eic/romanov/meson-structure-2026-03/reco/10x130-priority
/volatile/eic/romanov/meson-structure-2026-03/reco/18x275-priority

#CSV files are located in csv_eicrecon and csv_dd4hep folders now: 
/volatile/eic/romanov/meson-structure-2026-03/csv_eicrecon/5x41-priority
/volatile/eic/romanov/meson-structure-2026-03/csv_eicrecon/10x100-priority
/volatile/eic/romanov/meson-structure-2026-03/csv_eicrecon/10x130-priority
/volatile/eic/romanov/meson-structure-2026-03/csv_eicrecon/18x275-priority

On XRootD (open for universities and public)

xrdfs root://dtn-eic.jlab.org
ls /volatile/eic/romanov/meson-structure-2026-03/reco

In this campaign we put processing files in separate folders:

• eg-orig-kaon-lambda - original event generator files, 10mil events in each energy range
• eg-hepmc - event generator files split by 5k events and converted to HepMC
• afterburner - generator files with applied crossing angle and beam effects
• dd4hep - DD4Hep full simulation result (edm4hep.root files)
• reco - EICrecon reconstruction results (edm4eic.root files)
• csv - CSV files from reconstructed results

The campaign is made with eic-shell v26.03.0 container

Writing libraries versions (important for C++ readout compatibility):

• podio: v01-03
• edm4hep: v00-99-01
• edm4eic: v8.0.1
• cxxstd: 20

Original MCEG files on ifarm: /volatile/eic/romanov/meson-structure-2026-03/eg-orig-kaon-lambda
(last update of August 2025)

File names:

File names are:

# The pattern:
k_lambda_{beam}_5000evt_{idx}.{ext}

# e.g.
k_lambda_10x100_5000evt_045.edm4eic.root

Where:

• {beam} Beam energy configuration [5x41, 10x100, 18x275]
• {idx} - zero padded index [001-200]
• {ext}
  • *.info.yaml - Input and processing metadata
  • *.afterburner.hepmc - Beam effects afterburner output
  • *.afterburner.hist.root - Afterburner before-after histograms
  • *.edm4hep.root - DD4Hep (Genat4) output
  • *.edm4eic.root - EICRecon reconstructed files
  • *.mcdis.csv - MC DIS CSV table
  • *.mcpart_lambda.csv - MCParticles based CSV table full lambda decay values

5000evt indicate each file has 5k events

Accessing Data with XRootD

The data is available remoutly through XRootD via:

root://dtn-eic.jlab.org

To browse the available files one can use xrdfs command:

xrdfs root://dtn-eic.jlab.org
ls /volatile/eic/romanov/meson-structure-2026-03/reco

To download files:

xrdcp root://dtn-eic.jlab.org//volatile/eic/romanov/meson-structure-2026-03/reco/5x41-priority/k_lambda_5x41_5000evt_001.edm4eic.root ./

To use directly in scripts:

# Both uproot and pyroot can work with links directly 
# if XRootD is installed in the system
import uproot
file = uproot.open("root://dtn-eic.jlab.org//volatile/eic/romanov/meson-structure-2026-03/reco/5x41-priority/k_lambda_5x41_5000evt_001.edm4eic.root")