Output Reference
The output ROOT file contains a single tree named Parnassus. Branches use flat dot-separated names; access them in uproot as tree["Collection.Field"].array().
For each jagged collection, uproot also writes a count branch (nTruth, nPFlow, nTruthJetsAntiKt05, etc.). These are internal bookkeeping branches and do not need to be read directly.
Particle Class IDs
The ClassID field maps to particle type:
| ClassID | PDG ID | Particle |
|---|---|---|
| 0 | 211 | Charged hadron (\(\pi^\pm\)) |
| 1 | 11 | Electron |
| 2 | 13 | Muon |
| 3 | 111 / 130 | Neutral hadron (\(\pi^0\) in neural; \(K_L^0\) or original PID in parametric) |
| 4 | 22 | Photon |
Neural mode
Truth
| Branch | Description |
|---|---|
Truth.PT |
Transverse momentum (GeV) |
Truth.Eta |
Pseudorapidity |
Truth.Phi |
Azimuthal angle (rad) |
Truth.X, Truth.Y, Truth.Z |
Production vertex (mm) |
Truth.ClassID |
Particle class (see table above) |
Truth.PID |
PDG ID |
Truth.<JetName>_idx |
Index of associated jet, present for each configured clustering pipeline with collection: truth (e.g. Truth.TruthJetsAntiKt05_idx) |
PFlow
| Branch | Description |
|---|---|
PFlow.PT |
Transverse momentum (GeV) |
PFlow.Eta |
Pseudorapidity |
PFlow.Phi |
Azimuthal angle (rad) |
PFlow.X, PFlow.Y, PFlow.Z |
Production vertex (mm) |
PFlow.ClassID |
Particle class |
PFlow.PID |
PDG ID |
PFlow.D0 |
Transverse impact parameter (mm) |
PFlow.Z0 |
Longitudinal impact parameter (mm) |
PFlow.ErrorD0 |
Uncertainty on D0 (mm) |
PFlow.ErrorZ0 |
Uncertainty on Z0 (mm) |
PFlow.<JetName>_idx |
Index of associated jet, present for each configured clustering pipeline with collection: pflow |
Parametric mode
Truth
| Branch | Description |
|---|---|
Truth.P |
Total momentum (GeV) |
Truth.PT |
Transverse momentum (GeV) |
Truth.Eta |
Pseudorapidity |
Truth.Phi |
Azimuthal angle (rad) |
Truth.Mass |
Particle mass (GeV) |
Truth.X, Truth.Y, Truth.Z |
Production vertex (mm) |
Truth.T |
Time of flight (s) |
Truth.PID |
PDG ID |
Truth.ClassID |
Particle class |
Truth.Charge |
Electric charge |
Truth.Status |
HepMC status code |
Truth.<JetName>_idx |
Index of associated jet, present for each configured clustering pipeline with collection: truth |
PFlow
Same fields as Truth (P, PT, Eta, Phi, Mass, X, Y, Z, T, PID, ClassID, Charge, Status) plus PFlow.<JetName>_idx for each configured clustering pipeline with collection: pflow. No impact parameters.
Track
Reconstructed charged particle tracks after efficiency and smearing. Same fields as parametric Truth (P, PT, Eta, Phi, Mass, X, Y, Z, T, PID, ClassID, Charge, Status), accessed as Track.*. No jet indices.
Tower
Calorimeter tower deposits.
| Branch | Description |
|---|---|
Tower.E |
Energy (GeV) |
Tower.ET |
Transverse energy \(E / \cosh(\eta)\) (GeV) |
Tower.Eta |
Tower centre \(\eta\) |
Tower.Phi |
Tower centre \(\phi\) (rad) |
Tower.T |
Tower time (s) |
Parametric debug collections
When generator.debug: true, parametric mode also writes intermediate detector-stage collections. Particle-like debug collections use the same fields as parametric Truth (P, PT, Eta, Phi, Mass, X, Y, Z, T, PID, ClassID, Charge, Status). Tower-like debug collections use the same fields as Tower (E, ET, Eta, Phi, T).
| Collection | Field set | Description |
|---|---|---|
ParticleBeforeProp |
particle-like | Stable particles before detector propagation |
ParticleAfterProp |
particle-like | Particles after detector propagation |
ChargedHadron, Electron, Muon, NeutralParticle |
particle-like | Particle categories split before efficiency and smearing stages |
ChargedHadronEfficiency, ElectronEfficiency, MuonEfficiency |
particle-like | Particles surviving tracking efficiency |
ChargedHadronSmeared, ElectronSmeared, MuonSmeared |
particle-like | Particles after momentum smearing |
ECal_EFlowTrack, EFlowTrack |
particle-like | Track-like energy-flow intermediates |
ECalTower, HCalTower, EFlowPhoton, EFlowNeutralHadron |
tower-like | Calorimeter and neutral energy-flow intermediates |
Lepton collections (both modes)
Electrons and Muons are always present in both neural and parametric output. They are extracted from PFlow and use the same branch names, replacing <Lepton> with either Electrons or Muons.
Kinematics
| Branch | Description |
|---|---|
<Lepton>.PT |
Lepton transverse momentum (GeV) |
<Lepton>.Eta |
Pseudorapidity |
<Lepton>.Phi |
Azimuthal angle (rad) |
Impact parameters
These fields are present only in neural mode when the impact model ran. Parametric mode does not include impact parameters.
| Branch | Description |
|---|---|
<Lepton>.D0, <Lepton>.Z0 |
Impact parameters (mm) |
<Lepton>.ErrorD0, <Lepton>.ErrorZ0 |
Impact parameter uncertainties (mm) |
Isolation fields
These fields are present when an isolation pipeline is configured for the lepton collection.
| Branch | Description |
|---|---|
<Lepton>.IsolationVar |
Relative isolation: (\(\sum p_T\) in cone) / \(p_T\) |
<Lepton>.SumPt |
Total \(\sum p_T\) in cone |
<Lepton>.SumPtCharged |
\(\sum p_T\) of charged particles in cone |
<Lepton>.SumPtNeutral |
\(\sum p_T\) of neutral particles in cone |
Event scalars (both modes)
One value per event (not jagged).
| Branch | Description |
|---|---|
Event.EventNumber |
Original event number from the input file |
Event.TruthHT |
Truth-level scalar \(H_T\) (GeV) |
Event.TruthMET |
Truth-level \(E_{T}^{\text{miss}}\) magnitude (GeV) |
Event.TruthMETx, Event.TruthMETy |
Truth-level \(E_{x}^{\text{miss}}\) and \(E_{y}^{\text{miss}}\) components (GeV) |
Event.PFlowHT |
PFlow-level scalar \(H_T\) (GeV) |
Event.PFlowMET |
PFlow-level \(E_{T}^{\text{miss}}\) magnitude (GeV) |
Event.PFlowMETx, Event.PFlowMETy |
PFlow-level \(E_{x}^{\text{miss}}\) and \(E_{y}^{\text{miss}}\) components (GeV) |
Jet collections (both modes)
One collection per clustering pipeline, named after the pipeline key in the config (e.g., TruthJetsAntiKt05, PFlowJetsAntiKt05).
| Branch | Description |
|---|---|
<JetName>.PT |
Jet transverse momentum (GeV) |
<JetName>.Eta |
Jet pseudorapidity |
<JetName>.Phi |
Jet azimuthal angle (rad) |
<JetName>.D2 |
Energy correlation ratio \(D_2\) (jet substructure) |
<JetName>.C2 |
Energy correlation ratio \(C_2\) (jet substructure) |