PFlow Jets Variable#

The following variables are defined:

Jet variables#

Variable Name	Description
`HadronConeExclTruthLabelChildPdgId`
`HadronGhostTruthLabelChildPdgId`
`absEta_btagJes`	Jet $
`eta_btagJes`	Jet $\eta$ in input (D)AOD.¹
`jetPtRank`	Rank of jet in $p_{\rm T}$ -ordered list in event. Rank 0 corresponds to highest- $p_{\rm T}$ jet.
`primaryVertexDetectorZ`
`pt_btagJes`	Jet $p_{\rm T}$ in input (D)AOD.¹
`scalarSumTrackPt`
`energy`	Energy of calibrated jet.
`eta`	Calibrated $\eta$ of jet.
`mass`	Mass of calibrated jet.
`phi`	Jet $\phi$ .
`pt`	Calibrated $p_{\rm T}$ of the jet. Flavor tagging is generally quantified in terms of this variable.
`NNJvt`	Jet vertex NN tagger score (used for pile-up rejection).
`isJvtHS`	Truth hard-scatter label. Truth information! Do not use for training!
`isJvtPU`	Truth pile up label. Truth information! Do not use for training!
`actualInteractionsPerCrossing`	Number of interactions per bunch crossing ( $\mu$ ) for the bunch crossing this jet was associated to.
`averageInteractionsPerCrossing`	Number of interactions per bunch crossing ( $\mu$ ) averaged over this lumi block.
`eventNumber`	Event number of the event the jet is associated with.
`mcEventWeight`	Event weight of MC simulated event. Truth information! Do not use for training!
`nPrimaryVertices`	Number of reconstructed primary vertices in this event.
`GhostBHadronsFinalCount`	number of associated b hadrons, based on whether they fall into the area clustered with the jet. Truth information! Do not use for training!
`GhostBHadronsFinalPt`	pt of associated b hadrons. Truth information! Do not use for training!
`GhostCHadronsFinalCount`	number of associated c hadrons. Truth information! Do not use for training!
`HadronConeExclExtendedTruthLabelID`	more detailed version of the HadronCone algorithm, with labels for double b-jets: 55 (double b-jets), 54 (bc jet). Truth information! Do not use for training!
`HadronConeExclTruthLabelChildLxy`	Decay radius of the child hadron of the labelling particle used for HadronConeExclTruthLabelID. (i.e. the c-hadron inside a b-to-c decay). Truth information! Do not use for training!
`HadronConeExclTruthLabelChildPt`	PDGID of the child hadron of the labelling particle used for HadronConeExclTruthLabelID (i.e. the c-hadron inside a b-to-c decay). Truth information! Do not use for training!
`HadronConeExclTruthLabelDR`	dR(truth, jet) for the labelling particle used for HadronConeExclTruthLabelID. Truth information! Do not use for training!
`HadronConeExclTruthLabelID`	jet label, using a geometric cone around the jet rather than the jet clustering algorithm. If a parton with a transverse momentum of more than 5 GeV is found within dR(q, jet) < 0.3 of the jet direction, the jet is labelled as a jet with the parton's flavour. The label should be one of: 0 (light jet), 4 (charm jet), 5 (bottom jet), or 15 (tau jet). Results should be similar to the ghost labeling. Truth information! Do not use for training!
`HadronConeExclTruthLabelLxy`	Decay radius of the labelling particle used for HadronConeExclTruthLabelID. Truth information! Do not use for training!
`HadronConeExclTruthLabelPdgId`	PDGID of the labelling particle used for HadronConeExclTruthLabelID. Truth information! Do not use for training!
`HadronConeExclTruthLabelPt`	Transverse momentum of the labelling particle used for HadronConeExclTruthLabelID. Truth information! Do not use for training!
`HadronGhostExtendedTruthLabelID`	more detailed version of the HadronGhostTruthLabelID, with labels for jets with two hadrons: 55 (double b-jets), 54 (bc jet), 44 (cc jet). Truth information! Do not use for training!
`HadronGhostTruthLabelChildLxy`	Decay radius of the child hadron of the labelling particle used for HadronGhostTruthLabelID. (i.e. the c-hadron inside a b-to-c decay). Truth information! Do not use for training!
`HadronGhostTruthLabelChildPt`	PDGID of the child hadron of the labelling particle used for HadronGhostTruthLabelID (i.e. the c-hadron inside a b-to-c decay). Truth information! Do not use for training!
`HadronGhostTruthLabelDR`	dR(truth, jet) for the labelling particle used for HadronGhostTruthLabelID. Truth information! Do not use for training!
`HadronGhostTruthLabelID`	Jet flavour label using ghost associated hadrons. Labelling hadrons are required to have $p_T > 5$ GeV. The label should be one of: 0 (light jet), 4 (charm jet), 5 (bottom jet), or 15 (tau jet). Truth information! Do not use for training!
`HadronGhostTruthLabelLxy`	Decay radius of the labelling particle used for HadronGhostTruthLabelID. Truth information! Do not use for training!
`HadronGhostTruthLabelPdgId`	PDGID of the labelling particle used for HadronGhostTruthLabelID. Truth information! Do not use for training!
`HadronGhostTruthLabelPt`	Transverse momentum of the labelling particle used for HadronGhostTruthLabelID. Truth information! Do not use for training!
`PartonTruthLabelDR`	dR(parton, jet) of the labelling parton. Truth information! Do not use for training!
`PartonTruthLabelID`	Parton level flavour label, based on PDGID. The highest energy parton is used to label the jet. Truth information! Do not use for training!
`PartonTruthLabelPt`	pT of the labelling parton. Truth information! Do not use for training!
`GN2v01_pb`	Output from the GN2, $b$ -jet probability.²
`GN2v01_pc`	Output from the GN2, $c$ -jet probability.²
`GN2v01_pu`	Output from the GN2, light-jet probability.²
`n_tracks`	Number of tracks associated to the jet
`softMuon_dR`	Soft muon tagger output
`softMuon_eta`	Soft muon tagger output
`softMuon_ip3dD0`	Soft muon tagger output
`softMuon_ip3dD0Significance`	Soft muon tagger output
`softMuon_ip3dD0Uncertainty`	Soft muon tagger output
`softMuon_ip3dZ0`	Soft muon tagger output
`softMuon_ip3dZ0Significance`	Soft muon tagger output
`softMuon_ip3dZ0Uncertainty`	Soft muon tagger output
`softMuon_isDefaults`	Soft muon tagger output
`softMuon_momentumBalanceSignificance`	Soft muon tagger output
`softMuon_pTrel`	Soft muon tagger output
`softMuon_phi`	Soft muon tagger output
`softMuon_pt`	Soft muon tagger output
`softMuon_qOverPratio`	Soft muon tagger output
`softMuon_scatteringNeighbourSignificance`	Soft muon tagger output

Track variables#

Variable Name	Description
`ftagTruthSourceLabel`
`valid`	valid flag, for more robust selection, true for any track that is defined
`d0`	transverse impact parameter relative to PV. (aka distance of closest approach of the track to the primary vertex point in the r-phi projection). Defined here³
`d0Uncertainty`	uncertainty on track d0
`phiUncertainty`	uncertainty on track phi
`pt`	track transverse momentum
`qOverP`	track charge divided by momentum magnitude
`qOverPUncertainty`	uncertainty on track qOverP
`thetaUncertainty`	uncertainty on track theta
`z0RelativeToBeamspot`	longitudinal impact parameter projected onto the direction perpendicular to the track, relative to beamspot
`z0RelativeToBeamspotUncertainty`	uncertainty on track z0RelativeToBeamspot
`z0SinTheta`	longitudinal impact parameter projected onto the direction perpendicular to the track, relative to the PV. Defined here³
`z0SinThetaUncertainty`	uncertainty on track z0SinTheta
`numberOfInnermostPixelLayerHits`	number of hits in the IBL: could be 0, 1, or 2
`numberOfInnermostPixelLayerSharedHits`	number of shared hits (contributing to the track fit and to another track) in the IBL
`numberOfInnermostPixelLayerSplitHits`	number of split hits in the IBL
`numberOfNextToInnermostPixelLayerHits`	number of hits in the next-to-innermost pixel layer: could be 0, 1, or 2
`numberOfPixelHits`	combined number of hits in the pixel layers (including the IBL)
`numberOfPixelSharedHits`	number of shared hits (contributing to the track fit and to another track + not marked as split hit) in the pixel layers (including the IBL)
`numberOfPixelSplitHits`	number of split hits in the pixel layers (including the IBL; split hit = hit is identified as being created by multiple charged particles during ambiguity solver stage at pattern recognition level)
`numberOfSCTHits`	combined number of hits in the SCT layers (since 2 strip hits are required for a full SCT spacepoint, this number is divided by two in the track selection)
`numberOfSCTSharedHits`	Number of shared hits (contributing to the track fit and to another track) in the SCT layers (since 2 strip hits are required for a full SCT spacepoint, this number is divided by two in the track selection)
`deta`	pseudorapidity distance between track and jet
`dphi`	azimuthal angle distance between track and jet
`ptfrac`	fraction of the jet pt carried by the track
`lifetimeSignedD0`	The lifetime-signed transverse impact parameter.⁴
`lifetimeSignedD0Significance`	The lifetime-signed track $d_0$ significance ( $d_{0} / \sigma_{d_{0}}$ ).⁴
`lifetimeSignedZ0SinTheta`	The lifetime-signed longitudinal impact parameter, multiplied by $\sin \theta$ .⁴
`lifetimeSignedZ0SinThetaSignificance`	The lifetime-signed track $z_0$ significance ( $z_{0} \sin \theta / \sigma_{z_{0} \sin \theta}$ ).⁴
`AMVFWeightPV`	compatability of the track with the primary vertex if the track was used in the primary vertex fit (0 if the track was not used in the primary vertex fit)
`JFVertexIndex`	index of JF vertex if this track was used in the construction of a JF vertex (defaults to -2)
`SV1VertexIndex`	index of SV1 vertex if this track was used in the construction of a SV1 vertex (defaults to -2)
`leptonID`	+-11 if the track was used in the reconstruction of an electron. +-13 for muon. If a track was not used in the reconstruction of a electron or muon, then 0.
`ftagTruthBarcode`	generator level truth barcode of the truth particle linked to this track (if one exists), used for linking between different objects
`ftagTruthOriginLabel`	Truth origin of the track.⁵
`ftagTruthParentBarcode`	barcode of the parent B/C hadron (if one exists) of the truth particle linked to this track (if one exists). If no truth particles are linked to this track a value of -1 is returned. A value of -2 indicates that there is a truth particle linked to the track but it is not a B/C hadron. Used for linking to particles in the `truth_hadrons` dataset.
`ftagTruthTypeLabel`	truth type of the track (NoTruth=0, Other=1, Pion=2, Kaon=3, Electron=4, Muon=5, Photon=6). Defined here
`ftagTruthVertexIndex`	truth vertex index of the track. 0 is reserved for the truth PV, any SVs are indexed arbitrarily with a int >0. Truth vertices within 0.1mm are merged.

Truth variables#

Variable Name	Description
`Lxy`
`barcode`
`charge`
`decayVertexDEta`
`decayVertexDPhi`
`decayVertexX`
`decayVertexY`
`decayVertexZ`
`deta`
`dphi`
`dr`
`energy`
`eta`
`flavour`
`ftagTruthParentBarcode`
`mass`
`pdgId`
`phi`
`pt`
`valid`

Truth variables#

Variable Name	Description
`mass`
`valid`	validity flag, for more robust selection, true for any truth particle that is defined
`Lxy`	truth particle decay displacement⁶
`charge`	truth particle charge
`decayVertexDEta`	truth particle decay $\eta$ offset, relative to the jet axis⁶
`decayVertexDPhi`	truth particle decay $\phi$ offset, relative to the jet axis⁶
`decayVertexX`	X component of the truth particle decay displacement⁶
`decayVertexY`	Y component of the truth particle decay displacement⁶
`decayVertexZ`	Z component of the truth particle decay displacement⁶
`deta`	pseudorapidity distance between truth particle and jet
`dphi`	azimuthal angle distance between truth particle and jet
`dr`	truth particle dR(particle, jet)
`energy`	truth particle energy
`eta`	truth particle pseudorapidity
`phi`	truth particle azimuthal angle
`pt`	truth particle transverse momentum
`barcode`	generator level barcode of the truth particle, used to link to objects in other datasets
`flavour`	5 if the truth particle is a B hadron, 4 if the truth particle is a C hadron, -1 otherwise.
`ftagTruthParentBarcode`	barcode of the parent B hadron (if one exists) of the truth particle.
`pdgId`	truth particle pdgId

Please reach out to the flavour tagging group if you have any questions:

ATLAS FTAG mattermost channel

In production, flavor tagging algoirhtms run before the final jet calibration is applied.The jet energy scale at this stage is set by the jet calibration which is applied when jets are built.Jets saved in DAODs are calibrated to this scale as well.For consistency, we use this jet energy scale in the training as well. ↩↩
This is a high-level output from a neural network. It should not be considered a stable input to design new taggers. ↩↩↩
The conventional $d_0$ takes the sign of $(\vec{p}_0 \times \vec{d}_0) \cdot \hat{z}$ , where $\vec{d}_0$ is the transverse track displacement at the closest approach to the primary vertex and $\vec{p}_0$ is the momentum at that point. ↩↩
The lifetime signed impact parameters are given a positive sign if $|\phi_0 - \phi_{\mathrm{jet}}| < \pi / 2$ and a negative sign otherwise, where $\phi_0$ and $\phi_{\mathrm{jet}}$ are the $\phi$ components of the track displacement and the jet momentum, respectively. ↩↩↩↩
Tracks labels: 0 = pileup, 1 = fake, 2 = prompt, 3 = from $b$ -hadron, 4 = from $c$ child of a $b$ hadron, 5 = from $c$ -hadron, 6 = from $\tau$ lepton, 7 = from other secondary decay. See InDetTrackTruthOriginDefs for ore information. ↩
For truth variables the displacement is defined as the decay vertex position, relative to the production vertex for the simulated event. ↩↩↩↩↩↩