Event Description
The information in each event is stored as a row in a TTree object in the output ROOT file, with the branches documented in the following.
Cells
Note : only cells contained in topoclusters are stored in the output.
cell_layer : Which calorimeter layer the cell belongs to. 0 corresponds to ECAL1 and 5 corresponds to HCAL3
cell_x : x-coordinate of the cell
cell_y : y-coordinate of the cell
cell_z : z-coordinate of the cell
cell_eta : pseudo-rapidity of the cell
cell_phi : azimuthal angle of the cell
cell_e : total energy deposited in the cell
cell_che : total energy deposited in the cell by calorimeter shower component, which was initiated by a charged particle
cell_nue : total energy deposited in the cell by calorimeter shower component, which was initiated by a neutral particle
cell_topo_idx : Topocluster label to which the cell belongs
cell_parent_idx : index of parent particle which contributed the largest fraction of this cell’s energy
cell_conv_el_idx : index of conversion electron which contributed energy to this cell
cell_parent_list : list of parent particles which contributed to this cell’s energy in decreasing order of contribution
cell_parent_energy : list of energies that parent particles contributed to this cell in decreasing order of contribution
Tracks
The tracks are built using the Geant truth information and receive efficiency corrections and smearing of the reconstructed track parameters as specified in the configuration files in COCOA/tracking_configuration
track_parent_idx : index of parent particle corresponding to this track
track_pdgid : the PDG ID of the charged particle which creates the track
track_d0 : track perigee parameter d0, distance of perigee point from z-axis
track_z0 : track perigee parameter z0, distance of perigee point from xy-plane
track_theta : track perigee parameter theta
track_phi : track perigee parameter phi
track_qoverp : track perigee parameter q/p
track_reconstructed : track passes reconstruction efficiency cut
track_in_acceptance : track is inside the detector acceptance (reaches calorimeter and production vertex is inside ITS pixel layer 1)
track_x_layer_i : x-cordinate of the extrapolated track in the i-th calorimeter-layer
track_y_layer_i : y-cordinate of the extrapolated track in the i-th calorimeter-layer
track_z_layer_i : z-cordinate of the extrapolated track in the i-th calorimeter-layer
Nodes (of truth particle record)
node_{} : values for constructing the graph describing the truth particle record
Truth particles
particle_pdgid : vector storing PDG-ID of all the stable truth-particles in the event
particle_isIso : vector storing if the particle is isolated. If true, the value is 1.
particle_pt : transverse momentum of the stable particles
particle_eta : pseudo-rapidity of the stable particles
particle_phi : azimuthal angle of the stable particles
particle_e : energy of the stable particles
particle_prod_x : x-coordinate of the production vertex of the stable particles
particle_prod_y : y-coordinate of the production vertex of the stable particles
particle_prod_z : z-coordinate of the production vertex of the stable particles
particle_track_idx : index of the track corresponding to this particle
particle_eta_extrap_calo : pseudo-rapidity value at the point where the particle enters the calorimeter
particle_phi_extrap_calo : azimuthal angle at the point where the particle enters the calorimeter
particle_eta_extrap_its : same as above, for the end of the ITS
particle_phi_extrap_its : same as above, for the end of the ITS
particle_dep_energy : amount of energy deposited by this particle in the detector
Conversion electrons
conv_el_primary_photon_idx : index of the primary photon which conversion produced this electron
conv_el_q : charge of the conversion electron
conv_el_p{} : momentum in {x,y,z} direction of the conversion electron
conv_el_prod_{} : {x,y,z}-coordinate of the conversion vertex associated with this electron
Topoclusters
topo_idx : index of topocluster (starts at 1)
topo_bary_eta : pseudo-rapidity of the topocluster barycenter
topo_bary_phi : azimuthal angle of the topocluster barycenter
topo_bary_rho : radius in transverse plane of the topocluster barycenter
topo_bary_sigma_eta : width of topocluster in eta dimension
topo_bary_sigma_phi : width of topocluster in phi dimension
topo_e : total energy of topocluster
Superclusters
supercluster_e : total energy of supercluster
supercluster_phi : azimuthal angle of supercluster
supercluster_eta : pseudo-rapidity of supercluster
supercluster_seed_e : energy of topocluster used as seed for the supercluster
supercluster_track_{} : properties of the track associated with the seed used for the supercluster
supercluster_topos : list of topoclusters included in this supercluster
supercluster_track : index of track associated with supercluster seed
supercluster_conv_track : index of conversion track in case of supercluster for photon conversion
supercluster_pdgid : either 22 or +/-11 depending on the truth link of the track or the conversion vertex
supercluster_N : number of clusters included in this supercluster
Graph edges
The calculation of the graph edges is defined in the files in COCOA/config/
track_to_cell_edge_start : list of track indices used as source nodes in track-to-cell edges
track_to_cell_edge_end : list of cell indices used as destination nodes in track-to-cell edges
cell_to_cell_edge_start : list of cell indices used as source nodes in cell-to-cell edges
cell_to_cell_edge_end : list of cell indices used as destination nodes in cell-to-cell edges
particle_to_node_idx : list of truth links to node j which particle i contributed energy to
particle_to_node_weight : list of the fractions of node j’s energy which particle i contributed
Jets
The clustering parameters of the jets are defined in the files in COCOA/config/
true_jet_pt : transverse component of momentum 3-vector of the jet built from truth particle
true_jet_eta : pseudo-rapidity of momentum 3-vector of the jet built from truth particles
true_jet_phi : azimuthal angle of momentum 3-vector of the jet built from truth particles
true_jet_m : mass of momentum 3-vector of the jet built from truth particles
topo_jet_pt : transverse component of momentum 3-vector of the jet built from topoclusters
topo_jet_eta : pseudo-rapidity of momentum 3-vector of the jet built from topoclusters
topo_jet_phi : azimuthal angle of momentum 3-vector of the jet built from topoclusters
topo_jet_m : mass of momentum 3-vector of the jet built from topoclusters
topo_jet_constituents_list : list of topoclusters comprising the topo jet