Algorithm:

The EM tool is based on cal clusters found with L3TCalCluster, which are then matched with CPS 3D clusters and/or tracks. Cuts can be applied via the triggerlist on EM-fraction, isolation, calorimeter cluster widths and all matching-residuals. Multivariate discriminants using all available inputs are under development.

The EM tool can be configured to run in two different modes:
• Calorimeter-based:
  With CALUNP set to NONE, the EM tool will use calorimeter clusters as a basis for matching CPS clusters or tracks. At the minimum, the cal clustering tool must be specified via the CAL parameter.
• Track-based (Road Method):
  To run the road method, CAL has to be set to NONE, and a tracking tool has to be made available via the TRACK parameter.

Results (as currently available in the PhysicsResults-Block of l3fanalyze):

• L3En: Number of electron candidates.
• L3EET: Electron Et.
• L3EEta: Electron Eta.
• L3Ekinex: Electron px.
• L3Ekiney: Electron py.
• L3Ekinez: Electron pz.
• L3EkineT: Electron E.
• L3EvtxX: Electron vertex x.
• L3EvtxY: Electron vertex y.
• L3EvtxZ: Electron vertex z.
• L3Echi2: placeholder for multivariate discriminant.

• L3ECalEt: Cal Cluster Et.
• L3ECalEmfr: Cal Cluster EM fraction.
• L3ECalIso: Cal Cluster isolation.
• L3ECalEta: Cal Cluster Eta (vector sum).
• L3ECalPhi: Cal Cluster Phi (vector sum).
• L3ECalWPhi: Cal Cluster Phi (log-weighted sum).
• L3ECalWR: Cal Cluster R (log-weighted sum).
• L3ECalWZ: Cal Cluster Z (log-weighted sum).
• L3ECalEfr1...L3ECalEfr5: Cal Cluster Energy fractions in layers EM1...EM4,FH1.
• L3ECalWidth1...L3ECalWidth3: Transverse Shower Widths in layers EM1,EM2,EM3.
• L3ECalTrD: delta r between cal cluster and matched track (at EM3). Set to -1 if no match found.
• L3ECalTrDPhi: delta phi between cal cluster and matched track (at EM3).
• L3ECalCpsD: delta eta between cal cluster and matched CPS cluster (at R_CPS). Set to -1 if no match found.
• L3ECalCpsDPhi: delta phi between cal cluster and matched CPS cluster (at R_CPS).
  

• Use the following CPS variables only if match was found (L3ECalCpsD>-0.5)
• L3ECpsE: CPS-3D-Cluster energy.
• L3ECpsPhi: CPS-3D-Cluster phi position.
• L3ECpsZ: CPS-3D-Cluster z position.
• L3ECpsE1,L3ECpsE2,L3ECpsE3: CPS-SLC Energy in layer 1,2,3.
• L3ECpsN1,L3ECpsN2,L3ECpsN3: CPS-SLC number of strips above threshold in layer 1,2,3.
• L3ECpsRes: 
• L3ECpsChi2: 
• L3ECpsTrD: delta z between CPS cluster and matched track (at R_CPS). Set to -1 if no match found.
• L3ECpsTrDPhi: delta phi between CPS cluster and matched track (at R_CPS).
  

• Use the following track variables only if match was found (L3ECalTrD>-0.5 or L3ECpsTrD>-0.5)
• L3ETrDca: Track DCA.
• L3ETrPhi: Track Phi (at origin).
• L3ETrPhiR: Track Phi (at R_CPS).
• L3ETrPtinv: Track inverse pt.
• L3ETrRinv: Track inverse R.
• L3ETrTanl: Track tan lambda.
• L3ETrZ: Track z (at origin).
• L3ETrZR: Track z (at R_CPS).

Tool Parameters (passed in via trigger list, for a list check the Database):

• CAL:  the reference to the cal clustering tool.
• CALUNP:  the reference to the cal unpacking tool.
• CPS:  the reference to the cps clustering tool (can be switched off by specifying "none").
• TRACK:  the reference to the track finding tool (can be switched off by specifying "none").
• EMFR: Only electron candidates with EM fraction above EMFR will be returned.
• isolation: Only electron candidates with isolation below this cut will be returned.
• Width_EM1: Only electron candidates with shower width in EM1 below this cut will be returned.
• Width_EM2: Only electron candidates with shower width in EM1 below this cut will be returned.
• Width_EM3: Only electron candidates with shower width in EM1 below this cut will be returned.
• Cal_Cps_dphi: Window size in phi for matching cal clusters and cps clusters.
• Cal_Cps_dz: Window size in z for matching cal clusters and cps clusters.
• Cal_Cps_deta: Window size in eta for matching cal clusters and cps clusters.
• Cal_Cps_dcut: Maximum distance (currently defined as delta eta) between cal cluster and best cps match in window. EM candidates without a match passing this cut will not be returned.
• Cps_Track_dphi: Window size in phi for matching cps clusters and tracks.
• Cps_Track_dz: Window size in z for matching cps clusters and tracks.
• Cps_Track_dcut: Maximum distance (currently defined as delta z) between cps cluster and best track match in window. EM candidates without a match passing this cut will not be returned.
• Cal_Track_dphi: Window size in phi for matching cal clusters and tracks.
• Cal_Track_deta: Window size in eta for matching cal clusters and tracks.
• Cal_Track_dcut: Maximum distance (currently defined as delta r) between cal cluster and best track match in window. EM candidates without a match passing this cut will not be returned.
• CHI2: Place holder for cut on discriminant.
• EMSEED: Currently not used.

RCP Switches:

none at the moment