Link to src file:


Cut based Marlin processor for event selection by initial particle using topological parameters of event. 


eSum - Energy sum per event

nHits - Number of hits per event

r - Shower radius

zcog - Center of gravity in z

frac25 - Fraction of energy in first 25 layers

st - Shower start layer number - currently is found by MIP criterium, function from FindStartAndPrimaryTrack

nClusters - number of clusters in first layers


  • Reconstructed slcio file (with StdVariablesProcessor output!)
  • Cluster collection ( 2D clustering )
  • Layer to cluster relation collection


  • Events of any type can be thrown from Marlin chain according to IDMode parameter
  • ROOT file to check your cuts (optional)

    Contains 5 trees with ID variables:
    • IDtree - all events
    • had_IDtree - hadron events
    • mu_IDtree - muon-like events
    • ele_IDtree - electron events
    • rej_IDtree - rejected events 

Important parameters:

  • Beam energy in GeV - using only to find shower start layer
  • IDMode: 0 - keep all, 1 - only hadron events, 2 - only muon-like events, 3 - only electron events
  • Event filtering:
    • Minimum number of hits - to reject empty events
    • Number of first layers to calculate cluster spread
    • Maximum cluster spread in first layers to reject multi-particle and early showering events

Example steering:


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