RootTreeWriter

General event variables:

One value per event

• runNumber (int)
  Same for all events in one run
• eventNumber (int)
  Starting at 0 and going to number of events -1
• eventTime (float) 
  BIF timestamp in unix time
  
• ahc_iEvt (int)
  Starting at 1 and going to number of events (cross-check for eventNumber)
• ahc_nHits (int)
  Number of hits per event
• ahc_nLayers (int)
  Needs work: currently 100 for all events, meant to be the available number of layers from database
• ahc_st (int)
  Position of shower start
• ahc_MCst (int)
  Position of shower start - based on MC truth information
• ahc_energySum (float)
  Summed up energy of all hits above threshold per event in MIP: 
  $//<![CDATA[ \begin{array}{l}ahc\_energySum = \sum_{i=0}^{ahc\_nHits - 1} ahc\_hitEnergy_i\end{array} //]]>$
• ahc_energyDensity (float)
  Energy of all hits in event divided by tile surface in MIP/mm²
  $//<![CDATA[ \begin{array}{l}ahc\_energyDensity = \sum_{i=1}^{ahc\_nLayers} \left( \sum_{j=0}^{ahc\_nHitsPerLayer_i -1} \frac{ahc\_hitEnergy_j}{{ahc\_cellSize_j}^2} \right)\end{array} //]]>$
• ahc_radius (float)
  Mean shower radius of an event in mm
  $//<![CDATA[ \begin{array}{l}ahc\_radius = \frac{\sum_{i=0}^{ahc\_nHits - 1} ahc\_hitRadius_i}{ahc\_nHits}\end{array} //]]>$
  
• ahc_radiusEw (float)
  Mean energy weighted shower radius using the layer-wise center of gravity in X and Y in mm
  $//<![CDATA[ \begin{array}{l}ahc\_radiusEw = \frac{\sum_{i=1}^{ahc\_nLayers} \left( \sum_{j=0}^{ahc\_nHitsPerLayer_i-1} \frac{ahc\_hitEnergy_j}{{ahc\_cellSize_j}^2} \cdot \sqrt{{ \left( ahc\_cogXPerLayer_i-ahc\_hitPos[0]_j \right) }^2 + { \left( ahc\_cogYPerLayer_i-ahc\_hitPos[1]_j \right) }^2} \right)}{ahc\_energyDensity}\end{array} //]]>$
• ahc_cogX (float)
  Center of gravity of event in X (perpendicular to beam axis) in mm with respect to the center of the detector
  $//<![CDATA[ \begin{array}{l}ahc\_cogX = \frac{\sum_{i=0}^{ahc\_nHits - 1} ahc\_hitPos[0]_i \cdot ahc\_hitEnergy_i}{ahc\_energySum}\end{array} //]]>$
• ahc_cogY (float)
  Center of gravity of event in Y (perpendicular to beam axis) in mm with respect to the center of the detector
  $//<![CDATA[ \begin{array}{l}ahc\_cogY = \frac{\sum_{i=0}^{ahc\_nHits - 1} ahc\_hitPos[1]_i \cdot ahc\_hitEnergy_i}{ahc\_energySum}\end{array} //]]>$
• ahc_cogZ (float)
  Center of gravity of event in Z (in beam direction) in mm with respect to the beginning of the first layer
  $//<![CDATA[ \begin{array}{l}ahc\_cogZ = \frac{\sum_{i=0}^{ahc\_nHits - 1} ahc\_hitPos[2]_i \cdot ahc\_hitEnergy_i}{ahc\_energySum}\end{array} //]]>$

Layer-wise event variables:

Array of size of ahc_nLayers per event 

• ahc_energyPerLayer (float)
  Energy sum of all hits in one layer per event in MIP
• ahc_energyPerLayer_err (float)
  Needs work: not yet saved in slcio files
• ahc_nHitsPerLayer (int)
  Number of hits in one layer per event
• ahc_cogXPerLayer (float)
  Center of gravity in X direction in mm in one layer per event 
• ahc_cogYPerLayer (float)
  Center of gravity in Y direction in mm in one layer per event
• ahc_radiusPerLayer (float)
  Mean shower radius of an event in mm per layer
  
• ahc_radiusEwPerLayer (float)
  Mean energy weighted shower radius of an event per layer in mm

Hit variables:

Array of size of ahc_nHits per event

• ahc_hitEnergy (float)
  Pedestal-subtracted and MIP-calibrated energy of the hit
• ahc_cellSize (int)
  Side length of hit scintillator tile in mm
• ahc_hitPos (float)
  3 arrays of size ahc_nHits, one each for X, Y and Z: ahc_hitPos[0] is the position in X direction, ahc_hitPos[1] is Y, ahc_hitPos[2] is Z
  Hit position in mm in X, Y and Z with respect to the center of the detector (for X, Y) or the beginning of the first layer (for Z)
• ahc_hitI (int)
  Number of hit scintillator tile in X direction (going from 1 to 24)
• ahc_hitJ (int)
  Number of hit scintillator tile in Y direction (going from 1 to 24)
• ahc_hitK (int)
  Number of hit scintillator tile in Z direction (corresponds to the layer number, going from 1 to ahc_nLayers)
• ahc_hitCellID (int)
   Encoded IJK information of the hit
• ahc_hitRadius (float)
  Radial distance from center of gravity of event in x and y in mm
  $//<![CDATA[ \begin{array}{l}ahc\_hitRadius = \sqrt{{\left( ahc\_cogX - ahc\_hitPos[0] \right)}^2+{\left( ahc\_cogY - ahc\_hitPos[1] \right)}^2}\end{array} //]]>$
• ahc_hitEnergyDensity (float)
  Hit energy divided by surface of hit scintillator tile in MIP/mm²
  $//<![CDATA[ \begin{array}{l}ahc\_hitEnergyDensity = \frac{ahc\_hitEnergy}{{ahc\_cellSize}^2}\end{array} //]]>$
• ahc_hitType (int)
  Definition: GainBit*100 + memoryCell 
  Information on high gain (1) / low gain (0) and memory cell (0 to 15)
• ahc_hitTime (float)
  reference-subtracted and ns-calibrated time of the hit 

5-layer variables:

• Variables for first five layers
• Only counts hits outside a radius of 280mm except for the center of gravity calculation