Calorimeter calibration

Hajrah and Alex, from Edinburgh, found in their analyses a mass distribution of the Higgs quite high and wide when the mass is reconstructed from the b jets. That led us to think if there is a problem with the calibration. As an exercise I ran the PandoraPFACalibrator processor and comparing the processors SimpleCaloDigi and MokkaCaloDigi, using the detector model LDC01_05Sc I found that for the ECAL calibration the energy distribution of 10 GeV photons is fine for both processors. But for the 10 GeV KL using SimpleCaloDigi the energy distribution is wide and peaks at an energy higher than 10 GeV.

Here are the plots for the energy distribution of the

• photons 
  
• kaons
  

The solid black line comes from MokkaCaloDigi; dashed red line comes from SimpleCaloDigi.

We are using SimpleCaloDigi in our reconstruction. That might be the reason of the wrong mass distribution of the Higgs candidates. The next step is to check the calibration constants for LDC01Sc, as this is the model used for our samples, change to MokkaCaloDigi and see if the results improve.