Privacy and Security Notice

eloss_check

Energy loss correction 02/16/06


The energy loss of the scattered electron and proton were corrected for in the engine.  In s_physics.f there are the lines:

      ssenergy = ssenergy + sseloss
      ssp = sqrt(ssenergy**2-spartmass**2)

The ssp here is written to the coin ntuple without any further corrections (cuts may be applied).   The same is also true for the hms.  The size of the correction was approximately an MeV.

Therefore, the hee'p analysis incorporated these offsets correctly, except that SIMC applied energy loss and did not correct for it.  SIMC was used to determine the size of the shifts in the peaks due to radiation.  The size of the shift may change slightly when energy loss is included.  Therefore, the procedure was modified to include eloss corrections in SIMC.

Notes
  1. The transparency results need to be calculated again because SIMC had energy loss, but did not correct for it.  Meanwhile, the data had eloss but corrected for it.
  2. Another change in the heep procedure was to turn all offsets in SIMC in the spec_offset section to zero.
  3. Another change in the heep procedure was to use the beam energy without energy loss in the target as the beam energy in SIMC.  SIMC does this step.