Preliminary Look at some of the MC runs

1
Preliminary Look at some of the MC runs

• Stefan Funk
• May 2, 2006

2
Typo in the MC runs Web Site

• Found typos in the Logging of the MC runs on the
  web-site
• The plot shows Tkr1Z0 vs Tkr1X0
• run 0002 was taken at an angle whereas run 0003
  seems to be taken at 0 degrees
• opposite to what is reported on the web-site
• Thanks for fixing that Tom

3
MC Vertical Displacement of Beam

• Vertical displacement of the beam with respect to
  the calibration unit
• indicates that the position of the beam is chosen
  such that we directly shoot into a dead spot (see
  plot)
• not optimal and will make it much harder to find
  the converted photons in the positron runs.
• Should we use a vertical and horizontal
  displacement of the beam (e.g. of 27mm) to not
  hit a dead region of the tracker (27mm so we just
  move to the next calorimeter crystal)?

4
MC Position of the dump

• Horizontal distance of the dump from the beam 3
  cm for the current setup
• We seem to be cutting some part of the beam (this
  is for a 2 GeV beam probably worse for a lower
  energy beam).

5
Some comments

• For studying the positrons
• would be nice to have an electron runs of similar
  length and conditions (i.e. energy, etc).
• Could we add some variables to the output
  Merit-Tuple?
• the MC true id, position and momentum of the
  particles arriving at the reporting plane
• of course this will be a vector of variable
  length, depending on the event
• For the moment the particle id, position and
  momentum
• of the two highest energy particles would add a
  great value
• the energy of the incident particle
• the value of magnetic field
• Maybe we could start collecting a list of wishes
  and add them for the next generation of MC runs?

6
MC Started looking into angular resolution

• Take angular distance between incoming electron
  and direction of outgoing gamma (MC truth)
• Left plot angular distance vs energy
• Right plot 68 containment radius in the energy
  bins
• Black using the information provided by the two
  silicon detectors in front of the magnet
• Red not using this information