The "Downstream Aluminum Problem"
The cos(theta) distribution changes, in places at the few percent
level, when an aluminum plate is placed downstream of the
detector. Little such change is seen in Geant simulations.
This page describes the quest to find out why (and fix it).
- "Downstream
Aluminum in Geant" slides
- Slides from the October 2003 Collaboration Meeting,
summarizing the "Downstream Aluminum Problem".
- Decay
deltas and downstream aluminum and
Downstream
Aluminum Effects and Delta Removal
- Could the difference be in the way Geant generates delta
particles? (Indications are: No.)
- Downstream
Aluminum and the Oct. 23 Tune Change
- The beam tune was changed on 23 October 2002 (due to
changes in power supplies etc. to the beamline elements).
Did this change affect the cos(theta) spectrum between the
"standard muons" dataset and the "downstream aluminum"
dataset? (Indications are that, while there are
effects, they are not enough to explain the "Downstream
Aluminum Problem.)
- Hitting
DS Al in Geant
- Checking whether the positrons are actually striking the
aluminum in Geant and generating secondary particles
(photons, deltas, etc). (They are.)
Last updated 03.10.30 by Robert MacDonald.
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