Minutes of the muon software meeting April 16 2003, taken by David

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We discussed the upcoming software releases. 

  4.10.X will be used on the farms.  We are currently 
  working the bugs and major problems out of this series 
  of releases, but otherwise it is frozen.  4.10.2 has bugs 
  that make it not suitable for general release.  4.10.3 
  will be released soon.

  4.11.X will be a simulation release. The first release in
  this series will be tagged on Friday.

  4.12.X will be a the physics release for the summer conferences.
  Tagging will be in about 1 month.

Everyone is encouraged to test the muon reconstruction in
these releases to validate it as quickly as possible.

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Slava gave an update on his work on the chi2 calculation.
He is developing dx corrections and chi2 widths to be used
to calculate chi2 values for muons.  He is studying the 
variation in phi, eta, and pt. The central values of the 
DX distribution vary on order 1 cm for low pt muons.  He 
is working on one set of parameterizations that can be used 
with 4.9.1 muons and one set of parameterizations that can 
be used with 4.10.X muons. Slava plans to give a more detailed 
report on his work in the upcoming meetings.

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Camille showed some preliminary studies using the new versions
of the software.  The IMU is the part of the muon software that
changed the most since release 4.8.4.  She was running the 
development versions of Muon and MuonMods packages in a 
4.9.1hpt1 test release.  She was looking at a sample of 335 
candidate Z events made with 4.8.4.  When reconstructing these
events with the new software, she found some BMU muons vanish 
and some new ones are reconstructed.  Many of the ones that 
fail to reconstruct are in the tails of the DX distribution 
so are probably not real Z's. Examining the differences in 
phi, eta, EM, HAD, showed no areas where the differences 
were concentrated.  So far she seems to think things are OK.  
But plans to continue her studies.