[Shms_users] Hall C 12 GeV software update (mailing list & request for additional info)

[Rolf Ent]

>        - compare track reconstruction event-by-event
>          - It would be disconcerting if there are significant differences
>            between what the "Hall A" tracking algorithms generate and what
>            the FORTRAN analyzer ends up with.  I would like to think there
>            is minimal special case "magic" in either tracking codes.
>
> Keep in mind that the tracking algorithm for the Hall A HRS has been
> specifically written for our set of VDCs. I don't think you have VDC 
> reconstruction in your Fortran analyzer, or do you? Even if you do, I do 
> think there may very well be "special case magic". I doubt such a 
> comparison would work out of the box. But yes, we did the same thing,
> we compared Fortran and C++ tracking output in exhaustive detail - after
> we wrote the C++ tracking code from scratch.

 	Ole is correct, it is a non-starter to assume the tracking codes
will give similar results given that the Hall A setup uses VDCs. Even
more, the Hall C tracking analysis has been painstakingly optimized with
various "pruning" additions to have a well-known tracking efficiency for
very high rates within the spectrometer, with many bells and whistles how
to check it.  Given this, my point of view would be that the starting
point to optimize for the precision L/T program in Hall C should be the
robust Hall C tracking algorithm. Maybe one could argue we should update
the documentation if for instance Eric Christy's tracking note is not
readily accessible, and adding sections from Vladas Tvaskis' thesis.
Don Geesaman did a good job doing the initial documentation.

 					best regards,	Rolf