[Frost] Systematics for target offset

[Michael Dugger]

Hi,

I know that many from the FROST group are preparing for talks, but I 
think it would be good to start thinking about systematics for g9b.

For g9b data, one of the systematics that will effect all groups is that 
associated with the target offset determination. Because this systematic 
effects all groups, we need to agree upon the target offset and the 
uncertainty in our agreed upon value.

Next FROST meeting I will discus the systematics of T and F associated 
with a systematic shift in the target offset. My preliminary calculations 
(that I need to check), suggest that a 5 degree shift in the offset will 
only give a 0.4% systematic in T, but can -in special situations- give a 
systematic in F of about 9%. More realistically the average systematic in 
F should be more like 5% or less. Of course, I'll have to check to make 
sure I did not do anything stupid when I preformed these preliminary 
calculations.

The important thing is that we come up with some strategy that is 
acceptable to all groups. It seems to me that the best way for us to 
measure the offset will be from the circular beam data. To my knowledge, 
the groups looking at circular g9b data are:

* ASU (Reactions: pi+ n, eta p)
* CUA (Reactions: omega p, K+ Lambda)
* South Carolina (Reaction: pi0 p)

This list does not look complete to me. I think I have missed someone.

If I remember correctly, FSU has Priya looking at the linear g9b data. I 
don't know who is investigating the 2-pi reactions using circular g9b. If 
anyone is looking at g9b circular data, and your reaction is not in the 
above list, please let me know.

At this time, I just want to identify the groups that have the best chance 
of measuring the offset, and start talking about how we can go about 
estimating the systematics. Once everyone has come back from giving their 
talks, we can start working on obtaining an agreed upon value of the 
target offset.

Take care,
Michael