[Frost] Official Target/Beam Pol. Table

[lcasey at jlab.org]

Hi all,

I know we've been through this a thousand times, but I can't really let it
drop until we have some official table of consistent polarization
direction values that works not just for E, but also for recoil double
polarization observables that depend only on the target or beam
polarization direction.

Jo has already gone over the target polarization directions a second time.
I don't think that needs to be done again, but we need to make sure the
meaning of the helicity bit in terms of photon circular polarization is
consistent with both Jo's target polarization direction and the overall
sign of E.  In this spirit, I've edited the table I had initially put in
when we were all trying to work out the helicity assigment to reflect what
I think the table should look like. Note that for the first three run
groups I have removed the negative sign from the electron beam
polarization and changed the sign of the target polarization to agree with
Jo's table.  It stands to reason that if the target direction is incorrect
here and the E sign is correct, then the odd change in the meaning of the
helicity bit between 1.6 and 2.4 GeV data must also be incorrect.

That's the simple part, I think.  There's one more thorny issue, which I
signify with question marks.  It was never suggested that the electron
polarization direction was negative for group 5. Nonetheless, the signs
from Jo's table (+/-) and Steffen's table (-/-) are different here.  In
this case perhaps the electron beam polarization should be changed to
negative.  At any rate, I'd like to talk about it and making an official
table tomorrow.

Peace,

Liam