[G14_run] From Dao Ho: question about electron beam polarization with negative sign

[daoh at andrew.cmu.edu]

Dear all,

In the
https://clasweb.jlab.org/rungroups/g14/wiki/index.php/Beam_Polarization_%28Circ.%29
page, the Beam polarization measurements table (this is an updated one)
shows negative beam polarization as well as positive one (the ones in
bold). I discovered that silver 3,4 and gold2 both have negative sign
(-76.2% and -83.4% respectively), while silver 5a and 5b both have
positive sign (+88.8%). My question is whether we have taken into account
of this difference in sign when computing the beam helicity (i.e, during
cooking or analysis). For my case, I always used positive 88% for the beam
polarization regardless of whatever run periods.

Another observation shows that silver 1 and 2 have opposite sign comparing
to silver 3, but I don't remember me comparing the E asymmetry between the
two periods with either silver3 or gold2 (Tsuneo might have done that).

Anyway, I hope this is the sign problem in silver 5 period that we have
been chasing after.
Let me know what you think.
Sincerely,
Dao Ho