Sasha, February 5, 2010
RHIC CNI group is pleased to inform you that RHIC Run 2009 data analysis
for fill-by-fill polarizations is completed. Polarization data along
with some supporting material can be obtained from CNI web page
http://www4.rcf.bnl.gov/~cnipol/pubdocs/Run09Offline/
Pol2009_500gev_blue.dat - Blue sqrt(s)=500 GeV
Pol2009_500gev_yell.dat - Yellow sqrt(s)=500 GeV
Pol2009_200gev_blue.dat - Blue sqrt(s)=200 GeV
Pol2009_200gev_yell.dat - Yellow sqrt(s)=200 GeV
Data files include fill number, polarization, absolute statistical and
systematic uncertainties (assuming not correlated from fill-to-fill).
Global uncertainties, deltaP/P, (assuming correlated for all fills) are
Blue-500gev: 8.3%
Yell-500gev: 12.1%
P(blue+yellow): 9.2%
Blue-200gev: 4.7%
Yell-200gev: 4.7%
And for a product of two beam polarizations, delta(P_B*P_Y)/(P_B*P_Y):
500gev: 18.5%
200gev: 8.8%
A short description of the analysis method and systematic error
explanation are in NOTE_2009_Polarizations_RHIC.txt.
The detailed description of the analysis is in
pC_2009.pdf
Hi Jan,
As for polarization uncertainties, what we gave you (to RHIC Collaborations) are final uncertainties for Run9. The question is: can they be improved. The answer is - probably yes, after very hard work. I do not anticipate any physics results in Run9 which will be limited by polarization uncertainties, therefore we (CNI group) do not plan to work on improving Run9 uncertainties. But currently we're working hard on pC polarimeter upgrade which will help us to get rid of systematics we experienced in Run9 and to provide smaller uncertainties in next RHIC Spin runs. What we already demonstrated is uncertainty ~4-5% (notice 4.7% in Run9 at sqrt(s)=200 GeV) - that's the value we can hope to get in next run. ... But it also depends in RHIC performance (polarization profile, polarization stability etc.)
Regards,
Sasha.