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CNI polarizations in Run09: Summary

CNI polarizations in Run09: Summary. A.Bazilevsky For the RHIC CNI Group March 26, 2010 RSC meeting. Run9 results. Released on Feb 4, 2010: http://www4.rcf.bnl.gov/~cnipol/pubdocs/Run09Offline/ Gives: Fill#, Polarization, Stat. error, Syst. Error Global syst. errors (to all fills)

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CNI polarizations in Run09: Summary

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  1. CNI polarizations in Run09:Summary A.Bazilevsky For the RHIC CNI Group March 26, 2010 RSC meeting

  2. Run9 results • Released on Feb 4, 2010: • http://www4.rcf.bnl.gov/~cnipol/pubdocs/Run09Offline/ • Gives: • Fill#, Polarization, Stat. error, Syst. Error • Global syst. errors (to all fills) • Short analysis description: • NOTE_2009_Polarizations_RHIC.txt • Detailed analysis description: • pC_2009.pdf

  3. Briefly • Hjet: • Absolute beam polarization • Continuously running in a fill • Absolute stat. uncertainty in a fill: 0.04-0.07 • ~50% fills at s=500 GeV and ~80% fills at s=200 GeV • Statistics accumulated in many fills used to normalize pC • pC (two polarimeters in a ring): • 3-4 measurements in a fill (every 2-3 hours) in target scan mode • Pol. profile • Many more parameters: pol. decay in a fill, pol. vector in trans. plane, beam emittance etc. • Polarization for experiments (in collisions), after normalization to Hjet and correction for pol. profile

  4. Run9 results

  5. Systematic Errors

  6. Syst. Errors: HJet • Jet normalization, stat: 2.5% for 250 GeV and 1.0% for 100 GeV • That’s what existing data gave us • Jet normalization, syst (dilution): 2% • That’s what we’ve been using since Run4 (molecular contribution) • Jet normalization, syst (backgr): 2-3% • From the measurements of backgr. asymmetries • Run8: 1.3-2.4%; Run6: 1.3-1.9%

  7. pC: Time dependence in a fill 0.62 0.70 0.62 0.60 0.54 0.57 0.44 0.53 0.64 0.68 0.60 0.64 0.49 0.56 0.40 0.52 Time, hr Time, hr Pol. decay!

  8. pC: average over a fill Tpdecay – from pC TLdecay = 5 hr   Comparison of <P> with TLdecay = 5 hr and  (TLdecay = is equivalent to a weighted average) Only few fills showed syst. problems  assign additional syst. error for these fills

  9. pC in 2009: issues and strategy • Rate related systematics • Particularly at s=500 GeV • Failed to find a way to correct it (rate is defined by prompts which are already cut off by DAQ) • Strategy: • Two polarimeters in a ring are averaged • Fill-by-fill systematic uncertainties evaluated from the comparison between two polarimeters and between pC and HJet

  10. Fill dependence (pC vs HJet) 250 GeV No systematic effect seen on the HJet stat. error level

  11. Fill dependence (pC vs HJet) 100 GeV No systematic effect seen on the HJet stat. error level

  12. Fill dependence (Pol1 vs Pol2) 250 GeV RMS of the variation  12% fill-by-fill syst. uncertainty Not yet normalized to HJet

  13. Fill dependence (Pol1 vs Pol2) 100 GeV RMS of the variation  6% fill-by-fill syst. uncertainty Not yet normalized to HJet

  14. Pol. Profile (all) 250 GeV 100 GeV ~0.40 ~0.08

  15. Pol. Profile (good) 250 GeV 100 GeV ~0.40 ~0.08

  16. Pol. Profile: summary 250GeV: <R>=0.360.14; with fill-by-fill variation 0.36 100GeV: <R>=0.080.04; with fill-by-fill variation 0.08 <R>=0.360.14  (155)% correction from Hjet to experiments <R>=0.080.04  (42)% correction from Hjet to experiments

  17. Summary • http://www4.rcf.bnl.gov/~cnipol/pubdocs/Run09Offline/ • Global systematic uncertainties: • Blue, s=500 GeV: 8.3% • Yell, s=500 GeV: 12.1% • Blue, s=200 GeV: 4.7% • Yell, s=200 GeV: 4.7% Run5: 5.9% and 6.2% Run6: 4.7% and 4.8% Run8: 4.2% and 7.2%

  18. Path Forward

  19. Backup

  20. Sookhyun: Background raw asymmetries From MeanSigma

  21. pC: pol. Decay in a fill In a fill: fit to exp(-t/Tdecay) s=500 GeV 1/Tdecay <Tdecay> = 10-100 hours <Tdecay> = 10-100 hours (<Tdecay>=100 hr  1%/hr) • Run6: • <Tdecay> ~150 hours • Run8: • <Tdecay> ~400 hours • <Tdecay> ~100 hours Affected by rates!

  22. pC: pol. Decay in a fill In a fill: fit to exp(-t/Tdecay) s=200 GeV 1/Tdecay <Tdecay> = 50-200 hours <Tdecay> = 50-200 hours (<Tdecay>=100 hr  1%/hr) • Run6: • <Tdecay> ~150 hours • Run8: • <Tdecay> ~400 hours • <Tdecay> ~100 hours Affected by rates!

  23. pC: Time dependence in a fill s=500 GeV

  24. Time dependence (pC vs HJet), vs period s=500 GeV

  25. Time dependence (pC vs HJet), vs period s=200 GeV

  26. Pol1 vs Pol2 s=500 GeV s=200 GeV Blue Yell

  27. Pol. Profile: rate dependence s=500 GeV s=200 GeV

  28. Horizontal component s=500 GeV s=200 GeV ||<50 ||<50 ~50 ~5-100

  29. pC: Intensity Profile • Good profile: • Perfect gaussian • Low rate • Bad profile: • Non-gaussian • Low rate • Target positionig problem? • Bad profile: • Non-gaussian • High rate • Rate problem?

  30. I 2. Obtain R directly from the P(I) fit: P    pC: Polarization Profile R=0.290.07 Scan C target over the beam cross: pC Intensity 1. Directly measure I and P : I Polarization P Target Position Precise target positioning is NOT necessary

  31. Normalization for pC (Hjet/pC) Initial normalization from Run4 (s=200 GeV)

  32. AN pC pp

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