# Presentation: 831329

## Run6 CNI Analysis: Concluding Remarks and Summary of Systematic Uncertainties 

- A.Bazilevsky
- For RHIC CNI group
- RHIC Spin Collaboration Meeting
- November 30, 2007

## RHIC Polarimetry

- pC-Pol:
- Beam polarization
- PpCBeam  pCBeam(tpC)

- HJet-Pol:
- Jet polarization (diluted by molecular background)
- PJetTarget~0.92  JetTarget(tJet)
- (May be affected by other background)

- HJet-Pol:
- Beam polarization
- PJetBeam  JetBeam(tJet)
- (May be affected by other background)

## HJet Performance for 100 GeV

- Run6 Blue
- Run6 Yellow
- Run5 Blue
- Run5 Yellow

- Target asymmetry in Jet-Pol

- TRecoil (MeV)

- JetTarget

- Jet performance is very stable through the Years
- Background is small and its effect on JetTarget is small
-  Beam polarization is measured reliably by Jet-Pol

## pC/HJet

- Normalization changed by ~18% compared to Run4/5 normalization
*t*pC  range changed in **pCBeam(*t*pC)? – Should be investigated
- So far, pC-Pol can be used only as a relative polarimeter:                      re-normalization for each set-up (Year) is necessary
- Energy corrections within a Year are considered: 2.4% energy correction drift within a Year

- Only stat. errors included

- Blue

- Yellow

## HJet with Yellow beam

- Period #

- Target asymmetry

- Beam asymmetry

- Jet performance looks stable (target asymmetry is constant)

## pC/Jet: bad fills exlcuded

- Unfinished scans (plus 7654 and 7671)– Excluded
- (Only 1st yellow period is affected)

- Chi2/NDF in Yellow improved considerably:
- from 10.8/3 (CL=0.01) to 5.5/3 (CL=0.14)

- Open – “good”
- Solid - all

## pC/Jet: “Golden” vs others

**pC/Jet: “Golden” vs others**

- “Golden”: 	p0=1.1520.026  2/NDF=1.1/2 (CL=0.58)
-     Others: 	p0=1.1700.033  2/NDF=4.3/2 (CL=0.12)
- 	Consistent

- “Golden”: 	p0=1.1380.030  2/NDF=6.3/4 (CL=0.18)
-     Others: 	p0=1.2660.037  2/NDF=1.3/3 (CL=0.73)
- 	Different on ~3 level

- Open – Others
- Solid – “Golden”

- Others:
- Non-gaussian intensity profile
- (due to target positioning problems etc.)

- “Golden”:
- gaussian
- intensity profile

- Decision: use separate normalization for pC “Golden” fills and others.
- Price: stat. uncertainty for normalization increases by 1.5 (worst case)

## pC vs HJet

## HJet Performance for 31 GeV

- Blue: looks normal
- Background is as low as for 100 GeV
- Yellow: background is abnormally high
- Different background may affect differently **JetTarget and ** pCBeam

- Borrow blue pC normalization for yellow pC
- 100 GeV: pC blue and yellow normalization is the same within 11%
- (consistent for “golden”; shifted by ~(74)% for “others”)
- 31 GeV: energy correction changed differently in blue and yellow, compared to 100 GeV (by ~5mkg/cm2)  3% uncertainty

- The uncertainty for ANpC(yellow)= ANpC(blue) for 31 GeV beams is
- 11%  3% = 11.4%

- (See Kieran’s presentation from Nov. 15)

## P/P summary

******P/P summary**

- Global (correlated from fill to fill)
- Jet normalization, stat		 	2.3%, 2.4%  (5.9%, 5.9%)	3.1%, 2.8%
- Jet normalization (horiz profile)	        1.1%     (same)	0.5%, 2.2%
- *Jet normalization, syst (molecular)  	        2%         (2%) 	    2.0%
- *Jet normalization, syst (others)	1.3%, 1.5%  (1.9%,11.6%)   2.1%, 2.1%
- Pol. Profile (for experiments)	  	       2.0%       (2.6%) 	4.0%, 4.1%
- *Energy correction: 		       	       2.4%       (1.2%)	not included
- Global Total:				4.7%, 4.8%  (7.2%, 13.5%) 	5.9%, 6.2%

- Uncorrelated from fill to fill		Run6     		Run5
- 					100 GeV    (31 GeV)	100 GeV
- pC stat uncertainty in each fill:	 	   ~4%  	      (~5%) 	2-3%
- From horiz profile:	         	    	     included above   		1.5%, 4.0%
- From vert profile: 			    2.0%	      (2.6%) 	4.0%, 4.0%
- Energy correction: 		    	    1.2%	      (same)	1.2%, 1.6%

## Final Polarizations in Run6(for experiments)

**Final Polarizations in Run6****(for experiments)**

- Global syst. uncertainties:
- 		PB/PB= 	4.7% 	(7.2% for 31 GeV)
- 		PY/PY= 	4.8% 	(13.5% for 31 GeV)
- 		(PBPY/(PBPY)= 8.3% (19% for 31 GeV)

- 100 GeV

- 31 GeV

- 100 GeV

- 31 GeV

## Backups

## pC/Jet: Chi2/NDF for fits over fills

| Period | Golden | Others | All | Golden | Others | All |
| --- | --- | --- | --- | --- | --- | --- |
| 1 | 2/4 | 0/0 | 5/5 | 2/2 | 16/7 | 19/10 |
| 2 | 0/0 | 1/3 | 7/4 | 2/2 | 8/7 | 11/10 |
| 3 | 1/2 | 0/0 | 2/3 | 14/17 | - | 14/17 |
| 4 | 12/6 | 6/10 | 22/17 | - | 0.5/2 | 0.5/2 |
| 5 | 0.1/1 | - | 0.1/1 |  |  |  |
| All | 20/17 | 9/16 | 38/34 | 19/23 | 30/18 | 50/42 |

## pC vs Jet, yellow

| Period | All |  | “Golden” |  | “Others” |  |
| --- | --- | --- | --- | --- | --- | --- |
|  | Jet | pC | Jet | pC | Jet | pC |
| 1 | 0.4510.020 | 0.5510.010 | 0.4940.044 | 0.6030.018 | 0.4390.022 | 0.5380.011 |
| 2 | 0.5580.019 | 0.6150.006 | 0.5680.038 | 0.6180.013 | 0.5550.022 | 0.6140.007 |
| 3 | 0.5740.013 | 0.6640.008 | 0.5740.013 | 0.6640.008 | - | - |
| 4 | 0.5030.025 | 0.6350.016 | - | - | 0.5030.025 | 0.6350.016 |
| All | 0.5410.009 | 0.6300.005 | 0.5680.012 | 0.6560.007 | 0.5030.013 | 0.5950.006 |

## pC vs Jet, blue

| Period | All |  | “Golden” |  | “Others” |  |
| --- | --- | --- | --- | --- | --- | --- |
|  | Jet | pC | Jet | pC | Jet | pC |
| 1 | 0.5300.031 | 0.5860.011 | 0.5490.034 | 0.5820.012 | 0.4150.070 | 0.6090.027 |
| 2 | 0.5420.027 | 0.6310.013 | 0.6300.055 | 0.6060.031 | 0.5050.032 | 0.6430.013 |
| 3 | 0.5120.035 | 0.6370.018 | 0.5370.038 | 0.6520.019 | 0.2820.103 | 0.5090.056 |
| 4 | 0.5380.012 | 0.6530.007 | 0.5570.018 | 0.6520.010 | 0.5210.016 | 0.6550.009 |
| 5 | 0.5160.032 | 0.6240.019 | 0.5220.036 | 0.6240.019 | - | - |
| All | 0.5330.010 | 0.6410.005 | 0.5560.013 | 0.6330.007 | 0.5110.014 | 0.6490.007 |

## pC energy correction

- 100 GeV

- 100 GeV

- “Dead Layer” drifts in the range 4mkg/cm2 compared to middle point
-  2.4% for polarization correction
-  2.4% uncertainty on polarization due to energy correction

## Uncertainties due to polarization profile

- Lmax determination
- (the step size is finite, so we may miss maximum intensity point)
- Negligible (<0.2%)
- Target vibration
- <1%
- Gauss-ness of the profiles (L/Lmax range fit)
- <0.5%

- Total: <~1.1%

## Lmax determination

- Scan step size is 0.3-0.5mm  in worst case we can miss the Lmax(x) by X=0.5/2=0.25 mm
- For average case L~0.8mm R~0.1  P~0.5%
- (if we take X uniformly distributed between 0 and 0.25mm  P<0.2%)

- Uncertainty in P due to uncertainty Lmax is negligible

## Target vibration

- X=Acos(xt)

- A=1 mm

- A=2 mm

- A=0 mm

- Pol. prof

- P vs L/Lmax

- Lum. prof

- We don’t see indication in data that A > 2mm
- For A = 1mm (2mm), P = 0.6% (1%)

- Uncertainty due to target vibration is not sizable

## Gauss-ness of profiles (L/Lmax fit range)

- Variation in R (by ~0.01) may be due to non-gaussian shape of polarization profile
- This variation can be considered to be translated to global uncertainty (0.5% for jet normalization and 0.25% for experiments)
- On fill level: syst. uncertainties are absorbed by stat. uncertainty (2/NDF~1)

- All Run6 data for Yellow (~10000 points)

- cut

## R distribution

- R

- R

- Horizontal Profile:
- Variation in blue is 0 – 0.15
- Variation in yellow is 0.03 – 0.17
- Vertical Profile (assumptions):
- Variation in both blue and yellow is 0 – 0.17  (0 – 0.22 at 62 GeV )
**<R> = 0.085********0.085   (0.11********0.11 at 62 GeV)**

## Uncertainties due to pol. profile

- Global uncertainties:
- For Jet normalization (only horiz. profile matters): <1.1%
- 			In Run5: 0.5% for blue; 2.2% for yellow
- For experiments: 2.0% (vert. profile); horiz. is already included above
- 			In Run5: 4.0% for blue; 4.1% for yellow
- Fill uncertainties:
- Stat. uncertainties from fit (horiz)  2.0% (vert)

- Jet

- pC/Jet

- pC