# Presentation: 791769

## AGS CNI PolarimeterFY03 Results

- Jeff Wood, UCLA

## Outline

- Overview of 2003 data
- Polarization history in AGS
- A at various beam energies
- Polarization during AGS ramp
- AGS-RHIC Comparison
- Finalizing data
- Background Studies
- Energy Calibration

## 2003 AGS Polarization vs. Day

-  Provided feedback  tune many machine parameters
-  Polarization generally increased throughout the run

- Pbeam

- 0.6

- 0.5

- 0.4

- 0.3

- 0.2

- 0.1

- 0.0

- day from March 1, 2003

**Notes:**
Mention P decrease at end of run

## CNI AN Calibration with E880

- For –t = 0.009 – 0.022 (GeV/c)2

- * Uncertainty
- from E880 AN
- not included

| G | date | E880 P* | CNI AN (%) |
| --- | --- | --- | --- |
| 7.5 | May 15 | 73.6 ± 0.29  | 5.87 ± 0.02 |
| 12.5 | May 17, 21 | 67.7 ± 0.9  | 3.05 ± 0.04 |
| 18.5 | May 28 | 64.6 ± 1.4  | 1.83 ± 0.04 |
| 24.5 | May 30 | 64.1 ± 2.1  | 1.43 ± 0.05 |
| 41.5 | May 27, 28 | 48.8 ± 1.9  | 1.06 ± 0.04 |

- AN at 46.5:  fit to E950 data (L. Trueman hep-ph/0305085)
- <AN> = 1.16%

**Notes:**
State L. Trueman’s number that was used at 46.5, A_N = 1.16%

## AN –t Dependence

- AN

- Carbon energy (keV)

- -t (Gev/c)2

- 3.5 GeV
- 6.5 GeV
- 9.7 GeV
- 12.8 GeV
- 21.7 GeV
- _24.3 GeV_

- Curve from
- Fit to E950

## Asymmetry during AGS Acceleration

- Asymmetry flips sign at every G = n

- ~1 ms
- bin width

- G

- Raw asymmetry = AN  Pbeam

- 25

- 30

- 35

- 40

- 45

- 0.015

- 0.01

- -0.015

- -0.005

- -0.01

- 0.005

- 0

- Ebeam
- (GeV)

- 12

- 14

- 16

- 18

- 20

- 22

- 24

**Notes:**
Define G = p anomalous magnetic moment, gamma = Lorentz factor
50 MeV/c momentum bins ~ 1ms time bin
Weak intrinsic resonance at 48 – nu_y

## Polarization during AGS Acceleration

-  Consistent with smooth polarization loss from 11 to 23 GeV
-  ~15% relative loss at strong intrinsic resonance 36 + 

- AN

- G

- G

- 38.5

- 0.6

- 0.4

- 0.2

- 0

- 25

- 30

- 35

- 40

- 45

- 36 + y

- Pbeam

- Model for G dependence of AN
-  Interpolate AN from measurements at
-    G = 18.5, 24.5, 41.5 and 46.5
-  AN constant for G = 38.5 – 46.5

- 12

- 14

- 16

- 18

- 20

- 22

- 24

- Ebeam

- 36 - y

- 48 - y
- no loss

## AGS - RHIC Comparison

-  AGS measurements occuring near RHIC fill
-  average RHIC injection measurements for each fill

- All polarimeters see drop in P at end of run

## Ratio PRHIC/PAGS

- Constant fit:

- Ratio = 0.936

- Ratio = 0.952

**Notes:**
Line drawn at 1

## Systematic Studies

- Background subtraction:
- Fit mass with
- G1 + G2 + a + b/x
- Try other functions
-     for background
- Use 1, 2 and 3 cuts
- Compare how
-     asymmetry changes

## Asymmetries w/ Background Fitting

- Mean difference After – Before
-      1:  1.2% shift       2:  1.7% shift       3:  2.5% shift

- Asymmetry
- with “banana”
- cut

- fit fuction used

-  cut

- raw asymmetry

- Before background subtraction
- After background subtraction

## Conclusions and Outlook

- FY03 AGS CNI Data
- P generally increased or stable during run
- AN (w/ –t dependence) studied at various beam energies
- AGS Ramp: no losses at G = 48 – 
- P loss < ~7% AGS to RHIC
- Systematic Studies
- Asymmetry stable with different cuts
- Background effect < 3% on asymmetry
- Energy calibration to be studied