Polarization Measurements of RHIC-pp RUN05

Using CNI pC-Polarimeter

Polarization Measurements of RHIC-pp RUN05

Using CNI pC-Polarimeter

Itaru Nakagawa (RIKEN/RBRC)Itaru Nakagawa (RIKEN/RBRC)On behalf of CNI Polarimeter GroupOn behalf of CNI Polarimeter GroupI.G.AlekseevI.G.AlekseevA A A.BravarA.BravarB B G.BunceG.BunceB B S.DhawanS.DhawanDD R.Gill R.GillBB H.Huang H.HuangB B W.HaeberliW.HaeberliE E G.Igo G.IgoFF O.Jinnouchi V.P.Kanavets O.Jinnouchi V.P.KanavetsAA K.Kurita K.KuritaHH A.Khodinov A.KhodinovJ J Z.Li Z.LiB B Y.Makdi Y.MakdisisiBB A.Nass A.NassBB W.Lozowski W.LozowskiII W.W.MacKay W.W.MacKayBB H.Okada H.OkadaGG S.Rescia S.ResciaBB T.Roser T.RoserBB N. N. SaitoSaitoG G H.Spinka H.SpinkaL L D.N.SviridaD.N.SviridaAA D.Underwood D.UnderwoodL L C.Witten C.WittenFF T.Wise T.WiseII J.Wood J.WoodF F A.A.ZelenskiZelenskiBB

RBRC ITEPRBRC ITEPAA BNL BNLBB ANL ANLCC Yale U Yale UDD Wisconsin U Wisconsin UEE UCLA UCLAFF Kyoto UKyoto UG G Rikkyo URikkyo UH H Indiana UIndiana UII StonyBrook U StonyBrook UJJ IUCF IUCFK K Argonne UArgonne ULL

Itaru Nakagawa (RIKEN/RBRC)Itaru Nakagawa (RIKEN/RBRC)On behalf of CNI Polarimeter GroupOn behalf of CNI Polarimeter GroupI.G.AlekseevI.G.AlekseevA A A.BravarA.BravarB B G.BunceG.BunceB B S.DhawanS.DhawanDD R.Gill R.GillBB H.Huang H.HuangB B W.HaeberliW.HaeberliE E G.Igo G.IgoFF O.Jinnouchi V.P.Kanavets O.Jinnouchi V.P.KanavetsAA K.Kurita K.KuritaHH A.Khodinov A.KhodinovJ J Z.Li Z.LiB B Y.Makdi Y.MakdisisiBB A.Nass A.NassBB W.Lozowski W.LozowskiII W.W.MacKay W.W.MacKayBB H.Okada H.OkadaGG S.Rescia S.ResciaBB T.Roser T.RoserBB N. N. SaitoSaitoG G H.Spinka H.SpinkaL L D.N.SviridaD.N.SviridaAA D.Underwood D.UnderwoodL L C.Witten C.WittenFF T.Wise T.WiseII J.Wood J.WoodF F A.A.ZelenskiZelenskiBB

RBRC ITEPRBRC ITEPAA BNL BNLBB ANL ANLCC Yale U Yale UDD Wisconsin U Wisconsin UEE UCLA UCLAFF Kyoto UKyoto UG G Rikkyo URikkyo UH H Indiana UIndiana UII StonyBrook U StonyBrook UJJ IUCF IUCFK K Argonne UArgonne ULL

Polarimetry: Impact on RHIC-SPINPolarimetry: Impact on RHIC-SPIN

€

ALL =1

Pbeam2

N↑↑ − N↑↓

N↑↑ + N↑↓

⎛

⎝ ⎜ ⎜

⎞

⎠ ⎟ ⎟ ⇒ ΔG

€

AN =1

Pbeam

N↑ − N↓

N↑ + N↓

⎛

⎝ ⎜ ⎜

⎞

⎠ ⎟ ⎟

Physics AsymmetriesSingle Spin Asymmetries

Double Spin Asymmetries

Polarization measurement by Elastic pp/pC

Polarized proton Recoil carbon

90º in Lab frame

Carbon target

↓↑LL NN or

↓↑RR NN or

↓↑or

€

Pbeam = −εN

ANpC

εN =NL − NR

NL + NR

Pbeam Required Accuracy ~5%

Pbeam Required Accuracy ~5%

€

rp p( p

r p ) /

r p C

pC Analyzing Power AN (100GeV)pC Analyzing Power AN (100GeV)

L. Truemanhep-ph/0305085

Recoil Carbon

€

Pbeam = −1

ANpC (t)

εN (t)

€

Pbeam = −1

ANpC (t)

εN (t)

Need to Measure Recoil Energy Need to Measure Recoil Energy

t-dependencet-dependence

RHIC PolarimetryRHIC Polarimetry

BRAHMS & PP2PP (p)

STAR (p)PHENIX (p)

AGS

LINAC BOOSTER

Pol. Proton Source500 A, 400 s

Spin RotatorsSolenoid Snake

Siberian Snakes

200 MeV Polarimeter

AGS pC CNI PolarimeterAC Dipole

RHIC pC Polarimeters

Absolute Polarimeter (H jet)

RHIC

Siberian Snakes

Cold Snake

Warm Snake

Characteristics of pC polarimeterCharacteristics of pC polarimeter

• Large Cross Section

• Solid target

• 20 sec./measurement for ~ 2% statistics.

• Immediate feedback to accelerator operation

• “Bunch by Bunch” beam polarization structure

• Polarization profile measurement

High Event Rate

pC Polarimeter SetuppC Polarimeter SetupUltra thin Carbon ribbon Target(3.5 g/cm2)

11

3344

55

66

22

Si strip detectorsSi strip detectors(TOF, E(TOF, ECC))

18cm18cm

10mm10mm

2mm pitch 12 strips2mm pitch 12 strips

72 strips in total72 strips in total

1

34

5

6

2

45 deg Physics45 deg Physics1

34

5

6

2

90 deg Physics90 deg Physics

Physics asymmetryPhysics asymmetry

1

34

5

6

2

1

34

5

6

2

Up-Down (Radial)Up-Down (Radial)Cross (Forbidden)Cross (Forbidden)

False asymmetry False asymmetry

Redundancy

Systematic/Consistency Check

Redundancy

Systematic/Consistency Check

Strip by Strip Consistency

2 Distribution of sin() fit– Well Distributed around 1– Evidence of Consistent Polarization Measureme

nts by individual strips

CarbonTarget

L

€

T =1

2M

L2

t 2

Energy CorrectionEnergy Correction

Tdeposit (keV ） )

Tim

e of

Flig

ht t m

eas[

ns]

€

T = Tdeposit + ΔT(Δx)(adc) (DeadLayer) (t0,x) Kinematic Fit (t0,x) Kinematic Fit

€

Tdeposit + ΔT(Δx) =1

2M

L2

tmeas + t0( )2

Energy Correction (Stability)

Stability Error9 ~ 11 g/cm2

Stability Error9 ~ 11 g/cm2

Online/Offline Polarization

Run5 Polarization Profile Run5 Polarization Profile

2mm2mm

Pol

ariz

atio

nC

ount

Rat

e[H

z]

Cou

nt R

ate[

Hz]

Pol

ariz

atio

n

Uncertainties & Summary

Energy Scale 3~4 %

Event Selection 1%

Polarization Profile

Normalization from Run4 8.5%

Total (Absolute) ~ 9%

€

} Relative

Run5 Smaller

Smaller

Backup Slides

Azimuthal Angle Distribution

Fill Number

an

gle

[deg

.]

Fill Number

an

gle

[deg

.]

= 0 deg.

Energy Correction

• Typical Thickness 〜 50 g/cm2

Kinetic Energy = ４００ keV

Correction

Observation

Ene

rgy

Loss

[ke

V]

Event Selection Dependence

2 vs 3 Cut Consistency Systematic Error

2

3

Event Selection Error

Event Selection Error ~ 1%( was 3% in Run3,4)

Event Selection Error ~ 1%( was 3% in Run3,4)

€

δ a /b( ) = (a /b) (δa /a)2 − (δb /b)2

Strip by Strip Consistency ~ sin() fit ~

11

3344

55

66

22

2mm pitch 12 strips2mm pitch 12 strips

Road Map to Finalize the Analysis

• Remaining Major Items – Continue QA (3 weeks)

• Suspicious bunch, strips

– Study Off-Centered Target Measurements(2 ~ 4weeks)

• Fill by Fill Analysis• Polarization Profile

– Normalization with Jet (4 weeks)

Energy Correction (Strip by Strip Consistency)

Strip Number （７２ Total ）

Ene

rgy

Cor

rect

ion(g

/cm

2 )

•All Detectors are made from same wafers Any inconsistency should be accounted as sys

Energy Correction (Strip by Strip Consistency)

Systematic Error Summary(1)

Blue Yellow

Energy Calibration --- ---

strip-by-strip consistency

3.5 (1) 4.5 (2)

Event Selection 3 3

Stability 9.0 11.1

Total 10.1 (9.1) 12.3 (11.3)Ene

rgy

Cor

rect

ion

[ug/cm2]

( ):Relative Error

€

Ekin

12C = Cα • (ADC) + Edead (Δx)

Contents

• Kinematics Reconstruction

source energy calibration– Deadlayer energy correction– Systematic error estimation(1)

• Polarization (1st Path Analysis Results)– Online/Offline– Event selection 2/3– Strip by strip consistency sin() fit– Systematic error estimation (2)