Date post: | 03-Jan-2016 |
Category: |
Documents |
Upload: | jeremy-powers |
View: | 37 times |
Download: | 0 times |
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)