K. Barish

Kenneth N. BarishSpin Praha 2007

Prague, Czech Rep.

July, 2007

The PHENIX Spin The PHENIX Spin Program Program Recent results & prospects

K. Barish

Proton Spin Structure at PHENIX

Prompt Photon LLA (gq X)

q1T

Measurement of

the transversity

and Sivers distribution

q,f q q

Flavor separation of

the quark and

anti-quark sea

and G

First moment of the

spin dependent

gluon disbribution

L lA (u d W )

T

,

A p p ( , ) X

Interference fragmentation:

:Transversity q

NSingle Asymmetries A Production LLA (gg,gq X) W Production

L lA (u d W )

Heavy Flavors LLA (gg cc,bb X)

TTDrell Yan A

K. Barish

Nucleon Spin Structure

Simple parton model:

1989 EMC (CERN):=0.120.090.14

Spin Crisis sdusdu

vv du 2

1

2

1

Determination of G and q-bar is the main goal of longitudinal spin program at RHIC

Gluons are polarized (G) Sea quarks are polarized:

Gqq 2

1

2

1

For complete descriptioninclude parton orbital angular momentum LZ: ZLGqq

2

1

2

1

K. Barish

•Valence distributions well determined

•Sea Distribution poorly constrained

•Gluon can be either positive, 0, negative!

Polarized PDFs from DIS

Asymmetry Analysis Collaboration M. Hirai, S. Kumano and N. Saito, PRD

(2004)

K. Barish

Utilizes strongly interacting probes

Probes gluon directly Higher s clean pQCD

interpretation Elegant way to explore guark and

anti-quark polarizations through W production

Polarized Gluon Distribution Measurements (G(x)): Use a variety of probes

Access to different gluon momentum fraction xDifferent probes – different systematics

Use different energies s Access to different gluon momentum fraction x

New experimental tool: polarized pp collider

K. Barish

Scattering processes in polarized p+p

qqg

g 2q

1f (x ) ˆˆ spp X f~ x

qg qˆ

Hard Scattering Process

2P2 2x P

g 2f x

q 1f x1P

1 1x P

zhqD

s

1ps

2ps

1 2LL LL

1 2

g(x ) q(x )ˆA a (qg q )

g(x ) q(x )

ˆ ˆ

K. Barish

)(

)2/(

0

0

HERMES

(hadron pairs)

COMPASS(hadron pairs)

E708(direct photon)

RHIC(direct photon)

CDF(direct photon)

pQCD partonic level asymmetries

NLO corrections are now known for all relevant reactions NLO corrections are now known for all relevant reactions

LOLLaHigh s and pT make the NLO pQCD analysis reliable

» dependence of the calculated cross section on represents an uncertainty in the theoretical predictions

M. S

trat

man

n an

d W

. Vog

elsa

ng

)(GeV/ cpT

K. Barish

Leading hadrons as jet tags

ˆ

Hard Scattering Process

2P2 2x P

j 2f x

i 1f x1P

1 1x P

zhqD

s

1ps

2ps

gggg

G

G

G

G

gqgq

G

G

q

q

qqqq

q

q

q

q

qg+gq

qq

gg

Tp

0

Fraction

's produced

Double longitudinal spin asymmetry ALL is sensitive to G

K. Barish

AGSLINACBOOSTER

Polarized Source

Spin RotatorsPartial Snake

Siberian Snakes

200 MeV Polarimeter

AGS Polarimeter

Rf Dipole

RHIC pC Polarimeters Absolute Polarimeter (H jet)

PHENIX

PHOBOS BRAHMS & PP2PP

STAR

Siberian Snakes

Helical Partial Snake

Strong Snake

Spin Flipper

2005 Complete!2005 Complete!

Approaching design

peak average design

L 2.5 1.2 6.0

P 67% 61% 70%

Luminosity in 1031cm-2s-1

RHIC can accelerate polarized protons!

K. Barish

Philosophy (initial Philosophy (initial

design):design): High rate capability & granularityHigh rate capability & granularity Good mass resolution & particle IDGood mass resolution & particle ID limited acceptancelimited acceptance

The PHENIX Detector for Spin Physics

detectionElectromagnetic Calorimeter:

Drift ChamberRing Imaging Cherenkov Counter

JMuon Id/Muon Tracker

Relative LuminosityBeam Beam Counter (BBC) Zero Degree Calorimeter (ZDC)

Local Polarimetry - ZDC

Filters for “rare” events

K. Barish

PHENIX polarized-proton runs

Year s [GeV] Recorded L Pol [%] FOM (P4L)

2003 (Run 3) 200 .35 pb-1 27 1.9 nb-1

2004 (Run 4) 200 .12 pb-1 40 3.1 nb-1

2005 (Run 5) 200 3.4 pb-1 49 200 nb-1

2006 (Run 6) 200 7.5 pb-1 62 1100 nb-1

2006 (Run 6) 62.4 .08 pb-1 ** 48 4.2 nb-1 **

Longitudinally Polarized Runs

Transversely Polarized Runs

Year s [GeV] Recorded L Pol [%] FOM (P2L)

2001 (Run 2) 200 .15 pb-1 15 3.4 nb-1

2005 (Run 5) 200 .16 pb-1 47 38 nb-1

2006 (Run 6) 200 2.7 pb-1 57 880 nb-1

2006 (Run 6) 62.4 .02 pb-1 ** 48 4.6 nb-1 **

** initial estimate

K. Barish

Total Raw Data VolumesWAN data transfer and data production at CC-J in RIKEN, Wako Japan

» 60MB/s sustained rate using grid60MB/s sustained rate using grid» 570 Tb transferred in Runs 5 & 6570 Tb transferred in Runs 5 & 6

K. Barish

prompt photon

cceX

bbeXJ/

GS95

xG

(x)

Robust measurement covering wide Robust measurement covering wide xxgg region through region through multiple channels:multiple channels:

I. Gluon PolarizationI. Gluon Polarization

ResultsResultsπ0 200GeV – Run 3, 4, 5,

6 (prelim) 64GeV – Run 6 (prelim)

πRun 5 (prelim)

Jet-like Run 4, 5(prelim)

Run 5(prelim)

J/Run 5, 6 (level2)

Photon Coming soon.gggg

G

G

G

G

gqgq

G

G

q

q

qqqq

q

q

q

q

gg QQ

G

G

G

G

gq g

G

G

q

q

See talk by P. Liebing

K. Barish

(N) Helicity dependent yields (R) Relative Luminosity

BBC vs ZDC

(P) PolarizationRHIC Polarimeter (at 12 o’clock)Local Polarimeters (SMD&ZDC)

Bunch spin configuration alternates every 106 ns Data for all bunch spin configurations are collected at the same

time Possibility for false asymmetries are greatly reduced

Measuring ALL

K. Barish

0 cross section at 200GeV

NLO pQCD calculations are consistent with cross-section measurements

g2 gq q2

2P2 2x P

1P

1 1x P

arXiv:0704.3599 [hep-ex]

K. Barish

0 ALL

PHENIX Preliminary Run6 (s=200 GeV)

Run3,4,5: PRL 93, 202002; PRD 73, 091102; hep-ex-0704.3599

pT(GeV)5 10

GRSV model:“G = 0”: G(Q2=1GeV2)=0.1“G = std”: G(Q2=1GeV2)=0.4

Statatistical uncertainties are on level to distinguish “std” and “0” scenarios

K. Barish

Relationship between pT and xgluon

Log10(xgluon)NLO pQCD: 0 pT=29 GeV/c

GRSV model: G(xgluon=0.020.3) ~ 0.6G(xgluon =01 )Note: the relationship between pT and xgluon is model dependent

Each pT bin corresponds to a wide range in xgluon, heavily overlapping with other pT bins

Data is not very sensitive to variation of G(xgluon) within measured range

Any quantitative analysis assumes some G(xgluon) shape

K. Barish

Sensitivity of 0 ALL to G

Scaling Errors not included

x

xG

(x)

GRSV std

present x-range

“std” scenario, G(Q2=1GeV2)=0.4, is excluded by data on >3 sigma level: 2(std)2

min>9Only exp. stat. uncertainties

are included (the effect of syst. uncertainties is expected to be small in the final results)

Theoretical uncertainties are not included

K. Barish

Global Analysis Results from various channels combined into single results for G(x) Correlations with other PDFs for each channel properly accounted Every single channel result is usually smeared over x global

analysis can do deconvolution (map of G vs x) based on various channel results

NLO pQCD framework can (should!) be used Global analysis framework already exist for pol. DIS data and being

developed to include RHIC pp data, by different groups

One of the attempts of global analysis by AAC Collaboration using PHENIX 0 Run5-Preliminary data

Now Run5-Final and Run6-Preliminary 0 and Run5-Preliminary jet data are available

-0.6-0.4-0.2

00.20.40.60.8

11.21.4

0.001 0.01 0.1 1

x

xg(x)

DIS (DIS only)

DIS + 0 (g > 0)

K. Barish

x

xG

(x)

GSC: G(xgluon= 01) = 1

GRSV-0: G(xgluon= 01) = 0

GRSV-std:G(xgluon= 01) = 0.4

GSC: G(xgluon= 01) = 1

GRSV-0: G(xgluon= 01) = 0

GRSV-std:G(xgluon= 01) = 0.4

ΔG(x) C from Gehrmann Stirling

present x-range

Much of the first momentΔG = ∫ΔG(x)dx might emerge from low x!

GSC-NLO: ΔG = ∫ΔG(x)dx = 1.0

GSC-NLO

GSC-NLO: ΔG = ∫0.02ΔG(x)dx ~ small00.3

Extending x-range is crucial

GSC: G(xgluon= 01) = 1 G(xgluon= 0.020.3) ~ 0

GRSV-0: G(xgluon= 01) = 0 G(xgluon= 0.020.3) ~ 0

GRSV-std:G(xgluon= 01) = 0.4 G(xgluon= 0.020.3) ~ 0.25

K. Barish

GSC-NLO: ΔG = ∫ΔG(x)dx = 1.0

Large uncertainties resultingfrom the functional form usedfor ΔG(x) in the QCD analysis!

GSC-NLO courtesy of Marco Stratmannand Werner Vogelsang

x

xG

(x)

present x-rangeNEED TO EXTEND

MEASUREMENTS TO

LOW x !!

PHENIX 0 ALL vs GSC-NLO

K. Barish

Extend x Range

present x-ranges = 200 GeV

Extend to lower x at s = 500 GeV

Extend to higher x at s = 62.4 GeV

To measure G, need as wide an x range as possible.Planned Upgrades will help (see later in this talk) By measuring at different center of mass energies, we can reach different x

ranges.We can extend our x coverage towards lower x at s = 500 GeV. Expected

to start in 2009.We can extend our x coverage towards higher x at s = 62.4 GeV. Run6

K. Barish

0 ALL @ s=62.4 GeV

GRSV: M. Gluck, E. Reya, M. Stratmann, and W. Vogelsang, Phys. Rev. D 53 (1996) 4775.

Short run with longitudinal polarized protonsALL

Grey band: systematic uncertainty due to Relative Luminosity

K. Barish

Comparison with 200 GeV

At fixed xT, 0 cross section is 2 orders of magnitude higher at 62.4 GeV than at 200 GeV

Converting to xT, we can get a better impression of the significance of the s=62.4 GeV data set, when compared with the Run5 final data set.

Run5 200GeV final 2.7pb-1 (49%)Run6 62.4GeV prelm. 0.04 pb-1 (48%)

K. Barish

Sign Ambiguity

Dominance of two gluon interaction at low pT present 0 ALL data cannot determine sign of G.

Solution:

» Higher pT higher FOM (P4L)

» Look to other probes:– Charged pions– Direct Photon

G2 Gq q2

Hard Scattering Process

2P2 2x P

1P

1 1x P

0

K. Barish

Charged pion ALL

Charged pions above 4.7 GeV identified with RICH. At higher pT, qg interactions become dominant and so

qg term is ALL becomes significant allowing access to the sign of G

Fraction of pion production

Tp ~ 5GeV

+ 0 -

+ 0 -u u u

LL LL LL

qg starts to dominate for and D D >DExpect sensitivity to sign of G, e.g., positive A A A

K. Barish

ALL of at s=200GeV

Run 5

K. Barish

“Golden Channel”» Gluon Compton Dominates» PHENIX well suited, but not easy & requires substantial L &

P

hep-ex/

0609031

Prompt production at s=200GeV

Run 3

1g

gL LT

pqL L

g(x )

g(xA (x ) a

)A (p )

2P 2 2x P

1P

1 1x P

qqgq

K. Barish

ALL of prompt at s=200GeV

isolated pi0 photon

signal

ALL

coming soon!

R E

1.0)5.0(

5.022

ERE

R

sum

Isolation cut toIsolation cut to reduce background

K. Barish

ALL of and J/at s=200GeV

» Complementary to 0 measurement

» fragmentation function not yet available.

g2 gq q22P 2 2x P

1P

1 1x P

gg QQ

G

G

G

G

K. Barish

π0/π/h

» 200GeV – run 2 (published), 5 (prelim)

» 64GeV – run 6 (prelim)

J/» Run 6 (level2)

Forward neutron – , xF

dependenceMPC Run6

» 64GeV (prelim)

II. Transverse Spin (AII. Transverse Spin (ANN))(Collins effect)

spin-dependentfragmentation

functions

(Sivers effect)transversely asymmetric

kt quark distributions

(Twist-3)quark gluon field

interference

0o CAL

MU

ON

CE

NT

RA

L

XF 0.2 0.4 0.6 0.8PT

BBC

MPC

Kinematical Coverage @ 200GeV

0 1 2 3 4 5Rapidity

q1Tq,f ,L

See talk by K. Oleg Eyser

K. Barish

AN of 0 and h for y~0 at s=200GeV

π0 (2001/02)

pt (GeV/c)

pt (GeV/c)

hep-ex/0507073(hep-ex/0507073)

AN is 0 within 1% interesting contrast with forward

PRL 95(2005)202001

|| < 0.35

Run 2Run 5

May provide information on gluon-Sivers effect gg and qg processes are dominant

— transversity effect is suppressed

K. Barish

AN of J/ at s=200GeV

Sensitive to gluon Sivers as produced through g-g fusion Charm theory prediction is available

» How does J/production affect prediction?

K. Barish

0 detection in forward direction» 3.1 < || < 3.65

South arm installed for Run 6 test.» Expect 200GeV

longitudinal and 62GeV longitudinal & transverse results

North installed for Run 7

Muon Piston Calorimeter (MPC)

MIP Peak

K. Barish

0 AN at large xF

3.0<<4.0

p+p0+X at s=62.4 GeV p+p0+X at s=62.4 GeV

Asymmetry seen in yellow beam (positive xF), but not in blue (negative xF)Large asymmetries at forward xF Valence quark effect?xF, pT, s, and dependence provide quantitative tests for theories

process contribution to 0, =3.3, s=200 GeV

PLB 603,173 (2004)

K. Barish

High luminosity and polarization » 200 & 500 GeV Running

Upgrades» Muon trigger upgrade» Nose-Cone Calorimeter Upgrade » Silicon barrel and forward upgrade

III. Future III. Future ProspectsProspects

K. Barish

Neutral pion projections

see Spin report to DOE http://spin.riken.bnl.gov/rsc/

Spin plan:Spin plan:» 65 pb-1 at √s=200GeV & 70% pol» 309 pb-1 at √s=500GeV & 70% pol

K. Barish

Prompt photon projections

Spin plan:Spin plan:» 65 pb-1 at √s=200GeV & 70% pol» 309 pb-1 at √s=500GeV & 70% pol

see Spin report to DOE http://spin.riken.bnl.gov/rsc/

K. Barish

Present vs with upgrades

Inclusive hadrons + photons forward heavy flavor + photons low x not pos. without upgrades parton kinematics

AN for inclusive hadronsAT in Interference-Fragmentation AT Collins FF in jets AN for back-to-back hadronsAN,T Ds, DY

not possible without upgrades (muon trigger, FVTX + NCC helpful)

Physics Goals

determine first moment ofthe spin dependent gluondistribution, ∫

0

1ΔG(x)dx.

measurement of trans-versity quark distributions.

Measurement of theSivers distributions, Lz

flavor separation of quarkand anti-quark spin distri-butions

q

)(

)(

xq

xq

)(xG

Physics Impact of PHENIX Upgrades

Sivers Effect

K. Barish

PHENIX Upgrade Components

pmuon

Muons from WsMuons from hadrons

R1

Muon fromhadron decays

Muon from W

R3

endcap

charm/beauty & jets: displaced vertex

Nosecone calorimeter W and quarkonium: improved -trigger rejection

-jet,e,,c

R2

Silicon barrel

K. Barish

NCCNCC

MP

C

MP

C

VTX & FVTX

-3 -2 -1 0 1 2 3 rapidity

cove

rage

2

EM

CA

LE

MC

AL

(i) 0 and prompt with combination of all electromagnetic calorimeters(ii) heavy flavor with precision vertex tracking with silicon detectors (iii) combine (i)&(ii) for -jet measurements

Future Acceptance for Hard Probes

K. Barish

Measuring the Gluon Spin Contribution Measuring the Gluon Spin Contribution

to the Proton Spin: to the Proton Spin: ΔΔG = G = ∫∫00

11ΔΔGG(x)dx(x)dx

1. Present measurements do not constrain functional form: They

determine ΔG = ∫0.02

0.3ΔG(x)dx

2. Longitudinal double spin asymmetries for open charm with the FVTX measure ΔG(x), [0.001,0.3]

3. Longitudinal double spin asymmetries for direct photons with the NCC measure ΔG(x), [0.001,0.3]. Jet-photon measurements using the NCC constrain the quark gluon kinematics and are sensitive to the functional form of ΔG(x).

First moment of ΔG(x)

prompt photonCentral arms

GS95

xG

(x)

K. Barish

Direct Photons (NCC) + Heavy Flavor (FVTX)

NCC direct photons

K. Barish

Nose Cone CalorimeterNCC Spin physics …NCC Spin physics …– Expands PHENIX’s kinematical coverage for jets, inclusive

neutral pions, electrons, and photons to forward rapidity – Detection of both hadron jet and final state photon

possible with the NCC and new silcon tracking detectors.– G with NCC at low-x through jet-G with NCC at low-x through jet-, , 00, e-, e-, open charm., open charm.– Isolation cut for W-bosons

log(xlog(xgg))

NCCNCC

centralcentral

fullfull

500 GeV 500 GeV Central arms prompt

10-110-210-310-410-5 110-1

1

10

102

103

104

NCC prompt NCC prompt

SLAC/ HERMES

SMC

xx

500 GeV 500 GeV QQ22

K. Barish

NCC prompt-NCC prompt-

GS-CGS-C

GS-BGS-B

GS-AGS-A

Central Arm prompt-Central Arm prompt-

GS-CGS-C

ppTT (GeV) (GeV)

Probing lower-x with the NCC

150 pb150 pb-1-1 @ 500 GeV@ 500 GeV

70% Pol70% Pol

150 pb150 pb-1-1 @ 500 GeV@ 500 GeV

70% Pol70% Pol

ppTT (GeV) (GeV)

AALLLL AALLLL

GS-C

present

NCC

K. Barish

Spin structure of the quark sea

How does the spin gluon field “feed down” to the quark sea?

Gluons are polarized (G) Sea quarks are polarized:

Gqq 2

1

2

1

x dLO extraction from SIDIS

x d Hermes: Phys.Rev.Lett 92 (2004) 012005

K. Barish

L

1 N NA

P N N

Experimentally clean measurement .Experimentally clean measurement .– AL is parity violating → no false

physics asymmetries.– Does not rely on knowledge of

fragmentation functions

Inclusive single spin muon Inclusive single spin muon asymmetries (from W’s) is a good asymmetries (from W’s) is a good probe of probe of q/q, q/q, q/q.q/q.– Complete theoretical treatment

from first principles by Nadolsky and Yuan using re-summation and NLO techniques [NuclPhysB 666(2003) 31].

– Does not suffer from scale uncertainties

Quark helicities fixed

Produced in pure V-Ap W productionW production» Produced in parity violating V-A process

— Chirality / helicity of quarks defined» Couples to weak charge

— Flavor almost fixed: flavor analysis possible

AL

pTRequires high luminosity 500GeV running + high rate muon trigger

Flavor separation of q and q sea

K. Barish

PHENIX vs HERMES

SIDIS:

large x-coverageuncertainties fromknowing fragmentationfunctions

W-physics:

limited x-coverageHigh Q2 theoretically cleanNo FF-info needed

Complimentary measurements

K. Barish

SummarySummaryRHIC is novel machine: provides collisions of polarized RHIC is novel machine: provides collisions of polarized protons at high energiesprotons at high energies» High enough s NLO pQCD is applicable

» Strongly interacting probes can be used to study nucleon structure

PHENIX is well suited to the study of spin physics with a wide PHENIX is well suited to the study of spin physics with a wide variety of probes.variety of probes.

» Inclusive neutral pion data for ALL has reached statistical significance to constrain ΔG in a limited x-range (~0.02-0.3).

– G is consistent with zero in the measured region, but theoretical uncertainties are high.

– Extending the x-coverage is crucial (higher/lower energy, upgrades)

– G is also being probed with charged pions, photons, etas, heavy flavor via muons and electrons, multi-particle “jets” …

» Anti-quark helicity distribution via W decay

PHENIX has an upgrade program that will give us the triggers PHENIX has an upgrade program that will give us the triggers and vertex information that we need for precise future and vertex information that we need for precise future measurements of measurements of G, G, q and new physics at higher luminosity q and new physics at higher luminosity and energyand energy

K. Barish

USA Abilene Christian University, Abilene, TX Brookhaven National Laboratory, Upton, NY University of California - Riverside, Riverside, CA University of Colorado, Boulder, CO Columbia University, Nevis Laboratories, Irvington, NY Florida Institute of Technology, FL Florida State University, Tallahassee, FL Georgia State University, Atlanta, GA University of Illinois Urbana Champaign, IL Iowa State University and Ames Laboratory, Ames, IA Los Alamos National Laboratory, Los Alamos, NM Lawrence Livermore National Laboratory, Livermore, CA University of Maryland, College Park, MD University of Massachusetts, Amherst, MA Muhlenberg College, Allentown, PA University of New Mexico, Albuquerque, NM New Mexico State University, Las Cruces, NM Dept. of Chemistry, Stony Brook Univ., Stony Brook, NY Dept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY Oak Ridge National Laboratory, Oak Ridge, TN University of Tennessee, Knoxville, TN Vanderbilt University, Nashville, TN

Brazil University of São Paulo, São PauloChina Academia Sinica, Taipei, Taiwan China Institute of Atomic Energy, Beijing Peking University, BeijingCzech Charles University, Prague, Republic Czech Technical University, Prague, Czech Republic Academy of Sciences of the Czech Republic, PragueFinland University of Jyvaskyla, JyvaskylaFrance LPC, University de Clermont-Ferrand, Clermont-Ferrand Dapnia, CEA Saclay, Gif-sur-Yvette IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, Orsay LLR, Ecòle Polytechnique, CNRS-IN2P3, Palaiseau SUBATECH, Ecòle des Mines at Nantes, NantesGermany University of Münster, MünsterHungary Central Research Institute for Physics (KFKI), Budapest Debrecen University, Debrecen Eötvös Loránd University (ELTE), Budapest India Banaras Hindu University, Banaras Bhabha Atomic Research Centre, BombayIsrael Weizmann Institute, RehovotJapan Center for Nuclear Study, University of Tokyo, Tokyo Hiroshima University, Higashi-Hiroshima KEK, Institute for High Energy Physics, Tsukuba Kyoto University, Kyoto Nagasaki Institute of Applied Science, Nagasaki RIKEN, Institute for Physical and Chemical Research, Wako RIKEN-BNL Research Center, Upton, NY Rikkyo University, Toshima, Tokyo Tokyo Institute of Technology, Tokyo University of Tsukuba, Tsukuba Waseda University, Tokyo S. Korea Cyclotron Application Laboratory, KAERI, Seoul Ewha Womans University, Seoul, Korea Kangnung National University, Kangnung Korea University, Seoul Myong Ji University, Yongin City System Electronics Laboratory, Seoul Nat. University, Seoul Yonsei University, SeoulRussia Institute of High Energy Physics, Protovino Joint Institute for Nuclear Research, Dubna Kurchatov Institute, Moscow PNPI, St. Petersburg Nuclear Physics Institute, St. Petersburg Lomonosoy Moscow State University, Moscow St. Petersburg State Technical University, St. PetersburgSweden Lund University, Lund

14 Countries; 68 Institutions; 550 Participants

K. Barish

Extra slides…

K. Barish

• Use Zero Degree Calorimeter (ZDC) to measure a L-R and U-D asymmetry in forward neutrons (Acceptance: ±2 mrad).

• When transversely polarized, we see clear asymmetry.

• When longitudinally polarized, there should be no asymmetry.

BLUE YELLOW

Raw

as

ymm

etry

Raw

as

ymm

etry

Use neutron asymmetry to study transversely polarized component.

BLUE YELLOW

Raw

as

ymm

etry

Raw

as

ymm

etry

Local Polarimety at PHENIX

K. Barish

Measured Asymmetry During Longitudinal Running

<PT/P>=10±2(%)

<PL/P> =99.48±0.12±0.02(%)

LR 2/NDF = 88.1/97p0 = -0.00323±0.00059

LR

UD 2/NDF = 82.5/97p0 = 0.00423±0.00057

XF>0 XF>0

XF<0 XF<0

2/NDF = 119.3/97p0 = 0.00056±0.00063

UD 2/NDF = 81.7/97p0 = -0.00026±0.00056

Fill NumberFill Number

<PT/P>=14±2(%)

<PL/P>=98.94±0.21±0.04(%)

Also confirmed in Run6 analysis

Measurement of remaining transverse component spin pattern is correct

(2005)

K. Barish

Relative Luminosity

Number of BBC triggered events (NBBC) used to calculate Relative Luminosity.

For estimate of Uncertainty, fit

for all bunches in a fill with

Year [GeV] R ALL

2005 * 200 1.0e-4 2.3e-4

2006 * 200 3.9e-4 5.4e-4

2006 * 62.4 1.3e-3 2.8e-3* Longitudinal

K. Barish

Possible contamination from soft physics

• By comparing 0 data with charged pion data, which has very good statistics at low pT, can estimate soft physics contribution

• Fitting an exponential to the low pT charged pion data (pT<1 GeV/c) gives an estimate on the soft physics contribution.

• Fit result: = 5.56±0.02 (GeV/c)−1

2/NDF = 6.2/3• From this, we see that for

pT>2 GeV, the soft physics component is down by more than a factor of 10.

exponential fit

PHENIX: hep-ex-0704.3599

For G constrain use 0 ALL data at pT>2 GeV/c

K. Barish

ALL of jet-like cluster at s=200GeV

Run 5

2P 2 2x P

1P

1 1x P

» “Jet” detection: tag one high energy photon and sum energy of nearby photons and charged particles

» Definition of pT cone: sum of pT measured by EMCal and tracker with R = (||2+||2)

» Real pT of jet is evaluated by tuned PYTHIA

K. Barish

Forward neutrons at s=200GeVAN

Without MinBias -6.6 ±0.6 %

With MinBias -8.3 ±0.4 %

neutronchargedparticles

Run 5

K. Barish

Large cross section is measured at √s=200GeV and consistent with xF.

K. Barish

Di-Hadron Azimuthal Correlations

Possible helicitydependence

Spin-correlated transverse momentum (orbital angular momentum) may contribute to jet kT.

Run 5

K. Barish

Take advantage of collaboration resources:» Run-5

– Cu+Cu 200 GeV at RCF May to August, 2006, 1.7G events in 4 months

– Cu+Cu 62.4 GeV at PHENIX 1008 farm Feb to March , 2006 0.6G events in 2 months

– Cu+Cu 22.5 GeV at PHENIX 1008 farm A few days to process 9M events

– p+p 200 GeV at CC-J in Japan p+p 200 GeV at CC-J in Japan Essentially completeEssentially complete All (270 TB) shipped via network All (270 TB) shipped via network

to CC-J.to CC-J.– Level-2 stream produced at ORNL

» Run-6 – p+p 62 GeV at PHENIX 1008 farmp+p 62 GeV at PHENIX 1008 farm

CompleteComplete– p+p 200 GeV at PHENIX 1008 p+p 200 GeV at PHENIX 1008

farmfarm Production for transverse Production for transverse

polarization underwaypolarization underway– p+p 200 GeV at PHENIX CC-Jp+p 200 GeV at PHENIX CC-J

Production for longitudinal Production for longitudinal polarization about to startpolarization about to start

– Level-2 produced at Vanderbilt» Simulation at Vanderbilt, LLNL, New Mexico

WAN data transfer and data production at CC-J (computing center in Japan, RIKEN, Wako)» 60MB/s sustained rate60MB/s sustained rate» 6 TB/day = 70 MB/sec max6 TB/day = 70 MB/sec max» Run5pp: 260 TB transferredRun5pp: 260 TB transferred» Run6pp: 310 TB transferredRun6pp: 310 TB transferred

– 200 GeV transverse/radial 100 TB– 200 GeV longitudinal 160 TB– 62.4 GeV 50

TB

Production for Production for allall PHENIX data-sets completed by start of Run-7 PHENIX data-sets completed by start of Run-7

PHENIX Data Production

K. Barish

Forward Neutron asymmetry reduced at 62 GeV, but still measurable.

xpos

xpos

xpos

xpos

Red : transverse data, Blue : longitudinal data

Blue Forward Blue Backward

Yellow BackwardYellow Forward

<PLR/AN>

BLUE 0.065 ± 0.143

YELLOW 0.132 ± 0.100

<PUD/AN>

BLUE -0.025 ± 0.119

YELLOW -0.020 ± 0.093

PLBLUE 100% – 2.3%

PLYELLOW 100% – 2.2%

62 GeV: Local Polarimetry

K. Barish

Calculate ALL(+BG) and ALL(BG) separately.

Get background ratio (wBG) from fit of all data.

Subtract ALL(BG) from ALL(+BG):

ALL(+BG) = w· ALL() + wBG · ALL(BG)

This method is also used for other probes with two particle decay mode:

• , J/

+BG region :±25 MeV around

peakBG region :

two 50 MeV regions around peak

Calculating 0 ALL

K. Barish

RHIC Forward Pion AN at 62.4 GeV

•Brahms Spectrometer at “2.3” and “3.0” setting <> = 3.44, comparable to PHENIX all eta•Qualitatively similar behavior to E704 data: pi0 is positive and between π+ andπ- , and roughly similar magnitude: AN(π+)/AN(π0) ~ 25-50%•Flavor dependence of identified pion asymmetries can help to distinguish between effects

•Kouvaris, Qiu, Vogelsang, Yuan, PRD74:114013, 2006•Twist-3 calculation for pions ( exactly at 3.3)•Derived from fits to E704 data at s=19.4 GeV and then extrapolated to 62.4 and 200 GeV•Only qualitative agreement at the moment. Must be very careful in comparisons (between experiments and theories) that kinematics are matched, since AN is a strong function of pT and xF

PHENIX and Brahms Preliminary

E704, 19.4 GeV, PLB 261, (1991) 201 Solid line: two-flavor (u, d) fitDashed line: valence + sea, anti-quark

K. Barish

Comparison to 0 at s = 200 GeV

STARSTAR

-- The apparent opposite trend in theηdependence between STAR and PHENIX may result from the difference in collsion energy and pT coverage-- Theoretic calculations for √s = 200 GeV appear to disagree with the experimental results