spin physics at rhic abhay deshpande riken bnl research center qcd 2002 indian institute of...

Spin Physics at RHIC

Abhay DeshpandeRIKEN BNL Research Center

QCD 2002Indian Institute of Technology, Kanpur

November 19, 2002 Spin Physcis at RHIC 2

OverviewOverviewNUCLEON SPIN• Present status and open questions

RHIC SPIN (Present: RECENT RESULTS)• Relativistic Heavy Ion Collider at BNL• Status of polarized proton Collider (Year 2001-2002) -- Expectation for Year 2002-2003• Polarized p-p physics at RHIC results FY02 -- Expectations FY03• Long term perspective for RHIC Spin (pp)

Electron Ion Collider at RHIC (Future)• Electron ring at RHIC• Physics goals of EIC (… mostly e-p… but also e-A)• Status & Plans


Parton Distributions

q

q

g

Nucleon

u u

d

averagehelicity quark)Qq(x 2,

differencehelicity quark )Qq(x 2,

fliphelicty )Qq(x 2,

(well known)

(moderately well known)

(unknown)

onDistributi Gluon)QxG 2,(

(moderately well known)

onPolarizati Gluon )QxG 2,((unknown)


Our knowledge of spin structure Our knowledge of spin structure functionfunction

F2

g1

Q2 (GeV2) Q2 (GeV2)10510 1021 10103


Nucleon Spin: Status & Open Nucleon Spin: Status & Open QuestionsQuestions

Proton Spin Puzzle remains unsolved!

constrained, need to measure G

SMC, B. Adeva et al. Phys. Rev. D 112002 (1999)

07.023.0)1,( 22

dxQx GeV

5.10.1

1

0

22 99.0)GeV 1,( dxQxgG

Gluon Spin Contribution:

Quark Spin Contribution:


Relativistic Heavy Ion ColliderRelativistic Heavy Ion Collider

this is testRHIC accelerates heavy ion beams upto and polarized proton

beams to 250 GeV

Two large detectors PHENIX and STAR

have extensive Spin Physics Programs

PHENIX

STAR

GeVA 100


RHIC Accelerator ComplexRHIC Accelerator Complex

BRAHMS & PP2PP (p)

STAR (p)

PHENIX (p)

AGS

LINACBOOSTER

Pol. Proton Source500 A, 300 s

GeVs

L

50050

onPolarizati%70

cms102 2132max

Spin Rotators

Partial Siberian Snake

Siberian Snakes

200 MeV Polarimeter AGS Internal PolarimeterRf Dipoles

RHIC pC Polarimeters

Absolute Polarimeter (H jet)

2 1011 Pol. Protons / Bunch = 20 mm mrad


RHIC PolarimetryRHIC Polarimetry

Beam’s View

Si #1

Si #2

Si #4Si #3

left right

down

up

Si #5

Si #6

Carbon filament target (5mg/cm2) in the RHIC beam

Measure recoil carbon ions at q~90º

100 keV < Ecarbon< 1 MeV

Wave-Form Digitizer +FPGA high counting rates (~0.5

MHz) scaler measurement A ~ 310-4 in ~1 minute.

Carbon

ADC values

Arr

ival

tim

e (n

s)


Siberian SnakesSiberian Snakes

STARPHENIX

AGSLINAC

RHIC

Effect of depolarizing resonances averaged out by rotating spin by large angles on each turn

4 helical dipoles S. snake2 snakes in each ring -- axes orthogonal to each other


Successful Operation of the Successful Operation of the SnakeSnake

• Injection with Spin Flipped: Asymmetry Flipped

• Adiabatically Snake on: Horizontal polarization

• Accelerate equivalent to 180o rotation: 180o rotated

Successful SingleSnake Operation !


Cheers!Cheers!


RHIC Luminosity FY02RHIC Luminosity FY02

PHENIX 150 nb-1

0

50

100

150

200

250

300

350

1 3 5 7 9 111315171921232527293133

Days into run (from 12/20/01)

STAR 300 nb-1

Machine Luminosity300 nb-1 /week

Peak 1.8x1030 cm-2s-1


Polarization Year 1Polarization Year 1

Yellow Ring Blue Ring


Why low polarization?Why low polarization?

10% 20% 30%

PAGS

PRHIC SourceImprovement

AGS power generator failure½ ramp up speed2x resonance effect

New AGSSNAKE2004-5

Ramp upSpead

Injection1st Year


Machine Performance Machine Performance ExpectationsExpectations

RUN #proton/bunch

[x109]#bunch Beta*

(m)

Emittance

(m)

Luminosity

1030 cm-2s-1

Pol.

(%)

2001-

2002

70 55 3 25 1.8 15-25

2002-2003

100 112 1 25 16 45-55

2005- ? 112 1 ? ? 70-80

Design 200 112 1 20 80 70


RHIC Spin Physics ProgramRHIC Spin Physics Program

• Spin Structure of Nucleon

– 1/2=(1/2)+G+Lq+Lg G: gluon polarization q: Anti-quark polarization

– New Structure Functions• h1: transversity

•NEW tool to study hadronic processes•W,Z @500GeV

•flavor sensitive studies on the structure functions

•cc/bb•Production mechanism

•Spin in fragmentation•Parity,CP violating interaction?

•Test of pQCD •Use asymmetries sensitive ONLY to the higher orders (AN at high PT etc.)

?QCD triumph? or

?beyond ?


G :onPolarizati Gluon

RHIC spin programRHIC spin program

Production

),( 0 XgqggALL

Heavy Flavors

),( XbbccggALL

Direct Photon

)( XgqALL

Jet Photon )( XJetgqALL

STA

R +

P

HEN

IX

Spin Transversed

d

d

d

u

u

u

u , , ,

W Production

)( lL lWduA

STAR +PHENIX

STAR +PHENIX

:)Qq(x,ty Transversi 2

:A sAsymmetrie Single N

BRAHMS, STAR, PHENIX, Local Polarimeter


PHENIX DetectorPHENIX DetectorEMCal Resolution

35.001.001.0 in

GeV/c 30-25 to up separation

Background/Signal

Muon IDPanels

CentralArms

North MuonArm

South MuonArm

Ring ImagingCerenkov

EM CalorimeterMuon Tracking

Chambers

Beam-BeamCounter

Multiplicity/VertexDetector

Time ExpansionChamber

Drift Chambers

Pad Chambers

Time of FlightPanels

cpT GeV/

GeV 200s


PHENIX Preliminary

Normalization error of 30% not shown.

On the way to On the way to G… G… 00 spectrum spectrum

PT spectrum over 8 order of magnitudeComparision with NLO pQCD calculation--CTEQ5M PDFs--Potter, Knielh, Kramer (PKK) fragmentation functions--Uncertainty shown: = pT/2, 2pT

Consistent with data within scaledependence

PHENIX 0 cross section (Preliminary)


PHENIX PreliminaryPHENIX Preliminary

µ+µ-e+e-

Br(J/l+l-) (total) = 226 36 (stat.) 79 (syst.) nb

(p+pJ/X) = 3.8 0.6 (stat.) 1.3 (syst.) µb

Total Cross section vs. the Total Cross section vs. the Color-Evaporation Model predictionColor-Evaporation Model prediction

• CEM Parameters are fixed by fitting low energy data• The result agrees with the CEM prediction at s=200GeV

Rapidity distribution compared Rapidity distribution compared with PHITHIA simulationwith PHITHIA simulation


STAR Performance

• Time Projection Chamber worked beautifully!

Au-Au Collision at STAR


Single spin asymmetries: L-RSingle spin asymmetries: L-R

Essential for proton spin orientation information at IPs

0 1 2 3 4 5Rapidity

STARFPD

0o CAL

BBC

PHE

NIX

MU

ON

PHE

NIX

CE

NT

RA

L

STA

R T

PC

pp2pp

E704 at Fermilab at s=20 GeV, pT=0.5-2.0 GeV/c: XF 0.2 0.4 0.6 0.8PT

Possible Origins: Transversity, Higher Twist,Fragmentation, kT, Orbital. Etc.


STAR Forward rapidity high xSTAR Forward rapidity high xFF 00 AANN

xF ~ E / 100 GeV

STAR FPD Preliminary DataAssuming AN(CNI)= 0.013pT=1.1 - 2.5 GeV/c

0.0

0.2

0.4

-0.20 0.2 0.4 0.6 0.8 1.0

AN

Systematic uncertainty + － 0.05

0 at s 200p p X GeV 0 at s 20p p X GeV Theory predictions

at pT = 1.5 GeV/c

Collins effectAnselmino, et al.PRD 60 (1999) 054027. Sivers effectAnselmino, et al.Phys. Lett. B442 (1998) 470.

Twist 3 effectQiu and Sterman,Phys. Rev. D59 (1998) 014004.

Y.KoikePaNic02


12 o’clock 12 o’clock PHENIX test setup PHENIX test setup

Hadron Cal Base

Pb

Scintillator

W+Fiber Cal

Post-shower

EM Cal Base

PbWO4

Charge Veto

Neutron Veto

0


AsymmetriesAsymmetriesEMCal ZDC


Asymmetries seen at RHIC so Asymmetries seen at RHIC so far…far…

0 1 2 3 4 5Rapidity

STARFPD

0o CAL

BBC

PHE

NIX

MU

ON

PHE

NIX

CE

NT

RA

L

STA

R T

PC

pp2pp

XF 0.2 0.4 0.6 0.8PT

0

+10 ~ +20%

Charged+1%

Neutron -10%

~0 %

0 ~0%


Upcoming Run FY03Upcoming Run FY03

3 pb-1 and 50%Expectation

G will be probed

STAR JET

PHENIX Charged


Search for new physics:Search for new physics:

• Anomalous parity violation in jet production – Contact Interaction (Scale )

• CDF>1.8 TeV• D0 >2.4 TeV• RHIC Spin Reach ~3.3 TeV

– New gauge boson Z’

P. Taxil & J-M. Virey, Phys. Rev. D(55) 2457 (1999)


RHIC Spin Schedule (PHENIX & STAR)

Year CM Energy Weeks Int. Lum. Remarks

FY2002 200 GeV 5 5 pb-1(1/15) Gluon pol. with pions

FY2003 200 GeV 8(3) 160 pb-1 Gluon pol. with jets500 GeV 2(0)? 90 pb-1 PV W production, u-quark

pol.500 GeV (1) Machine Studies, identify

Ws.FY2004 200 GeV 8 160 pb-1 Gluon pol. with g + jet/ TT

500 GeV 2 120 pb-1 First ubar,dbar pol. meas..

FY2005 500 GeV 8 480 pb-1 Gluon pol. with g+jet, g,jet+jet, heavy flavor, ubar, dbar pol.

200 GeV 2 48 pb-1 Gluon pol. with g, g+jet, heavy

flavor/TT

FY2006 500 GeV 5 300 pb-1 More statistics200 GeV 5 120 pb-1

FY2007 200 GeV 10 210 pb-1


Summary & OutlookSummary & Outlook

• RHIC spin program has begun: -- Polarized protons were injected and stored for extended

times in RHIC -- CNI polarimeters have measured non zero asymmetries

indicating polarization at 100 GeV proton beam energies -- Detectors are functional and will be 100% completed in

2004-5 -- A first round of single spin asymmetries have been measured• Next run 2002-3 promises to be the first one to

get us a first look at G -- First trials of 500 GeV run will be made and Ws produced

• A 5 year run plan exists for the RHIC spin physics -- to explore G, transversity, q & qbar is on the way


The Electron Ion ColliderThe Electron Ion Collider

A high energy, high intensity polarized electron beam facility at BNL to collide

with the existing RHIC heavy ion and polarized proton beam

would significantly enhance RHIC’s ability to

probe fundamental and universal aspects of QCD


Deep Inelastic ScatteringDeep Inelastic Scattering

•Observe scattered electron/muon & hadrons in current jets•Observe spectator or remnant jet


Why Collider in the Future?Why Collider in the Future?

• Past polarized DIS experiments: MOSTLY FIXED TARGET• Collider has distinct advantages --- Confirmed at HERA

• Better angular separation between scattered lepton & nuclear fragments

Better resolution of electromagnetic probe Recognition of rapidity gap events (recent diffractive physics)• Better measurement of nuclear fragments• Higher center of mass (CoM) energies reachable• Tricky integration of beam pipe – interaction region -- detector


EIC vs. DIS Facilities (I)EIC vs. DIS Facilities (I)

• New kinematic region

• Ee = 2-10 GeV

• Ep = 30 – 250 GeV

• Sqrt(s) = 20 – 100 GeV

• Kinematic reach of EIC x = 10-4 0.6 Q2 = 0 104 GeV

• High Luminosity L= (0.3 – 1.0) X 1033 cm-2 sec-1


EIC vs. Other DIS Facilities (II)EIC vs. Other DIS Facilities (II)

Variable beam energy

Variable hadron species

Hadron beam polarization

Large luminosity

TESLA-N


Scientific Frontiers Open to EICScientific Frontiers Open to EIC

• Nucleon Structure: polarized & unpolarized e-p/n scattering -- Role of quarks and gluons in the nucleon -- Spin structure: polarized quark & gluon distributions -- Unpolarized quark & gluon distributions -- Correlation between partons hard exclusive processes leading to

Generalized Parton Distributions (GPD’s)

• Nuclear structure: unpolarized e-A scattering -- Role of quarks and gluons in nuclei -- e-p vs. e-A physics in comparison

• Hadronization in nucleons and nuclei & effect of nuclear media

-- How do partons knocked out of nucleon in DIS evolve in to colorless hadrons?

• Partonic matter under extreme conditions -- e-A vs. e-p scattering; study as a function of A


Unpolarized DIS e-p at EICUnpolarized DIS e-p at EIC

• Large(r) kinematic region already covered at HERA but additional studies at EIC are possible & desirable

• Uniqueness of EIC: high luminosity, variable Sqrt(s), He3 beam, improved detector & interaction region

• Will enable precision physics: -- He3 beams neutron structure d/u as x0, dbar(x)-ubar(x)

-- precision measurement of S(Q2)

-- flavor separation (charm and strangeness) -- precision gluon distribution in x=0.001 to x=0.6 -- slopes in dF2/dlnQ2

-- precision photoproduction physics -- exclusive reaction measurements -- nuclear fragmentation region measurements


Polarized DIS at EICPolarized DIS at EIC• Spin structure functions g1 (p,n) at low x, high precision

-- g1(p-n): Bjorken Spin sum rule better than 1% accuracy• Polarized gluon distribution function G(x,Q2) -- at least three different experimental methods

• Precision measurement of S(Q2) from g1 scaling violations• Polarized structure function of the photon from photo-

production• Electroweak structure function g5 via W+/- production• Flavor separation of PDFs through semi-inclusive DIS• Deeply Virtual Compton Scattering (DVCS) Gerneralized

Parton Distributions (GPDs)• Transversity• Drell-Hern-Gerasimov spin sum rule test at high • Target/Current fragmentation studies• … etc….


Spin structure function gSpin structure function g1 1 at low at low xx

~5-7 days of data3 years of data

A. Deshpande & V. W. Hughes

Studies included statistical error & detector smearing to confirm that asymmetries are measurable. No present or future approved experiment will be able to make this measurement


Low x measurement of gLow x measurement of g11 of of NeutronNeutron

• With polarized He3 or deuteron

• ~ 2 weeks of data at EIC

• Compared with SMC(past) & possible HERA data

• If combined with g1 of proton results in Bjorken sum rule test of better than 1% within a couple of months of running (G.Igo & T. Sloan, AD & V. Hughes)

EIC 1 inv.fb

A. Deshpande & V. W. Hughes


Polarized Gluon Measurement at Polarized Gluon Measurement at EICEIC

• This is the hottest of the experimental measurements being pursued at various experimental facilities:

-- HERMES/DESY, COMPASS/CERN, RHIC-Spin/BNL & E159/E160 at SLAC

• Measurements at EIC will be complimentary with RHIC with a very different set of systematic uncertainties

- high Q2 assures no problems with interpretation of results

• Deep Inelastic Scattering kinematics at EIC -- Scaling violations (pQCD analysis at NLO) of g1

-- (2+1) jet production in photon-gluon-fusion process -- 2-high pT hadro production in PGF

• Photo-production (real photon) kinematics at EIC -- Single and di-jet production in PGF -- Open charm production in PGF


G from Scaling Violations of gG from Scaling Violations of g11

• World data (today) allows a NLO pQCD fit to the scaling violations in g1 resulting in the polarized gluon distribution and its first moment.

• SM collaboration, B. Adeva et al. PRD (1998) 112002 G = 1.0 +/- 1.0 (stat) +/- 0.4 (exp. Syst.) +/- 1.4 (theory)• Theory uncertainty dominated by the lack of knowledge of

the shape of the PDFs in unmeasured low x region where EIC data will play a crucial role.

• With approx. 1 week of EIC data, statistical and theoretical uncertainties on G will be reduced by a factor of 3

-- coupled to better low x knowledge of spin structure -- less dependence on factorization & re-normalization

scale uncertainty

A. Deshpande, V. W. Hughes & J. Lichtenstadt


Photon Gluon Fusion at EICPhoton Gluon Fusion at EIC

• “Direct” determination of G -- Di-Jet events -- High pT leading hadrons

• High Sqrt(s) at EIC -- no theoretical ambiguities• Both methods tried at HERA

for un-polarized gluon determination & both are successful!

-- NLO calculations exist -- H1 and ZEUS results -- Consistent with scaling

violation F2 results on G

Signal: PGF

BackgroundQCD Compton


Di-Jet events at EIC: Analysis at Di-Jet events at EIC: Analysis at NLONLO

• Stat. Accuracy for two luminosities

• Detector smearing effects considered

• NLO analysis

G. Radel, A. De Roeck, A. Deshpande, V. W. Hughes & J. Lichtenstadt

• Easy to differentiate different G scenarios: factor 3 improvements in ~2 weeks• If combined with scaling violations of g1: factors of 5 improvements in uncertainties observed in the same time.• Better than 3-5% uncertainty can be expected from EIC G program


Di-Jet at EIC vs. World Data for Di-Jet at EIC vs. World Data for G/G G/G

Good precisionClean measurement in x

range 0.01< x < 0.3Constrains shape of

G(x)Polarization in HERA

much more difficult than RHIC.

G. Radel & A. De Roeck

EIC Di-Jet DATA 2fb-1


Polarized PDFs of the PhotonsPolarized PDFs of the Photons

• Photo-production studies with single and di-jet

• Photon Gluon Fusion or Gluon Gluon Fusion (Photon resolves in to its partonic contents)

• Resolved photon asymmetries result in measurements of spin structure of the photon

• Asymmetries sensitive to gluon polarization as well… but we will consider the gluon polarization “a known” quantity!

Direct Photon Resolved Photon


Will measure the photon PDFs…Will measure the photon PDFs…• Stat. Accuracy

estimated for 1 fb-1 running (2 weeks at EIC)

• Single and double jet asymmetries

• ZEUS acceptance

• Will resolve photon’s partonic spin contents

Direct Photon Resolved Photon

M. Stratmann & W. Vogelsang


Parity Violating Structure Parity Violating Structure Function gFunction g55

• This is also a test

For EIC kinematics

• Experimental signature is a huge asymmetry in detector (neutrino)• Unique measurement• Unpolarized xF3 measurements at HERA in progress• Will access heavy quark distribution in polarized DIS


Measurement Accuracy PV gMeasurement Accuracy PV g55 at at EICEIC

Assumes:1. Input GS Pol.

PDfs2. xF3 measured by

then3. 4 fb-1 luminosity

Positrons & Electrons in EIC g5(+)

>> Issues for linac vs. ring design of EIC

J. Contreras & A. De Roeck


Drell Hern Gerasimov Spin Sum Drell Hern Gerasimov Spin Sum RuleRule

• DHG Sum rule:

• At EIC n range: GeV few TeV

• Although contribution from to the

this sum rule is small, the high n behavior is completely unknown and hence theoretically biased in any present measurements at:

Jefferson Lab., MAMI, BNL

S. Bass, A. De Roeck & A. Deshpande

• Inclusive Photo-production measurement

• Using electron tagger in RHIC ring Q2 ~ 10-6 10-2 GeV2

Sqrt(s) ~ 25 85 GeV


DVCS/Vector Meson ProductionDVCS/Vector Meson Production

• Hard Exclusive DIS process

• (default) but also vector mesons possible

• Remove a parton & put another back in!

Microsurgery of Baryons!

•Claim: Possible access to skewed or off forward PDFs? Polarized structure: Access to quark orbital angular momentum?

On going theoretical debate… experimental effort just beginning…


Strange Quark Distributions at Strange Quark Distributions at EICEIC

• After measuring u & d quark polarized distributions…. Turn to s quark (polarized & otherwise)

• Detector with good Particle ID: pion/kaon separation

• Upper Left: statistical errors for kaon related asymmetries shown with A1 inclusive

• Left: Accuracy of strange quark distribution function measurements possible with EIC and HERMES (2003-05) and some theoretical curves on expectations.

E. Kinney & U. Stoesslein


Highlights of e-A Physics at EICHighlights of e-A Physics at EIC

• Study of e-A physics in Collider mode for the first time• QCD in a different environment

• Clarify & reinforce physics studied so far in fixed target e-A & -A experiments including target fragmentation

QCD in: x > [1/(2mNRN) ] ~ 0.1 (high x)

QCD in: [1/(2mNRA)] < x < [1/(2mNRN)] ~ 0.1 (medium x)

• …. And extend in to a very low x region to explore: saturation effects or high density partonic matter also called

the Color Glass Condensate (CGC) QCD in: x < [1/(2mNRA)] ~ 0.01 (low x)


DIS in Nuclei is Different! DIS in Nuclei is Different!

Regions of:• Fermi smearing• EMC effect• Enhancement• Shadowing• Saturation?

Regions of shadowing and saturation mostly around Q2 ~1 GeV2

An e-A collision at EIC can be at significantly higher Q2

F2D/F2A

Low Q2!

E665, NMC, SLAC Experiments


Statistical Precision at EIC for e-Statistical Precision at EIC for e-AA

• High precision at EIC shown statistical errors for 1 pb-1

• Recall: EIC will deliver ~85 pb-1 per day

• NMC data F2(Sn/D)

• EIC’s Q2 range between 1 and 10 GeV2

• Will explore saturation region!

T. Sloan


A Case for EIC (I)A Case for EIC (I)

• Through its large luminosity, beam energy & beam species variability, the EIC will explore a new universal and fundamental aspects of QCD

• It is natural to assume that these measurements probe the initial conditions in the nuclei for parton distributions… as such this knowledge would be essential to fully understand the QGP which is being pursued at RHIC

• The e-A physics at RHIC will allow for the first time a large number of measurements which have never been performed beyond the fixed target regime… They will be at high energies where pQCD could be used reliably to understand the nuclear structure


A Case for EIC (II)A Case for EIC (II)

• The polarized e-N facility at the EIC will enable the polarized DIS studies of nucleons in a completely new x-Q2 that no other present or future facility will be able to access

• The variety of measurements at low Sqrt(s) will also include: -- inclusive physics in DIS as well as photoproduction regime -- semi-inclusive physics -- exclusive physics leading to DVCS, DES GPDs

• In addition a lot of spin measurements which would clearly study target and current fragmentation for the first time in polarized DIS will be possible with EIC


Moving Towards EIC….Moving Towards EIC….• September 2001: EIC grew out of joining of two communities: 1) polarized eRHIC (ep and eA at RHIC) BNL, UCLA, YALE and people from DESY & CERN 2) Electron Poliarized Ion Collider (EPIC) 3-5 GeV e X 30-50 GeV polarized light ions Colorado, IUCF, MIT/Bates, HERMES collaborators

• February 2002: White paper submitted to NSAC Long Range Planning Review Received enthusiastic support as a next R&D project (see: US/DoE Nuclear Report on the Web)

• Steering Committee: 7 members, one each from BNL, IUCF, LANL, LBL, MIT, UIUC, Yale + Contact person (AD)

• ~20 (~13 US + ~7 non-US) Institutes, ~100 physicists + ~40 accelerator physicists

• See for more details: EIC Web-page at “http://www.bnl.gov/eic”

• Subgroups: Accelerator WG, Physics WG, Detector WG


Present Collider LayoutPresent Collider Layout• Proposed by BINP & MIT/Bates• E-ring is ¼ of RHIC ring• Collisions in ONE interaction region• Collision energies 5-10 GeV• Injection linac 2-5 GeV• Lattice based on “superbend”

magnets• Self polarization using Sokolov

Ternov Effect: (14-16 min pol. Time)

• IP12, IP2 and IP4 are possible candidates for collision points

p

e2GeV (5GeV)

2-10 GeV

IP12

IP2

IP4

IP6

IP8

IP10

RHIC

OTHER : Ring with 6 IPS, Linac-Ring, Linac-Re-circulating ring


Interaction Region Design….Interaction Region Design….

B. Parker’s (BNL) ProposalBudker/MIT Proposal


A Detector for EICA Detector for EIC A 4 A 4 DetectorDetector

• Scattered electrons to measure kinematics of DIS• Scattered electrons at small (~zero degrees) to tag photo

production• Central hadronic final state for kinematics, jet measurements,

quark flavor tagging, fragmentation studies, particle ID• Central hard photon and particle/vector detection (DVCS)• ~Zero angle photon measurement to control radiative

corrections and in e-A physics to tag nuclear de-excitations

• Missing ET for neutrino final states (W decays)

• Forward tagging for 1) nuclear fragments, 2) diffractive physics

• EIC will provide: 1) Variable beam energies 2) different hadronic species, some of them polarization, 3) high luminosity


Detector Design (I)… others Detector Design (I)… others expectedexpected

J. Chwastowski & W. Krasny


A time line for EIC…A time line for EIC…

“Predictions are very difficult to make, especially when they are about the future” --- A very wise man….

• Proposal/CDR0 by 2004-2005• Expected formal approval 2005-6 Long Range Review• R&D money could start for hardware 2007• Construction of IR and Detector begin 2007-2008• 3-5 years for staged detector and IR construction

without interfering with the RHIC running• First collisions (2011)???

If any one knows how to do this earlier… -- I am listening.

spin physics at rhic abhay deshpande riken bnl research center qcd 2002 indian institute of...

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