The Emerging QCD Frontier: The Electron Ion Collider · 27/11/2007 · Dominate structure of QCD vacuum (fluctuations in gluon fields) Responsible for > 98% of the visible mass in

The Emerging QCD Frontier:The Electron Ion ColliderPhysics Opportunities with e+A Collisions at the EIC

Thomas UllrichMIT

November 27, 2007

2

Theory of Strong Interactions: QCD

“Emergent” Phenomena not evident from Lagrangian Asymptotic Freedom & Color Confinement In large part due to non-perturbative structure of QCD vacuum

2


Action (~energy) density fluctuations of gluon-fields in QCD vacuum (2.4 ×2.4× 3.6 fm)(Derek Leinweber)


Gluons: mediator of the strong interactions Determine essential features of strong interactions Dominate structure of QCD vacuum (fluctuations in gluon fields) Responsible for > 98% of the visible mass in universe

2




Hard to “see” the glue in the low-energy world Gluon degrees of freedom “missing” in hadronic spectrum

but drive the structure of baryonic matter at low-x are crucial players at RHIC and LHC

2




Hard to “see” the glue in the low-energy world Gluon degrees of freedom “missing” in hadronic spectrum

but drive the structure of baryonic matter at low-x are crucial players at RHIC and LHC

⇒ How to study “glue” ?

3

How? With Deep Inelastic Scattering Experiments!Quantitative description of electron-proton scattering

e(k)

e(k´)

P(p)X(p´)

!"(q)

#e

Q2 = 4EeE!e sin2

!!!

e

2

"Q2 = !q2 = !(k ! k!)2

3


Measure of resolution power or “Virtuality”e(k)

e(k´)

P(p)X(p´)

!"(q)

#e

Q2 = 4EeE!e sin2

!!!

e

2

"

y =pq

pk= 1! E!

e

Eecos2

!!!

e

2

"

Q2 = !q2 = !(k ! k!)2

3


Measure of resolution power or “Virtuality”

Measure of inelasticity

e(k)

e(k´)

P(p)X(p´)

!"(q)

#e

Q2 = 4EeE!e sin2

!!!

e

2

"

y =pq

pk= 1! E!

e

Eecos2

!!!

e

2

"

x =Q2

2pq=

Q2

sy

Q2 = !q2 = !(k ! k!)2

3



Measure of momentum fraction of struck quark


e(k)

e(k´)

P(p)X(p´)

!"(q)

#e

Q2 = 4EeE!e sin2

!!!

e

2

"

y =pq

pk= 1! E!

e

Eecos2

!!!

e

2

"

x =Q2

2pq=

Q2

sy

Q2 = !q2 = !(k ! k!)2

3

How? With Deep Inelastic Scattering Experiments!

€

d2σ ep→eX

dxdQ2 =4παe.m.

2

xQ4 1− y +y 2

2

F2(x,Q

2) − y2

2FL (x,Q

2)

Quantitative description of electron-proton scattering


Measure of momentum fraction of struck quark


e(k)

e(k´)

P(p)X(p´)

!"(q)

#e

How can we measure color charge with DIS?

€

d2σ ep→eX

dxdQ2 =4παe.m.

2

xQ4 1− y +y 2

2

F2(x,Q

2) − y2

2FL (x,Q

2)

4

How can we measure color charge with DIS?

Scaling violation: dF2/dlnQ2 and linear DGLAP Evolution ⇒ G(x,Q2)

Gluons dominate low-x wave function

€

€

d2σ ep→eX

dxdQ2 =4παe.m.

2

xQ4 1− y +y 2

2

F2(x,Q

2) − y2

2FL (x,Q

2)

5

The Issue With Our Current Understanding

Established Model: Linear DGLAP evolution schemeWeird behavior of xG and FL from HERA at small x and Q2

Could signal saturation, higher twist effects, need for more/better data?

Unexpectedly large diffractive cross-section

5





more severe:

Linear Evolution has a built in high energy “catastrophe”xG rapid rise for decreasing x and violation of (Froissart) unitary bound⇒ must tame grow (saturate)

What’s the underlying dynamics?

5





more severe:

Linear Evolution has a built in high energy “catastrophe”xG rapid rise for decreasing x and violation of (Froissart) unitary bound⇒ must tame grow (saturate)

What’s the underlying dynamics? ⇒ Need new approach

6

Non-Linear QCD - Saturation

BFKL Evolution in x linear explosion of color field?

proton

N partons new partons emitted as energy increasescould be emitted off any of the N partons

Regimes of QCD Wave Function

6

Non-Linear QCD - Saturation

BFKL Evolution in x linear explosion of color field?

proton

N partons any 2 partons can recombine into one

Regimes of QCD Wave Function

New: BK/JIMWLK based models introduce non-linear effects ⇒ saturation

characterized by a scale Qs(x,A) arises naturally in the Color Glass

Condensate (CGC) framework

7

Scattering of electrons off nuclei: Probes interact over distances L ~ (2mN x)-1

For L > 2 RA ~ A1/3 probe cannot distinguishbetween nucleons in front or back of nucleon Probe interacts coherently with all nucleons

e+A: Studying Non-Linear Effects

7

Scattering of electrons off nuclei: Probes interact over distances L ~ (2mN x)-1

For L > 2 RA ~ A1/3 probe cannot distinguishbetween nucleons in front or back of nucleon Probe interacts coherently with all nucleons

e+A: Studying Non-Linear Effects

Nuclear “Oomph” FactorPocket Formula:

Enhancement of QS with A ⇒ non-linear QCD regime reached at significantly lower energy in A than in proton

!QA

s

"2 ! cQ20

#A

x

$1/3

8

Nuclear “Oomph” Factor

More sophisticated analyses ⇒ more detailed picture even exceeding the Oomph from the pocket formula (e.g. Kowalski, Lappi and Venugopalan, arXiv:0705.3047; Armesto et al., PRL 94:022002; Kowalski, Teaney, PRD 68:114005)

1/x

Q 2 (

Ge

V2)

1

0.1

10

10 2

10 3

10 4

10 5

10 6

Au (c

entra

l)

Q2s,g Ca (c

entra

l)

proto

ns

Kowalski and Teaney

Phys.Rev.D68:114005,2003

4

Figure 3. Summary of measurements of !s(Q2). Results which are based on fits of !s(MZ0) to datain ranges of Q, assuming the QCD running of !s, are not shown here but are included in the overallsummary of !s(MZ0), see Figure 4 and Table 1.

agreement with the QCD prediction.Therefore it is appropriate to extrapolate all

results of !s(Q) to a common value of energy,which is usually the rest energy of the Z0 boson,MZ0 . As described in [1], the QCD evolution of !s

with energy, using the full 4-loop expression [29]with 3-loop matching [30] at the pole masses ofthe charm- and the bottom-quark, Mc = 1.7 GeVand Mb = 4.7 GeV , is applied to all results of!s(Q) which were obtained at energy scales Q !=MZ0 .

The corresponding values of !s(MZ0) are tab-ulated in the 4th column of Table 1; column 5and 6 indicate the contributions of the experi-

mental and the theoretical unceratinties to theoverall errors assigned to !s(MZ0). All values of!s(MZ0) are graphically displayed in Figure 4.Within their individual uncertainties, there isperfect agreement between all results. This jus-tifies to evaluate an overall world average value,!s(MZ0). As discussed e.g. in [1], however, thecombination of all these results to an overall aver-age, and even more so for the overall uncertaintyto be assigned to this average, is not trivial dueto the supposedly large but unknown correlationsbetween invidual results, especially through com-mon prejudices and biases within the theoreticalcalculations.

8

Nuclear “Oomph” Factor

More sophisticated analyses ⇒ more detailed picture even exceeding the Oomph from the pocket formula (e.g. Kowalski, Lappi and Venugopalan, arXiv:0705.3047; Armesto et al., PRL 94:022002; Kowalski, Teaney, PRD 68:114005)

1/x

Q 2 (

Ge

V2)

1

0.1

10

10 2

10 3

10 4

10 5

10 6

Au (c

entra

l)

Q2s,g

!s(Q2)

!s(Q2s)

9

Universality & Geometric ScalingCrucial consequence of non-linear evolution towards saturation: Physics invariant along trajectories

parallel to saturation regime (lines of constant gluon occupancy)

Scale with Q2/Q2s(x) instead of x and

Q2 separately

9

Universality & Geometric ScalingCrucial consequence of non-linear evolution towards saturation: Physics invariant along trajectories

parallel to saturation regime (lines of constant gluon occupancy)

Scale with Q2/Q2s(x) instead of x and

Q2 separately

⇐ Geometric Scaling Consequence of saturation which

manifests itself up to kT > Qs

x < 0.01

e+p

10

Qs - A Scale that Binds them All ?

Freund et al., hep-ph/0210139

Nuclear shadowing: Geometrical scaling

proton × 5

nuclei

10

Qs - A Scale that Binds them All ?

Freund et al., hep-ph/0210139

Nuclear shadowing: Geometrical scaling

Are hadrons and nuclei wave function universal at low-x ?

proton × 5

nuclei

11

A Truly Universal Regime ?

Radical View: Nuclei and all hadrons have a component of their wave function

with the same behavior This is a conjecture! Needs to be tested

A.H. Mueller, hep-ph/0301109

Small x QCD evolution predicts: QS approaches universal

behavior for all hadrons and nuclei

⇒ Not only functional form f(Qs) universal but even Qs becomes the same

?

ZEUS BPC 1995

ZEUS SVTX 1995

H1 SVTX 1995

HERA 1994

HERA 1993

NMC

BCDMS

E665

SLAC

CCFR

10-1

1

10

102

103

104

10-6

10-5

10-4

10-3

10-2

10-1

1

x

Q2

VeG(

2)

12

eA Landscape and A New Electron Ion ColliderWell mapped in e+p

12


Not so for ℓ+A (νA)many of those with small A and very low statistics

NMC

BCDMS

E665

SLAC

CCFR

10-1

1

10

102

103

104

10-6

10-5

10-4

10-3

10-2

10-1

1

x

Q2

VeG(

2)

12


Electron Ion Collider (EIC):L(EIC) > 100 × L(HERA)

Electron Ion Collider (EIC):Ee = 10 GeV (20 GeV)EA = 100 GeV√seN = 63 GeV (90 GeV)High LeAu ~ 6·1030 cm-2 s-1


NMC

BCDMS

E665

SLAC

CCFR

1=y

10-1

1

10

102

103

104

10-6

10-5

10-4

10-3

10-2

10-1

1

x

Q2

VeG(

2)

20 GeV + 100 GeV/n

10 GeV +100 GeV/n

9 GeV + 90 GeV/n

EIC e+Au

12





1=y

10-1

1

10

102

103

104

10-6

10-5

10-4

10-3

10-2

10-1

1

x

Q2

VeG(

2)

20 GeV + 100 GeV/n

10 GeV +100 GeV/n

9 GeV + 90 GeV/n

EIC e+Au

Q 2s proton

Q 2s Ca (central)

Q 2s Au (central)

12


Terra incognita: small-x, Q ≈ Qs

high-x, large Q2




1=y

10-1

1

10

102

103

104

10-6

10-5

10-4

10-3

10-2

10-1

1

x

Q2

VeG(

2)

20 GeV + 100 GeV/n

10 GeV +100 GeV/n

9 GeV + 90 GeV/n

EIC e+Au

Q 2s proton

Q 2s Ca (central)

Q 2s Au (central)

PHENIX

STAR

e-cooling (RHIC

II)

Four e-beam passes

Main ERL (2 GeV per pass)

eRHIC(Linac-Ring)

Electron Ion Collider ConceptseRHIC (BNL): Add Energy Recovery Linac to RHICEe = 10 (20) GeVEA = 100 GeV (up to U)√seN = 63 (90) GeVLeAu (peak)/n ~ 2.9·1033 cm-2 s-1

TPC(2007$) ≈ $700 M

PHENIX

STAR

e-cooling (RHIC

II)

Four e-beam passes

Main ERL (2 GeV per pass)

Electron Cooling

Snake

Snake

IR

IReRHIC(Linac-Ring)

ELIC

13

Electron Ion Collider ConceptseRHIC (BNL): Add Energy Recovery Linac to RHICEe = 10 (20) GeVEA = 100 GeV (up to U)√seN = 63 (90) GeVLeAu (peak)/n ~ 2.9·1033 cm-2 s-1

TPC(2007$) ≈ $700 M

ELIC (JLAB): Add hadron beam facility to existing electron facility CEBAFEe = 9 GeVEA = 90 GeV (up to Au)√seN = 57 GeVLeAu (peak)/n ~ 1.6·1035 cm-2 s-1

Both allow for polarized e+p collisions !

EIC Covers Relevant Kinematic Region

10-510-4

10-310-2

1

10

0.1

!2QCD

Q2 (

Ge

V2)

200 120 40

A x

Pro

ton

Calc

ium

Gold

Parton Gas

Color Glass Condensate

Confinement Regime

EIC

Coverage

15

Understanding Glue in Matter ...... involves understanding its key properties which in turn define the required measurements:

What is the momentum distribution of the gluons in matter? What is the space-time distributions of gluons in matter? How do fast probes interact with the gluonic medium? Do strong gluon fields effect the role of color neutral

excitations (Pomerons)?

15


What system to use?



15


What system to use?1. e+p works, but more accessible by using e+A (Oomph Factor)



15


What system to use?1. e+p works, but more accessible by using e+A (Oomph Factor)2. have analogs in e+p, but have never been measured in e+A



15


What system to use?1. e+p works, but more accessible by using e+A (Oomph Factor)2. have analogs in e+p, but have never been measured in e+A 3. have no analog in e+p



15


What is the momentum distribution of the gluons in matter?

What is the space-time distributions of gluons in matter? How do fast probes interact with the gluonic medium? Do strong gluon fields effect the role of color neutral


‣ Extract from scaling violation in F2: δF2/δlnQ2

‣ FL ~ αs G(x,Q2) (BTW: requires √s scan)‣ 2+1 jet rates (needs modeling of hadronization)‣ inelastic vector meson production (e.g. J/ψ)‣ diffractive vector meson production ~ [G(x,Q2)]2

16

F2 : Sea (Anti)Quarks Generated by Glue at Low x

F2 will be one of the first measurements at EIC

nDS, EKS, FGS:pQCD based models with different amounts of shadowing

Syst. studies of F2(A, x, Q2):⇒ G(x,Q2) with precision⇒ distinguish between models

€

d2σ ep→eX

dxdQ2 =4πα 2

xQ4 1− y +y 2

2

F2(x,Q

2) − y2

2FL (x,Q

2)

17

FL at EIC: Measuring the Glue Directly

FL requires √s scanQ2/xs = y

Here: ∫Ldt = 5/A fb-1 (10+100) GeV = 5/A fb-1 (10+50) GeV = 2/A fb-1 (5+50) GeV

statistical error only

€

d2σ ep→eX

dxdQ2 =4πα 2

xQ4 1− y +y 2

2

F2(x,Q

2) − y2

2FL (x,Q

2)

nDS and EKS are "standard" shadowing parameterizations that are evolved with DGLAP

18

FL at EIC: Integrated over Q2

Here: ∫Ldt = 4/A fb-1 (10+100) GeV = 4/A fb-1 (10+50) GeV = 2/A fb-1 (5+50) GeV

statistical error only

Syst. studies of FL(A,x,Q2):⇒ G(x,Q2) with great precision⇒ distinguish between models

HKM and FGS are "standard" shadowing parameterizations that are evolved with DGLAP

19

How EIC will Address the Important Questions

What is the space-time distributions of gluons in matter? How do fast probes interact with the gluonic medium? Do strong gluon fields effect the role of color neutral



19


What is the space-time distributions of gluons in matter?

How do fast probes interact with the gluonic medium? Do strong gluon fields effect the role of color neutral


‣ Various techniques & methods:‣ Exclusive final states (e.g. vector meson production ρ, J/ψ)

‣ color transparency ⇔ color opacity

‣ Deep Virtual Compton Scattering (DVCS) γ*A → γA‣ Integrated DVCS cross-section: σDVCS ~ A4/3

‣ Measurement of structure functions for various mass numbers A (shadowing, EMC effect) and its impact parameter dependence


20

Vector Meson Production

HERA: Survival prob. of vector mesons (q q pair) as fct. of b extracted from elastic vector meson production (Munier curve: ρ0, Rogers: J/ψ)

Strong gluon fields in center of p at HERA (Qs ~ 0.5 GeV2)?

Surv

ival

Pro

babi

lity color opacity color transparency

“color dipole” picture

Note: b profile of nuclei more uniform and Qs ~ 2 GeV2

21


How do fast probes interact with the gluonic medium? Do strong gluon fields effect the role of color neutral


What is the momentum distribution of the gluons in matter? What is the space-time distributions of gluons in matter?

21


How do fast probes interact with the gluonic medium?

Do strong gluon fields effect the role of color neutral excitations (Pomerons)?

‣ Hadronization, Fragmentation‣ Energy loss (charm!)

What is the momentum distribution of the gluons in matter? What is the space-time distributions of gluons in matter?

22

Hadronization and Energy LossnDIS: Suppression of high-pT hadrons analogous but weaker than at RHIC Clean measurement in ‘cold’ nuclear matter

Fundamental question: When do colored partons get neutralized?

Parton energy loss vs. (pre)hadron absorption

zh = Eh/νEnergy transfer in lab rest frameEIC: 10 < ν < 1600 GeV HERMES: 2-25 GeVEIC: can measure heavy flavor energy loss

23

Connection to p+A Physics

e+A and p+A provide excellent information on properties of gluons in the nuclear wave functions

Both are complementary and offer the opportunity to perform stringent checks of factorization/universality ⇒

Issues: p+A lacks the direct access to x, Q2

F. Schilling, hex-ex/0209001

Breakdown of factorization (e+p HERA versus p+p Tevatron) seen for diffractive final states.

24

Charm at EIC

EIC: allows multi-differential measurements of heavy flavor covers and extend energy range of SLAC, EMC, HERA, and JLAB allowing study of wide range of formation lengths

Based on H

VQ

DIS m

odel, J. Smith

25



What is the momentum distribution of the gluons in matter? What is the space-time distributions of gluons in matter? How do fast probes interact with the gluonic medium?

25



d!

dt

!!!!t=0

("!A! V A) " #2s[GA(x,Q2)]2

‣ diffractive cross-section σdiff/σtot

‣ diffractive structure functions‣ shadowing == multiple diffractive scattering ?‣ diffractive vector meson production - very

sensitive to G(x,Q2)

What is the momentum distribution of the gluons in matter? What is the space-time distributions of gluons in matter? How do fast probes interact with the gluonic medium?

26

Diffractive Physics in e+A

‘Standard DIS event’

Activity in proton direction

26

Diffractive Physics in e+A

Diffractive event

Activity in proton direction

HERA/ep: 15% of all events are hard diffractive Diffractive cross-section σdiff/σtot in e+A ?

Predictions: ~25-40%? Look inside the “Pomeron”

Diffractive structure functions Diffractive vector meson production ~ [G(x,Q2)]2

?

d4!eA!eAX

dxdQ2d"dt=

4#$2e.m

"2Q4

!"1! y +

y2

2

#FD

2 ! y2

2FD

L

$

27

Diffractive Structure Function F2D at EIC

⇒ Distinguish between linear evolution and saturation models

⇒ Insight into the nature of pomeron ⇒ Search for exotic objects (Odderon)

xIP = momentum fraction of the pomeron w.r.t the hadron

Curves: Kugeratski, Goncalves, Navarra, EPJ C46, 413

= x/xIP

28

Thermalization: At RHIC system thermalizes (locally)

fast (τ0 ~ 0.6 fm/c) We don’t know why and how? Initial

conditions?

Connection to RHIC & LHC Physics

28



conditions?

Connection to RHIC & LHC PhysicsFF modification (parton energy loss)

Jet Quenching: Refererence: E-loss in cold matter d+A alone won’t do

• ⇒ need more precise handles no data on charm from HERMES

28



conditions?


Forward Region: Suppression at forward rapidities

• Color Glass Condensate ?• Gluon Distributions ?



28



conditions?


Forward Region: Suppression at forward rapidities

• Color Glass Condensate ?• Gluon Distributions ?



Accardi et al., hep-ph/0308248,CERN-2004-009-A

Even more crucial at LHC:Ratios of gluon distribution functions for Pb versus x from different models at Q2 = 5 GeV2:

?

29

Many New Questions w/o Answers …

From RHIC: Observe “E-loss” of direct photons

• Are we seeing the EMC effect?

29

Many New Questions w/o Answers …

From RHIC: Observe “E-loss” of direct photons

• Are we seeing the EMC effect?Many (all?) of these questions cannot be answeredby studying A+A or p+A alone.

EIC provides new level of precision:• Handle on x, Q2

• Means to study effects exclusively• RHIC is dominated by glue ⇒ Need to know G(x,Q2)

In short we need ep but especially eA ⇒ EIC

30€

dg1d log(Q2)

∝−Δg(x,Q2)

ΔG = Δg(x,Q2)dxx= 0

x=1

∫

Superb sensitivity to Δg at small x!

Spin Physics at the EIC - The Quest for ΔG

Spin Structure of the Proton½ = ½ ΔΣ + ΔG + Lq + Lg

quark contribution ΔΣ ≈ 0.3 gluon contribution ΔG ≈ 1 ± 1 ?

ΔG: a “quotable” property of the proton (like mass, charge)

Measure through scaling violation:

E155

E143

SMC

HERMES

0.01

0.1

1

10

100 101 102 103 104

Q2(GeV2)

gp 1(x

,Q2)

+ C

(x)

x = 0.0007

x = 0.0025

x = 0.0063

x = 0.0141

x = 0.0245

x = 0.0346

x = 0.0490

x = 0.0775

x = 0.122

x = 0.173

x = 0.245

x = 0.346

x = 0.490

x = 0.735

EIC

Coverage

x

2.5 < Q2 < 7.5 GeV

2

1

0

10-3 10-2 10-1-1

31

Experimental Aspects at the EIC

31


Concepts: Focus on the rear/forward acceptance and thus on low-x / high-x physics

• compact system of tracking and central electromagnetic calorimetry inside a magnetic dipole field and calorimetric end-walls outside

I. Abt, A. Caldwell, X. Liu, J. Sutiak, hep-ex 0407053

31


Concepts: Focus on the rear/forward acceptance and thus on low-x / high-x physics

• compact system of tracking and central electromagnetic calorimetry inside a magnetic dipole field and calorimetric end-walls outside

I. Abt, A. Caldwell, X. Liu, J. Sutiak, hep-ex 0407053 J. Pasukonis, B.Surrow, physics/0608290

Focus on a wide acceptance detector system similar to HERA experiments• allow for the maximum possible Q2 range.

32

SummaryEIC presents a unique opportunity in high energy nuclear physics and precision QCD physics

Embraced by NSAC in NP Long Range Plan• Recommendation $30M for R&D over next 5 years

EIC Long Term Goal: Start construction in next decade

e+A Polarized e+p Study the Physics of Strong Color Fields

• Establish (or not) the existence of the saturation regime

• Explore non-linear QCD• Measure momentum & space-time of glue

Study the nature of color singlet excitations (Pomerons)

Test and study the limits of universality (eA vs. pA)

Precisely image the sea-quarks and gluons to determine the spin, flavor and spatial structure of the nucleon

EIC Open Collaboration Meeting

Stony Brook University 7-8 December, 2007

http://web.mit.edu/eicc/SBU07/index.html

33



Additional Slides

34

Connection to Other Fields

35

CP Violation

?

Non-linearity,

Confinement,

AdS/QCD

QCD

Background

EIC

QCD Theory

Hadron Structure

(JLAB 12 GeV, RHIC-Spin)

Relativistic

Heavy Ion Physics

(RHIC, LHC & FAIR)

Technology FrontierExamples: beam cooling,

energy recovery linac,

polarized electron source,

superconducting RF

cavities

High Energy

Physics(LHC, LHeC,

Cosmic Rays)

Condensed

Matter Physics Bose-Einstein Condensate

Spin Glasses

Graphene

Lattice QCD New Generation

of Instrumentation

Physics of Strong

Color Fields

ab initio

QCD Calculations

& Computational

Development

Understanding

of Initial Conditions,

Saturation, Energy Loss

Valence ↔ Sea

GPDs

Saturation ModelsColor Glass Condensate

Fundamental

Symmetries

36

Diffractive DIS is …

momentum transfert = (P-P’)2 < 0

diffractive mass of the final stateMX

2 = (P-P’+l-l’)2

… when the hadron/nuclei remains intact

xpom = x/β rapidity gap : Δη = ln(1/xpom)

hadronP

P

β ~ momentum fraction of the struck parton with respect to the Pomeron

xpom ~ momentum fraction of the Pomeron with respect to the hadron

Pomeron

37

EIC Timeline & Status NSAC Long Range Plan 2007

Recommendation: $6M/year for 5 years for machine and detector R&D

Goal for Next Long Range Plan 2012 High-level (top) recommendation for construction

EIC Roadmap (Technology Driven) Finalize Detector Requirements from Physics 2008 Revised/Initial Cost Estimates for eRHIC/ELIC 2008 Investigate Potential Cost Reductions 2009 Establish process for EIC design decision 2010 Conceptual detector designs 2010 R&D to guide EIC design decision 2011 EIC design decision 2011 “MOU’s” with foreign countries? 2012

Why HERA did not do EIC physics?

• eA physics:– Up to Ca beams considered– Low luminosity (1000 compared to EIC)– Would have needed ~$100M to upgrade the source to

have more ions, but still the low luminosity• Polarized e-p physics

– HERA-p ring is not planar– No. of Siberian snake magnets required to polarize beam

estimated to be 6-8: Not enough straight sections for Siberian snakes and not enough space in the tunnel for their cryogenics

– Technically difficult• DESY was a HEP laboratory focused on the high

energy frontier.

39

eA From a “Dipole” Point of View

Coherence length of virtual photon’s fluctuation intoqq: L~ 1/2mN x

valid in the small-x limit

k

k’

p

r : dipole size

L << 2R Energy Loss color transparency EMC effect

L >> 2R Physics of strong color fields Shadowing Diffraction

In the rest frame of the nucleus:Propagation of a small pair, or “color dipole”

40

The EIC Collaboration17C. Aidala, 28E. Aschenauer, 10J. Annand, 1J. Arrington, 26R. Averbeck, 3M. Baker, 26K. Boyle, 28W. Brooks, 28A. Bruell, 19A. Caldwell, 28J.P. Chen, 2R. Choudhury, 10E. Christy, 8B. Cole, 4D. De Florian, 3R. Debbe, 26,24-1A. Deshpande, 18K. Dow, 26A. Drees, 3J. Dunlop, 2D. Dutta, 7F. Ellinghaus, 28R. Ent, 18R. Fatemi, 18W. Franklin, 28D. Gaskell, 16G. Garvey, 12,24-1M. Grosse-Perdekamp, 1K. Hafidi, 18D. Hasell, 26T. Hemmick, 1R. Holt, 8E. Hughes, 22C. Hyde-Wright, 5G. Igo, 14K. Imai, 10D. Ireland, 26B. Jacak, 15P. Jacobs, 28M. Jones, 10R. Kaiser, 17D. Kawall, 11C. Keppel, 7E. Kinney, 18M. Kohl, 9H. Kowalski, 17K. Kumar, 2V. Kumar, 21G. Kyle, 13J. Lajoie, 3M. Lamont, 16M. Leitch, 27A. Levy, 27J. Lichtenstadt, 10K. Livingstone, 20W. Lorenzon, 145. Matis, 12N. Makins, 6G. Mallot, 18M. Miller, 18R. Milner, 2A. Mohanty, 3D. Morrison, 26Y. Ning, 15G. Odyniec, 13C. Ogilvie, 2L. Pant, 26V. Pantuyev, 21S. Pate, 26P. Paul, 12J.-C. Peng, 18R. Redwine, 1P. Reimer, 15H.-G. Ritter, 10G. Rosner, 25A. Sandacz, 7J. Seele, 12R. Seidl, 10B. Seitz, 2P. Shukla, 15E. Sichtermann, 18F. Simon, 3P. Sorensen, 3P. Steinberg, 24M. Stratmann, 22M. Strikman, 18B. Surrow, 18E. Tsentalovich, 11V. Tvaskis, 3T. Ullrich, 3R. Venugopalan, 3W. Vogelsang, 28C. Weiss, 15H. Wieman,15N. Xu,3Z. Xu, 8W. Zajc.

1Argonne National Laboratory, Argonne, IL; 2Bhabha Atomic Research Centre, Mumbai, India; 3Brookhaven National Laboratory, Upton, NY; 4University of Buenos Aires, Argentina; 5University of California, Los Angeles, CA; 6CERN, Geneva, Switzerland; 7University of Colorado, Boulder,CO; 8Columbia University, New York, NY; 9DESY, Hamburg, Germany; 10University of Glasgow, Scotland, United Kingdom; 11Hampton University, Hampton, VA; 12University of I!inois, Urbana-Champaign, IL; 13Iowa State University, Ames, IA; 14University of Kyoto, Japan; 15Lawrence Berkeley National Laboratory, Berkeley, CA; 16Los Alamos National Laboratory, Los Alamos, NM; 17University of Massachusetts, Amherst, MA; 18MIT, Cambridge, MA; 19Max Planck Institüt für Physik, Munich, Germany; 20University of Michigan Ann Arbor, MI; 21New Mexico State University, Las Cruces, NM; 22Old Dominion University, Norfolk, VA; 23Penn State University, PA; 24RIKEN, Wako, Japan; 24-1RIKEN-BNL Research Center, BNL, Upton, NY; 25Soltan Institute for Nuclear Studies, Warsaw, Poland; 26SUNY, Stony Brook, NY; 27Tel Aviv University, Israel; 28Thomas Jefferson National Accelerator Facility, Newport News, VA

96 Scientists, 28 Institutions, 9 countries

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