Summary and Outlook
Roy Holt
23 May 2008
With apologies for
being incomplete
EIC White Papers 2007 – an astounding year
Available at:
• NSAC LRP2007 home page
• Rutgers Town Meeting page
• http://www.bnl.gov/eic
 The Electron Ion Collider (EIC) White
Paper
 The GPD/DVCS White Paper
 Position Paper: e+A Physics at an
Electron Ion Collider
 The eRHIC machine: Accelerator
Position Paper
 ELIC Zero’th Order Design Report
The EIC Working Group
17C.
Aidala, 28E. Aschenauer, 10J. Annand, 1J. Arrington, 26R. Averbeck, 3M. Baker, 26K. Boyle, 28W. Brooks, 28A. Bruell, 19A. Caldwell,
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, 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.
28J.P.
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 Illinois, 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
-95 Scientists, 28 Institutions, 9 countries
*Contact People
NSAC 2007 Long Range Plan
“An Electron-Ion Collider (EIC) with
polarized beams has been embraced by
the U.S. nuclear science community as
embodying the vision for reaching the
next QCD frontier. EIC would provide
unique capabilities for the study of QCD
well beyond those available at existing
facilities worldwide and complementary to
those planned for the next generation of
accelerators in Europe and Asia. In
support of this new direction:
We recommend the allocation of
resources to develop accelerator and
detector technology necessary to lay
the foundation for a polarized Electron
Ion Collider. The EIC would explore the
new QCD frontier of strong color fields
in nuclei and precisely image the
gluons in the proton.”
Introduction
The EIC will explore the most compelling issues in nuclear
science and technology.
 Profound issues in nuclear physics
– Structure of visible matter
– Role of gluons in hadronic matter
– Fundamental symmetries
 New facilities on the horizon
 Concluding statement
Explore the structure of visible matter
 What is the internal landscape of the hadron?
– Benchmark: Spatial, spin, flavor and gluonic
structure
 What is the nature of the nuclear force that
binds protons and neutrons into nuclei?
– Frontier: QCD properties of nuclear force
– Mysteries: QCD effects in nuclei
“If, in some cataclysm, all of scientific knowledge were to be destroyed,
and only one sentence passed on to the next generation, what statement
would contain the most information in the fewest words? I believe it is
the atomic hypothesis, that all things are made of atoms -- little particles
that move around in perpetual motion, attracting each other when they
are a little distance apart, but repelling upon being squeezed into one
another. In that one sentence, there is an enormous amount of
information about the world, if just a little imagination and thinking are
applied.”
- R. Feynman
Explore the structure of the nucleon
• Parton distribution functions
• Longitudinal and transverse spin
distribution functions
• Generalized parton distributions
•Transverse momentum distributions
A. Thomas
E. Kinney
F. Yuan,
D. Hasch,
J. Negele
A. Sidorov
R. Sassot
+ e-p working group
talks
Lattice -> quantitative predictions
Explore the structure of the nucleon (continued)
– Light quark structure – chiral properties
RHIC-Spin region
Neutron structure
function – JLab
C. Keppel et al
Charge symmetry? A. Thomas
Spectator forward tagging to minimize
deuteron structure –similar requirements
as exclusive, DVCS, diffraction:
T. Horn, D. Hasch, M. Derrick, C. Hyde
Explore the structure of the nucleon (continued)
– strange quark distributions
A. Thomas:
Strange quark distribution - HERMES
J. Owens ” more kinematic reach”
-> EIC
What about charm quark distribution?
A. Deshpande
Data on same time scale as disconnected diagrams in lattice calculations.
Generalized Parton Distributions
D. Hasch
Q2
 ~ xBj
x 

q
form factors
eq  dx H ( x,  , t )  F1 (t )
q
x 
 xBj
H ( xt,  , t ) x ~
xBj
PDFs
…
H ( x,0,0)  q( x)
~
H q , g ( x,0,0)  q ( x)
q, g
GPD’s provide a 2D spatial image as a function of x
Consider “Dirac” GPD: H(x,t)
eg, choose r meson:
sensitive to non-singlet or
gluons
C. Weiss
Generalized Parton Distributions
D. Hasch
Lattice – J. Negele
GPD moments
Well documented case,
Progress on detector constraints
- C. Hyde
Luminosity hungry
Positrons useful
EIC Kinematic Reach
HERA
Luminosity(*1030/cm2/s)
D. Hasch
H. Avakian
109
108
107
106
105
104
103
102
101
EIC
JLab@12GeV
JLab
ELIC
107
eRHIC
HERMES
COMPASS
1
10
HERA-collider
100 CM energy (GeV)
Explore the structure of the nucleon (continued)
Transverse Momentum Distributions
 H. Avakian – “Welcome to the exciting world of 3D parton distributions.”
– Transversity, Sivers, pretzelosity, Boer Mulders, …
 A. Bachetta “EIC, a precision machine for TMD’s”
 “Proof of principle” - R. Seidl - measure transversity, Collins
fragmentation function, determine tensor charge
HERMES + Belle
Prohudin - DIS 2008
QCD and the Origin of Mass
99% of the proton’s
mass/energy is due to the selfgenerating gluon field
–Higgs mechanism has
almost no role.
 The similarity of mass
between the proton and neutron
arises from the fact that the
gluon dynamics are the same
–Quarks contribute almost
nothing.

Explore gluon-dominated matter
 What is the role of gluons and gluon self-interactions in nucleons and
nuclei? NSAC-2007
– Gluon dominance in the proton
Gluon distribution G(x,Q2)
• Scaling violation in F2: dF2/dlnQ2
• FL ~ as G(x,Q2)
• inelastic vector meson production
(e.g. J/)
• diffractive vector meson production
~ [G(x,Q2)]2
H. Kowaski, M. Derrick
…
•
EIC: most precise measure of
gluon densities
Recent progress – direct FL measurements from HERA

d 2 epeX 4a 2 
y2 
y2
2
2



1

y

F
(
x
,
Q
)

F
(
x
,
Q
)


2
L
2 
2
dxdQ2
xQ4 

T. Ullrich
EIC – an FL factory
g/g
The Gluon Contribution to the Proton Spin
Projected data on g/g with an
EIC, via g + p  D0 + X
K- + +
Advantage: measurements
directly at fixed Q2 ~ 10
GeV2 scale!
RHIC-Spin
Explore gluon-dominated matter
 What is the role of gluons and gluon self-interactions in nucleons and
nuclei? NSAC-2007
– The nucleus as a “gluon amplifier”
At high gluon density, gluon
recombination should compete with
gluon splitting  density saturation.
Color glass condensate
Oomph factor stands up under scrutiny.
Nuclei greatly extend x reach:
xEIC = xHERA/18 for 10+100 GeV, Au
T. Ullrich, R. Venugopalan,
e-A Working Group talks
Explore the low energy precision frontier
“The task of the physicist is to see through
the appearances down to the underlying,
very simple, symmetric reality.”
- S. Weinberg
Preliminary - EIC
 What are the unseen forces present at
the dawn of the Universe but have
disappeared from view as the universe
evolved? precision electroweak
experiments: sin2qW , …
Questions for the Universe, Quantum
Universe, HEPAP, 2004; NSAC Long
Range Plan, 2007
Relatively high x -> charge symmetry violation?
The LHC is driving global interest in low energy tests of the Standard Model.
What new facilities are essential to this quest?
eRHIC
V. Ptitsy
V. Litvinenko
Polarization:
M. Bai
E. Tsentalovich
D. Barber
W. Lorenzon
ELIC
R. Milner
Cooling:
S. Derbenev
V. Litvinenko
F. Wang
G. Krafft
Crab cavities:
M. Masuzawa
“We recommend the allocation of resources to develop accelerator and
detector technology necessary to lay the foundation for a polarized
Electron-Ion Collider.”
NSAC LRP 2007
Nanofabricated Superconducting RF Composites
M. Pellin, J. Elam, J. Moore, J. Norem, T. Proslier, R. Rimmer, J. Zasadzinski (ANL, IIT, FNAL, JLab)
 Many of the failure modes of SCRF structures
can be traced to defects in the Nb surface.
 Atomic Layer Deposition is a chemical process
capable of coating large and arbitrary shapes.
 Vortices in superconductors move in AC fields –
RF losses
 Vortices are not stable in thin layers
 Began tests of coated cavities at JLab
 Prospects excellent for achieving >50 MV/m
An application of our technology
Hampton University Proton Therapy Institute – online in 2010
Cynthia Keppel – Scientific and Technical Director
World Community in 2015 and Beyond
 Three new major facilities investigating nuclear physics at hadronic
level (QCD): GSI, J-PARC and 12-GeV JLab
 Two new facilities that explore nuclei at the partonic level: RHIC with
upgrades and LHC
 Two new proposed facilities that can take our field to the next level:
EIC, Project X (FNAL)
 Petascale computing facilities are imminent, Exascale is on the way.
 Outstanding opportunities for the future
The International Picture
NuPECC activities
– EIC study group approved at the meeting in
Bucharest on 10/27/2007 with G. Rosner, chair
– Charge is to produce a report outlining:
• The science possibilities
• The interest among European groups
• Possible links with proposals outside Europe
 Glasgow meeting in Fall 2008.

The International Picture (continued)
 OECD (Organization for Economic Co-operation and Development) Global
Science Forum
– Nuclear Physics Working Group- report on ‘optimal evolution of Nuclear
Physics at an international level during the next 10-15 years’
 Membership – 14 countries
 Two projects may be ‘Global’ due to size
– EURISOL
– EIC
F. Willeke, S. Chattopadhyay
Columbus’ vision
Look! Purple mountains! Spacious skies! Fruited plains! …
Is someone writing this down? - adapted from G. Larson
Yes! white papers, NSAC LRP 2007, but we
need an even more compelling case by next NP LRP (2012-13)
Concluding Statement
 EIC research can penetrate some of the most profound mysteries
and questions of 21st century physics.
 Technology is improving at an astounding rate:
– Accelerator design, cavity improvement, energy recovery,
crab cavities, cooling, polarization, polarimetry, detectors,
petascale computing, …
 There are interesting new opportunities worldwide. The next 10
years will be even more exciting than the last 10 years.
 We must put forward a most compelling case for the EIC on the
time scale of the next LRP.
Summary
 Fourth EIC workshop has been a resounding success.
 Clear and substantial progress was demonstrated since
the last EIC workshop.
 Essential to lay the foundation for the next Long Range
Planning Exercise.
must develop a clear path forward.
 Next Workshop - Berkeley - December 11-13, 2008
Peter Jacobs
Many thanks to
Steering Committee
•Abhay Deshpande, Stony Brook, RBRC (Co-Chair/Contact person)
•Rolf Ent, Jlab
•Charles Hyde, ODU/UBP, France
•Peter Jacobs, LBL
Working Groups and Convenors
•Richard Milner, MIT (Co-Chair/Contact person)
•ep Physics
•Thomas Ulrich, BNL
•Antje Bruell, JLAB
•Raju Venugopalan, BNL
•Ernst Sichterman, LBL
•Antje Bruell, Jlab
•Werner Vogelsang, BNL
•Werner Vogelsang, BNL
•Christian Weiss, JLAB
•eA Physics
International Advisory Committee
•Vadim Guzey, JLAB
•Dave Morrison, BNL
 Jochen Bartels (DESY)
•Thomas Ullrich, BNL
 Allen Caldwell (MPI, Munich)
•Raju Venugopalan, BNL
 Albert De Roeck (CERN)
•Detector
 Walter Henning (ANL)
•Elke Aschenauer, JLAB
•Edward Kinney, Colorado
 Dave Hertzog (UIUC)
•Bernd Surrow, MIT
 Xiangdong Ji (U. Maryland)
•Electron Beam Polarimetry
 Robert Klanner (U. Hamburg)
•Wolfgang Lorenzon, Michigan
 Katsunobu Oide (KEK)
 Naohito Saito (KEK)
 Uli Wienands (SLAC)
Many thanks to
Workshop Organizing Committee:
Alberto Accardi - Hampton/JLab
Andrei Afanasev - Hampton/JLab
Eric Christy - Hampton
Abhay Deshpande - Stony Brook/RBRC
Rolf Ent - JLab/Hampton
Cynthia Keppel - Hampton/JLab
Lia Merminga - JLab
Richard Milner - MIT
Thomas Roser - BNL