Nucleon Structure Study with e-N Jian-ping Chen ( 陈剑平 ), Jefferson Lab, Virginia, USA EIC 物理研讨会,Weihai, China, July 29, 2013  Introduction  Polarized e-N facilities: JLab/12 GeV, EIC, …  Examples of Golden Physics Cases Spin Structure 3-d Structure of the Nucleon (GPDs, TMDs)  K Structure Functions others: Form Factor, Hadron Spectroscopy, Parity Violation e-N  Unique Opportunities for

Introduction Nucleon Structure,QCD and e-N

Major Challenge: Non-perturbative QCD/Confinement 2004 Nobel prize for ``asymptotic freedom’’ non-perturbative regime QCD ? confinement One of the top 10 challenges for physics! QCD: Important for discovering new physics beyond SM Nucleon structure is one of the most active areas running coupling “constant”

History of Nucleon Structure Study  1933: First (Indirect) Evidence of Proton Structure magnetic moment of the proton:  p =eћ/2m p c(1+  p ) ! anomalous magnetic moment:  p = %  1960s: Discovery: Proton Has Internal Structure elastic electron scattering  1970s: Discovery of Quarks (Partons) deep-inelastic scattering  1970s-2000s: Parton Distributions  1980s-2010s: Spin Distributions  2000s-: 3-d Structure Otto Stern Nobel Prize 1943 J.T. Friedman R. Taylor H.W. Kendall Nobel Prize 1990 Robert Hofstadter, Nobel Prize 1961

Nucleon Structure: A Universe Inside Nucleon: proton =(uud), neutron=(udd) + sea + gluons Global properties and structure: full of surprises Mass: 99% of the visible mass in universe ~1 GeV, but u/d quark mass only a few MeV each! Lattice QCD: vacuum condensation Charge and magnetic distributions: very different Momentum: quarks carry ~ 50% Spin: ½, but total quarks contribution only ~30% Orbital angular momentum is important Transverse (3-d) structure: GPDs and TMDs …

Nucleon Structure Function: Deep-Inelastic Scattering Bjorken Scaling and Scaling Violation Gluon radiation – QCD evolution One of the best experimental tests of QCD

QCD and Nucleon Structure Study Dynamical Chiral Symmetry Breaking Confinement ?  Responsible for ~98% of the nucleon mass  Higgs mechanism is (almost) irrelevant to light quarks Rapid development in theory  Lattice QCD  Dyson-Schwinger  Ads/CFT: Holographic QCD  …… Direct comparisons limited to  Moments  Tensor charge  … Direct comparison becomes possible  Experimental data with predictions from theory Mass from nothing! C.D. Roberts, Prog. Part. Nucl. Phys. 61 (2008) 50Prog. Part. Nucl. Phys. 61 (2008) 50 M. Bhagwat & P.C. Tandy, AIP Conf.Proc. 842 (2006) AIP Conf.Proc. 842 (2006)

Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 8  Established an one-to-one connection between DCSB and the pointwise form of the pion’s wave function.  Dilation measures the rate at which dressed-quark approaches the asymptotic bare-parton limit  Experiments at JLab12 can empirically verify the behaviour of M(p), and hence chart the IR limit of QCD C.D. Roberts, Prog. Part. Nucl. Phys. 61 (2008) 50Prog. Part. Nucl. Phys. 61 (2008) 50 Dilation of pion’s wave function is measurable in pion’s electromagnetic form factor at JLab12 A-rated: E E Imaging dynamical chiral symmetry breaking: pion wave function on the light front, Lei Chang, et al., arXiv: [nucl-th], Phys. Rev. Lett. 110 (2013) (2013) [5 pages].arXiv: [nucl-th]Phys. Rev. Lett. 110 (2013) (2013) [5 pages] Pion’s valence-quark Distribution Amplitude Dyson-Schwinger

New progress in Lattice QCD Using the Infinite Momentum Frame formalism. Using the Infinite Momentum Frame formalism. Start with static correlation in the z-direction. Start with static correlation in the z-direction. Can be extended to TMDs and GPDs. Can be extended to TMDs and GPDs. First exploratory study by Huey-Wen Lin presented at First exploratory study by Huey-Wen Lin presented at the QCD Evolution Workshop at JLab, May X. Ji

Lepton-Nucleon Facilities JLab 6 GeV/12 GeV, EIC

Jefferson Lab at a Glance  ~ 1400 Active Users  ~ 800 FTEs  178 Completed 6 GeV  Produces ~1/3 of US PhDs in Nuclear Physics A B C CEBAF  High-intensity electron accelerator based on CW SRF technology  E max = 6 GeV  I max = 200  A  Pol max = 85%  L~ (unpolarized) ~ (polarized) A B C  12 GeV

12 GeV Upgrade Maintain capability to deliver lower pass beam energies : 2.2, 4.4, 6.6,….  Enhanced capabilities in existing Halls  High Luminosity  ~10 39 cm -2 s -1  Enhanced capabilities in existing Halls  High Luminosity  ~10 39 cm -2 s -1 The completion of the 12 GeV Upgrade of CEBAF was ranked the highest priority in the 2007 NSAC Long Range Plan. New Hall CHL-2 20 cryomodules Add 5 cryomodules Add 5 cryomodules 20 cryomodules Add arc

JLab Physics Program at 12 GeV 13 Hall C – precision determination of valence quark properties in nucleons and nuclei high momentum spectrometers & dedicated equipments Hall B - 3-D nucleon structure via GPDs & TMDs Search new form of hadron. matter via Meson Spectr. 4  detector Hall A – form factors, GPDs & TMDs, SRC Low-energy tests of the SM and Fund. Symmetry Exp SoLID, MOLLER. High luminosity, high resolution & dedicated equipments Hall D - exploring origin of confinement by studying exotic mesons using real photons Hermetic detector Photon tagger Hall A Hall B Hall C Hall D

H1, ZEUS JLab Upgrade 11 GeV H1, ZEUS 12 GeV 11 GeV 27 GeV 200 GeV W = 2 GeV 0.7 HERMES COMPASS The 12 GeV Upgrade is well matched to studies in the valence quark regime.

EIC: Science Motivation A High Luminosity, High Energy Electron-Ion Collider: A New Experimental Quest to Study the Sea and Glue How do we understand the visible matter in our universe in terms of the fundamental quarks and gluons of QCD? Precisely image the sea-quarks and gluons in the nucleon: How do the gluons and sea-quarks contribute to the spin structure of the nucleon? What are the 3d distributions of the gluons and sea quarks in the nucleon? How do hadronic final-states form in QCD? Explore the new QCD frontier: strong color fields in nuclei: How do the gluons contribute to the structure of the nucleus? What are the properties of high density gluon matter? How do fast quarks or gluons interact as they traverse nuclear matter?

2010 NRC Decadal Study

RHIC  eRHIC LHC  LHeC CEBAF  MEIC/EIC FAIR  ENC HERA 17 Electron Ion Colliders on the World Map

12 GeV With 12 GeV we study mostly the valence quark component An EIC aims to study gluon dominated matter. The Landscape of EIC mEIC EIC

Lepton-Nucleon Facilities JLAB12 HIAF HIAF: e(3GeV) +p(12GeV), both polarized, L(max)=4*10 32 cm 2 /s

Figure of Merit Figure-of Merit for double polarization FOM=L * P e 2 * P N 2 * D 2 L=Luminosity, P=Polarization, D=Dilution FOM Comparison of (1) with COMPASS (2) HIAF: L=4*10 32, D=1 COMPASS: L=10 32, D=0.13 (NH 3 target) Unpolarized: FOM(1)/FOM(2) = L(1)/L(2) ~ 4 Polarized: FOM(1)/FOM(2) = L(1)/L(2) * [D(1) 2 /D(2) 2 ] ~ 200

Medium Energy JLab Concept Initial configuration (MEIC): 3-12 GeV on GeV ep/eA collider Fully-polarized, longitudinal and transverse Luminosity: up to few x e-nucleons cm -2 s -1 Upgradable to higher energies 250 GeV protons + 20 GeV electrons

solenoid electron FFQs 50 mrad 0 mrad ion dipole w/ detectors ions electrons IP ion FFQs 2+3 m 2 m Detect particles with angles below 0.5 o beyond ion FFQs and in arcs. Need 4 m machine element free region detectors Central detector Detect particles with angles down to 0.5 o before ion FFQs. Need 1-2 Tm dipole. EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter Solenoid yoke + Muon Detector TOF HTCC RICH RICH or DIRC/LTCC Tracking 2m 3m 2m 4-5m Solenoid yoke + Hadronic Calorimeter Very-forward detector Large dipole 20 meter from IP (to correct the 50 mr ion horizontal crossing angle) allows for very-small angle detection (<0.3 o ). Need 20 m machine element free region Full MEIC: Full Acceptance Detector 7 meters Three-stage detection

MEIC Point Design Parameters Detector typeFull acceptance high luminosity & Large Acceptance ProtonElectronProton Electron Beam energyGeV605 5 Collision frequencyMHz750 Particles per bunch Beam CurrentA Polarization%> 70~ 80> 70 ~ 80 Energy spread10 -4 ~ 37.1~ RMS bunch lengthmm Horizontal emittance, normalizedµm rad Vertical emittance, normalizedµm rad Horizontal and vertical β*cm10 and 2 4 and 0.8 Vertical beam-beam tune shift Laslett tune shift0.06Very small0.06 Very small Distance from IP to 1 st FF quadm Luminosity per IP, cm -2 s

Ongoing MEIC Accelerator R&D Space Charge Dominated Ion Beam in the Pre-booster  Simulation study is in progress by Argonne-NIU collaborators Beam Synchronization  A scheme has been developed; SRF cavity frequency tunability study is in progress Beam-Beam Interaction  Phase 1 simulation study was completed Interaction Region, Chromaticity Compensation and Dynamic Aperture  Detector integration with IR design has been completed, offering excellent acceptance  Correction scheme has been developed, and incorporated into the IR design  Tracking simulations show excellent momentum acceptance; dynamic aperture is increased  Further optimization in progress (e.g., all magnet spaces/sizes defined for IR +/- 100 m) Beam Polarization  Electron spin matching and tracking simulations are in progress, achieving acceptable equilibrium polarization and lifetime (collaboration with DESY)  New ion polarization scheme and spin rotators have been developed (collaboration with Russian group) – numerical demonstration of figure-8 concept with misalignments ongoing Electron Cloud in Ion Ring Ion Sources (Polarized and Universal)

Proposed Cooling Experiments at IMP Idea: pulse the beam from the existing thermionic gun using the grid (Hongwei Zhao) Non-invasive experiment to a user facility Proposed experiments Demonstrate cooling of a DC ion beam by a bunched electron cooling (Hutton) Demonstrate a new phenomena: longitudinal bunching of a bunched electron cooling (Hutton) (Next phase) Demonstrate cooling of bunched ion beams by a bunched electron beam (need an RF cavity for bunching the ion beams) DC cooler Two storage rings for Heavy ion coasting beam

EIC Realization Imagined Assumes endorsement for an EIC at the next NSAC Long Range Plan Assumes relevant accelerator R&D for down-select process done around 2016 Activity Name GeV Upgrade FRIB EIC Physics Case NSAC LRP EIC CD0 EIC Machine Design/R&D EIC CD1/Downsel EIC CD2/CD3 EIC Construction

Phase Space for Polarized Data/EIC x = Q 2 /ys (x,Q 2 ) phase space directly correlated with s (=4E e E p ) Q 2 = 1 lowest x scales like s Q 2 = 10 lowest x scales as 10s -1

Kinematic Coverage Comparison with JLab 12 GeV e(3GeV) +p(12GeV), both polarized, L(max)=4*10 32 cm 2 /s study sea quarks (x > 0.01) deep exclusive scattering at Q 2 > 5-10 higher Q 2 in valance region range in Q 2 allows study gluons plot courtesy of Xurong Chen

The Science of eRHIC/MEIC Goal: Explore and Understand QCD: Map the spin and spatial structure of quarks and gluons in nucleons Discover the collective effects of gluons in atomic nuclei (role of gluons in nuclei & onset of saturation) Emerging Themes: Understand the emergence of hadronic matter from quarks and gluons & EW The Science of One Main Goal: Explore Hadron Structure Map the spin-flavor, multi-d structure of sea & valence quarks Science Goals

Science Case (I): Nucleon Spin-Flavor Structure Polarized Sea Quark

Three Decades of Nucleon Spin Structure Study 1980s: EMC (CERN) + early SLAC quark contribution to proton spin is very small  = ( )% ! ‘spin crisis’ 1990s: SLAC, SMC (CERN), HERMES (DESY)  = 20-30% the rest: gluon and quark orbital angular momentum spin sum rule: (½)  + Lq + J G =1/2 (Ji) others: Jaffe, Chen et al., … Bjorken Sum Rule verified to <10% level 2000s: COMPASS (CERN), HERMES, RHIC-Spin, JLab, … :  ~ 30%;  G probably small (~0.1)?, orbital angular momentum significant?  Valence quark structure  Transverse Spin, TMDs  GPDs

Polarized Structure Function/Distributions

33

JLab E99117: Precision Measurement of A 1 n at High-x PRL 92, (2004), PRC 70, (2004 ) Physics News Update, Science Now Science News, Physics Today Update

A 1 p at 11 GeV Planned JLab 12 GeV Experiments

100 days, L =10 33, s = 1000 Sea Quark Polarization Spin-Flavor Decomposition of the Light Quark Sea Access requires s ~ (and good luminosity) Xiaodong Jiang (Los Alamos) is doing simulation with parameters of } Kinney, Seele

how effective are scaling violations at the EIC… what about the uncertainties on the x-shape …

Spin-Flavor Study at Unique opportunity for  s energy reach current fragmentation region for Kaon tagging in SIDIS Significant improvement for  u_bar,  d_bar from SIDIS combination of energy and luminosity Increase in Q 2 range/precision for g 1 (and g 2 ) constraint on  g.

Science Case (II): 3-D Structure Generalized Parton Distributions

W p u (x,k T,r ) Wigner distributions (X. Ji ) d2kTd2kT PDFs f 1 u (x),.. h 1 u (x)‏ GPDs/IPDs d 2 k T dr z d3rd3r TMD PDFs f 1 u (x,k T ),.. h 1 u (x,k T )‏ 3D imaging 5D Dist. Form Factors G E (Q 2 ), G M (Q 2 )‏ d2rTd2rT dx & Fourier Transformation 1D

TMDs 2+1 D picture in momentum space Bacchetta, Conti, Radici GPDs 2+1 D picture in impact-parameter space QCDSF collaboration 3-D Imaging - Two Approaches intrinsic transverse motion spin-orbit correlations- relate to OAM non-trivial factorization accessible in SIDIS (and Drell-Yan) collinear but long. momentum transfer indicator of OAM; access to Ji’s total J q,g existing factorization proofs DVCS, exclusive vector-meson production

transverse polarized target 3D Images of the Proton’s Quark Content M. Burkardt PRD 66, (2002) b - Impact parameter T u(x,b ) T d(x,b ) T u X (x,b ) T d X (x,b ) T HuHu EuEu Needs:HdHd EdEd quark flavor polarization Accessed in Single Spin Asymmetries.

Access GPDs through DVCS x-section & asymmetries Accessed by cross sections Accessed by beam/target spin asymmetry t=0 Quark distribution q(x) -q(-x) DIS measures at  =0

Quark Angular Momentum → Access to quark orbital angular momentum

CLAS12 - DVCS/BH Target Asymmetry e p ep  = 2.0GeV 2 = 0.2 = 0.25GeV 2 CLAS preliminary E=5.75 GeV A UL Longitudinally polarized target  ~sin  Im{F 1 H +  (F 1 +F 2 ) H... }d  ~ E = 11 GeV L = 2x10 35 cm -2 s -1 T = 1000 hrs  Q 2 = 1GeV 2  x = 0.05

Detailed differential images from nucleon’s partonic structure EIC: Gluon size from J/  and  electroproduction (Q 2 > 10 GeV 2 ) [Transverse distribution derived directly from t  dependence] t Hints from HERA: Area (q + q) > Area (g) Dynamical models predict difference: pion cloud, constituent quark picture - t EIC: singlet quark size from deeply virtual compton scattering EIC: strange and non-strange (sea) quark size from  and K production Q 2 > 10 GeV 2 for factorization Statistics hungry at high Q 2 ! Weiss, Hyde, Horn Fazio Horn

Charles Hyde (ODU)

GPD Study at Unique opportunity for DVMP (pion/Kaon) flavor decomposition needs DVMP energy reach Q 2 > 5-10 GeV 2, scaling region for exclusive light meson production (JLab12 energy not high enough to have clean meson deep exclusive process) Significant increase in range for DVCS combination of energy and luminosity Other opportunities: vector meson, heavy flavors?

Science Case (III): 3-D Structure Transverse Momentum-Dependent Distributions (Haiyan Gao’s talk)

Nucleon Structure (TMDs) with SoLID (JLab) Semi-inclusive Deep Inelastic Scattering program: Large Acceptance + High Luminosity + Polarized targets  4-D mapping of asymmetries  Tensor charge, TMDs …  Lattice QCD, QCD Dynamics, Models. International collaboration (8 countries, 50+ institutes and 190+ collaborators) Rapid Growth in US‐China Collaboration Chinese Hadron collaboration (USTC, CIAE, PKU, Tsinghua U, Lanzhou, IMP,+) - large GEM trackers - MRPC-TOF 3 A rated SIDIS experiments approved for SoLID with 2 having Chinese collaborators as co-spokesperson (Li from CIAE and Yan from USTC) Solenoidal Large Intensity Device (SoLID)

E /E , Both Approved with “A” Rating Mapping of Collins(Sivers) Asymmetries with SoLID Both  + and  - Precision Map in region x( ) z( ) Q 2 (1-8) P T (0-1.6) <10% d quark tensor charge Collins Asymmetry

Green (Blue) Points: SoLID projections for polarized NH 3 ( 3 He/n) target Luminosity: (10 36 ) (1/cm 2 /s); Time: 120 (90) days Black points: projections for 3 GeV e and 12 GeV p Luminosity: 4 x /cm 2 /s; Time: 200 days The TMD simulation: Projections for SIDIS Asymmetry π + Hiayan Gao (Duke) reach high precision similar to SoLID at lower x, higher Q2 region

TMD Study at Unique opportunity for TMD in “sea quark” region reach x ~ 0.01 Significant increase in Q 2 range for valence region energy reach Q 2 ~40 GeV 2 at x ~ 0.4 Significant increase in P T range reach >1 GeV (TMD/co-linear overlap region)

Science Case (IV):  /K Structure  Parton Distribution Function in Valence Quark Region

Parton Structure of Hadrons  Valence-quark structure of hadrons –Definitive of a hadron – it’s how we tell a proton from a neutron –Expresses charge; flavour; baryon number; and other Poincaré-invariant macroscopic quantum numbers –Via evolution, determines background at LHC  Sea-quark distributions –Flavour content, asymmetry, intrinsic: yes or no?  Any nontrivial answers are essentially nonperturbative features of QCD Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 56 Craig Roberts (Argonne)

Parton Structure of Hadrons  Light front provides a link with quantum mechanics –If a probability interpretation is ever valid, it’s in the infinite-momentum frame  Enormous amount of intuitively expressive information about hadrons & processes involving them is encoded in –Parton distribution functions –Generalised parton distribution functions –Transverse-momentum-dependent parton distribution functions  Information will be revealed by the measurement of these functions – so long as they can be calculated Success of program demands very close collaboration between experiment and theory Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 57

Pion Valence-quark Distribution  Need for calculation is emphasized by Saga of pion’s valence- quark distribution: o 1989: u v π ~ (1-x) 1 – inferred from LO-Drell-Yan & disagrees with QCD; o 2001: DSE- QCD predicts u v π ~ (1-x) 2 argues that distribution inferred from data can’t be correct; Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 58

Pion Valence-quark Distribution  Need for calculation is emphasized by Saga of pion’s valence- quark distribution: o 1989: u v π ~ (1-x) 1 – inferred from LO-Drell-Yan & disagrees with QCD; o 2001: DSE- QCD predicts u v π ~ (1-x) 2 argues that distribution inferred from data can’t be correct; o 2010: NLO reanalysis including soft-gluon resummation, inferred distribution agrees with DSE and QCD Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 59

High-impact large-x measurements  Pion PDF on the valence-quark domain –What is the pointwise structure of Goldstone modes: massless bound-states of very massive constituents? –Currently, a single reanalysis of an old experiment agrees with one (DSE) prediction –Simulations at EIC-kinematics exist: Holt & Reimer AIP Conf.Proc. 588 (2001) AIP Conf.Proc. 588 (2001)  Kaon PDF on the valence-quark domain –Critical complement to pion: x=1 measures strength of DCSB –Need EIC-kinematics: kaon structure function [p(e,e’Λ)] 2nd Conference on QCD & Hadron Physics Craig Roberts: Meaning of Parton Distributions Tu (36p) 60 Simulated errors for DIS events using 5 GeV electron beam on a 25 GeV proton beam with luminosity cm -2 s -1 and 10 6 s running.

projections for 3 GeV e and 12 GeV p Luminosity: 5 x /cm 2 /s; Time:10 6 seconds  structure simulation for Paul Reimei (Argonne)

Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 62  Established an one-to-one connection between DCSB and the pointwise form of the pion’s wave function.  Dilation measures the rate at which dressed-quark approaches the asymptotic bare-parton limit  Experiments at JLab12 can empirically verify the behaviour of M(p), and hence chart the IR limit of QCD C.D. Roberts, Prog. Part. Nucl. Phys. 61 (2008) 50Prog. Part. Nucl. Phys. 61 (2008) 50 Dilation of pion’s wave function is measurable in pion’s electromagnetic form factor at JLab12 A-rated: E E Imaging dynamical chiral symmetry breaking: pion wave function on the light front, Lei Chang, et al., arXiv: [nucl-th], Phys. Rev. Lett. 110 (2013) (2013) [5 pages].arXiv: [nucl-th]Phys. Rev. Lett. 110 (2013) (2013) [5 pages] Pion’s valence-quark Distribution Amplitude Dyson-Schwinger

Lattice comparison Pion’s valence-quark PDA  Employ the generalised-Gegenbauer method described previously (and in Phys. Rev. Lett. 110 (2013) (2013) [5 pages] ). Phys. Rev. Lett. 110 (2013) (2013) [5 pages] Hall-A Collaboration Meeting: June 2013 Craig Roberts: Mapping Parton Structure and Correlations (62p) 63  Lattice-QCD => one nontrivial moment: = 0.27 ± 0.04  Legend Solid = DB (Best) DSE Dashed = RL DSE Dotted (black) = 6 x (1-x) Dot-dashed = midpoint lattice; and the yellow shading exhibits band allowed by lattice errors φ π ~ x α (1-x) α α= = = 0.11 DB α=0.31 but 10% a 2 <0 RL α=0.29 and 0% a 2 V. Braun et al., PRD 74 (2006) Pion distribution amplitude from lattice-QCD, I.C. Cloët et al. arXiv: [nucl-th]arXiv: [nucl-th]

Physics Programs at Opportunity to bring Chinese hadron physics to the forefront in the world Nucleon spin-flavor structure (polarized sea,  s) 3-d Structure: GPDs (Deep-Virtual Meson Production, pion/Kaon) Unique opportunity for TMD in “sea quark” region and significant increase in Q 2 / P T range for valence region Pion/Kaon structure functions e-A to study hadronization EMC-SRC in e-A …… 2 nd Conference on QCD and Hadron Physics: Whitepaper on is being worked on

Other Physics Programs E-A programs (not covered): Hadronization, EMC-SRC Other e-N programs: Nucleon Form Factors Hadron Spectroscopy Parity Violating e-N

Form Factor Measurements at Fast Falling of Form Factors and Elastic Cross Sections Needs very high luminosity Luminosity comparison: JLab: >10 38 unpolarized, >10 36 polarized Limited role for in nucleon form factor study

Hadron Spectroscopy Measurements with an EIC? e+e- (Bella, BaBar, BES): charmonium states: x-y-z search for new states. JLab12: GlueX search for gluon excitation Search for new hadron states No obvious advantage, probably limited role for EIC, including

68 PV e-p: Completed, planned (JLab12), and possible ELIC/ERHIC measurements  EIC allows to probe the electro-weak mixing angle over a wide range of Q

Parity Violating e-N at Need high precision asymmetry increase with energy JLab12 with L~ 5x10 38 ELIC/E-RHIC 50x200 with L ~ x12 with L ~ : not enough precision?

Summary Nucleon Structure Study: Discoveries and Surprises Understand strong interaction/nucleon structure: remains a challenge JLab facility/12 GeV upgrade (Planned) EIC facilities Examples of “Golden Experiments” Nucleon spin-flavor structure (polarizd sea,  s) 3-d Structure: GPDs (DVMP) and DVCS 3-d Structure: TMDs (sea, range in Q 2, P T ) Form factors/Spectroscopy/Parity violation e-N opens up a new window to study/understand nucleon structure, especially the sea Will be at the forefront in the world hadron physics for one decade Exciting new opportunities  lead to breakthroughs?