1. Thomas Jefferson National Accelerator Facility Page 1 SPIN2006, October 7, 2006, 1 Future Spin Physics at JLab 12 GeV and Beyond Kees de Jager Jefferson Lab SPIN2006 Kyoto October 2-7, 2006

2. Thomas Jefferson National Accelerator Facility Page 2 SPIN2006, October 7, 2006, 2 Highlights of the 12 GeV Program Revolutionize Our Knowledge of Spin and Flavor Dependence of PDFS in the Valence Region Strongly Enhance Our Knowledge of Distribution of Charge and Current in the Nucleon Totally New View of Hadron (and Nuclear) Structure: GPDs  Determination of the quark angular momentum Exploration of QCD in the Nonperturbative Regime:  Existence and properties of QCD flux-tube excitations New Paradigm for Nuclear Physics: Nuclear Structure in Terms of QCD  Spin and flavor dependent EMC Effect  Study quark propagation through nuclear matter Precision Tests of the Standard Model  Factor 20 improvement in (2C 2u -C 2d ) electron-quark couplings  Determination of sin 2  w to within 0.00025

3. Thomas Jefferson National Accelerator Facility Page 3 SPIN2006, October 7, 2006, 3 Examples of the 12 GeV Upgrade Research Parton Distribution Functions Form Factors Generalized Parton Distributions Exotic Meson Spectroscopy: Confinement and the QCD vacuum Nuclei at the level of quarks and gluons Tests of Physics Beyond the Standard Model

4. Thomas Jefferson National Accelerator Facility Page 4 SPIN2006, October 7, 2006, 4 Hall A at 11 GeV with BigBite 12 GeV : Unambiguous Flavor Structure x —> 1 After 35 years: Miserable Lack of Knowledge of Valence d-Quarks di-quark correlations pQCD

5. Thomas Jefferson National Accelerator Facility Page 5 SPIN2006, October 7, 2006, 5 A 1 p at 11 GeV Unambiguous Resolution of Valence Spin A 1 n at 11 GeV

6. Thomas Jefferson National Accelerator Facility Page 6 SPIN2006, October 7, 2006, 6 At RHIC with W production At JLab with 12 GeV upgrade Stops at x ≈ 0.5 AND needs valence d(x) Complements Spin-Flavor Dependence at RHIC 12

7. Thomas Jefferson National Accelerator Facility Page 7 SPIN2006, October 7, 2006, 7 Parton Distribution Functions Form Factors Generalized Parton Distributions Exotic Meson Spectroscopy: Confinement and the QCD vacuum Nuclei at the level of quarks and gluons Tests of Physics Beyond the Standard Model Examples of the 12 GeV Upgrade Research

8. Thomas Jefferson National Accelerator Facility Page 8 SPIN2006, October 7, 2006, 8 Proton Neutron Electric Magnetic Experiments at 11 GeV will extend data To 5 GeV 2 To 15 GeV 2 To 14 GeV 2

9. Thomas Jefferson National Accelerator Facility Page 9 SPIN2006, October 7, 2006, 9 Examples of the 12 GeV Upgrade Research Parton Distribution Functions Form Factors Generalized Parton Distributions Exotic Meson Spectroscopy: Confinement and the QCD vacuum Nuclei at the level of quarks and gluons Tests of Physics Beyond the Standard Model

10. Thomas Jefferson National Accelerator Facility Page 10 SPIN2006, October 7, 2006, 10 The Next Generation of Proton Structure Experiments Elastic Scattering transverse quark distribution in Coordinate space DIS longitudinal quark distribution in momentum space GPDs The fully-correlated Quark distribution in both coordinate and momentum space

11. Thomas Jefferson National Accelerator Facility Page 11 SPIN2006, October 7, 2006, 11 Generalized Parton Distributions (GPDs): New Insight into Hadron Structure     J G =  1 1 )0,,()0,,( 2 1 2 1 xExHxdxJ qqq Quark angular momentum (Ji’s sum rule) X. Ji, Phy.Rev.Lett.78,610(1997) e.g. Flavor separation through Deeply Virtual Meson Production

12. Thomas Jefferson National Accelerator Facility Page 12 SPIN2006, October 7, 2006, 12 Access GPDs through x-section and asymmetries Accessed by cross sections Accessed by beam/target spin asymmetry t = 0 Quark distribution q(x) -q(-x) DIS measures at  =0 Flavor separation through DVMP

13. Thomas Jefferson National Accelerator Facility Page 13 SPIN2006, October 7, 2006, 13 Exclusive  0 with transverse target Asymmetry depends linearly on the GPD E, which enters Ji’s sum rule A ~ (2H u +H d ) B ~ (2E u + E d )  L dominance  Q 2 =1 -t = 0.5GeV 2  t = 0.2 L=10 35 cm -2 s -1 2000hrs A UT  K. Goeke, M.V. Polyakov, M. Vanderhaeghen, 2001 xBxB

14. Thomas Jefferson National Accelerator Facility Page 14 SPIN2006, October 7, 2006, 14 Examples of the 12 GeV Upgrade Research Parton Distribution Functions Form Factors Generalized Parton Distributions Exotic Meson Spectroscopy: Confinement and the QCD vacuum Nuclei at the level of quarks and gluons Tests of Physics Beyond the Standard Model

15. Thomas Jefferson National Accelerator Facility Page 15 SPIN2006, October 7, 2006, 15 Gluonic Excitations and the Origin of Confinement Confinement is due to the formation of “Flux tubes” arising from the self- interaction of the glue, leading to a linear confining potential Experimentally, we want to “pluck” the flux tube and see how it responds Hybrid mesons Normal mesons ~1 GeV mass difference J pc = 1 -+ An excited flux tube gives rise to hybrid mesons with conventional and exotic quantum numbers J PC

16. Thomas Jefferson National Accelerator Facility Page 16 SPIN2006, October 7, 2006, 16 Glueballs and hybrid mesons Colin Morningstar: Gluonic Excitations workshop, 2003 (JLab)

17. Thomas Jefferson National Accelerator Facility Page 17 SPIN2006, October 7, 2006, 17 Physics goals and key features The physics goal of GlueX is to map the spectrum of hybrid mesons in a mass range 1.5 to 2.5 GeV, starting with those with the unique signature of exotic J PC Identifying J PC requires an amplitude analysis which in turn requires  linearly polarized photons  detector with excellent acceptance and resolution  sensitivity to a wide variety of decay modes In addition, sensitivity to hybrid masses up to 2.5 GeV requires 9 GeV photons which will be produced using coherent bremsstrahlung from 12 GeV electrons Final states include photons and charged particles and require particle identification Hermetic detector with large acceptance for charged and neutral particles

18. Thomas Jefferson National Accelerator Facility Page 18 SPIN2006, October 7, 2006, 18 Examples of the 12 GeV Upgrade Research Parton Distribution Functions Form Factors Generalized Parton Distributions Exotic Meson Spectroscopy: Confinement and the QCD vacuum Nuclei at the level of quarks and gluons Tests of Physics Beyond the Standard Model

19. Thomas Jefferson National Accelerator Facility Page 19 SPIN2006, October 7, 2006, 19 Observation stunned and electrified the HEP and Nuclear communities 20 years ago Nearly 1,000 papers have been generated….. What is it that alters the quark momentum in the nucleus? Classic I llustration: The EMC effect J. Ashman et al., Z. Phys. C57, 211 (1993) J. Gomez et al., Phys. Rev. D49, 4348 (1994) The EMC Effect: Nuclear PDFs

20. Thomas Jefferson National Accelerator Facility Page 20 SPIN2006, October 7, 2006, 20 Unpacking the EMC effect With 12 GeV, we have a variety of tools to unravel the EMC effect:  Parton model ideas are valid over fairly wide kinematic range  High luminosity  High polarization New experiments, including several major programs:  Precision study of A-dependence; x>1; valence vs. sea  g 1A (x) “Polarized EMC effect” – influence of nucleus on spin  Flavor-tagged polarized structure functions  u A (x A ) and  d A (x A )  x dependence of axial-vector current in nuclei (can study via parity violation)  Nucleon-tagged structure functions from 2 H and 3 He  Study x-dependence of exclusive channels on light nuclei, sum up to EMC

21. Thomas Jefferson National Accelerator Facility Page 21 SPIN2006, October 7, 2006, 21 Examples of the 12 GeV Upgrade Research Parton Distribution Functions Form Factors Generalized Parton Distributions Exotic Meson Spectroscopy: Confinement and the QCD vacuum Nuclei at the level of quarks and gluons Tests of Physics Beyond the Standard Model

22. Thomas Jefferson National Accelerator Facility Page 22 SPIN2006, October 7, 2006, 22 PV DIS at 11 GeV with an LD 2 target 6 GeV experiment will launche PV DIS measurements at JLab 11 GeV experiment requires tight control of normalization errors Important constraint should LHC see anomaly e-e- N X e-e- Z*Z* ** For an isoscalar target like 2 H, structure functions largely cancel in the ratio: (Q 2 >> 1 GeV 2, W 2 >> 4 GeV 2, x ~ 0.3-0.5) Must measure A PV to 0.5% fractional accuracy Luminosity and beam quality available at JLab

23. Thomas Jefferson National Accelerator Facility Page 23 SPIN2006, October 7, 2006, 23 1% A PV measurements Precision High-x Physics with PV DIS Charge Symmetry Violation (CSV) at High x: clean observation possible Global fits allow 3 times larger effects Allows d/u measurement on a single proton! Longstanding issue: d/u as x  1 For hydrogen 1 H: Londergan & Thomas Direct observation of CSV at parton-level Implications for high-energy collider pdfs Could explain large portion of the NuTeV anomaly Need 1% A PV measurement at x ~ 0.75

24. Thomas Jefferson National Accelerator Facility Page 24 SPIN2006, October 7, 2006, 24 Comparable to single Z pole measurement: shed light on disagreement Best low energy measurement until ILC or -Factory Could be launched ~ 2015 Future Possibilities (Purely Leptonic) -e in reactor can test neutrino coupling: sin 2  W to ± 0.002 Møller at 11 GeV at Jlab sin 2  W to ± 0.00025!  ee ~ 25 TeV reach! Higher luminosity and acceptance JLab e2e @ 12 GeV e.g. Z’ reach ~ 2.5 TeV Does Supersymmetry (SUSY) provide a candidate for dark matter? Neutralino is stable if baryon (B) and lepton (L) numbers are conserved B and L need not be conserved (RPV): neutralino decay

25. Thomas Jefferson National Accelerator Facility Page 25 SPIN2006, October 7, 2006, 25CHL-2 Upgrade magnets and power supplies Enhance equipment in existing halls 6 GeV CEBAF 11 12 Add new hall

26. Thomas Jefferson National Accelerator Facility Page 26 SPIN2006, October 7, 2006, 26 HALL A - 12 GeV Upgrade Summary Infrastructure for Large Installations

27. Thomas Jefferson National Accelerator Facility Page 27 SPIN2006, October 7, 2006, 27 A Vision for Precision PV DIS Physics Hydrogen and Deuterium targets Better than 2% errors  It is unlikely that any effects are larger than 10% x-range 0.25-0.75 W 2 well over 4 GeV 2 Q 2 range a factor of 2 for each x  (Except x~0.75) Moderate running times CW 90 µA at 11 GeV 40 cm liquid H 2 and D 2 targets Luminosity > 10 38 /cm 2 /s solid angle > 200 msr count at 100 kHz on-line pion rejection of 10 2 to 10 3 Goal: Form a collaboration, start real design and simulations, and make pitch to US community at the next nuclear physics Long Range Plan (2007)

28. Thomas Jefferson National Accelerator Facility Page 28 SPIN2006, October 7, 2006, 28 Beamline Instrumentation Preshower Calorimeter Forward Drift Chambers Inner Cerenkov (HTCC) Superconducting Torus Magnet Central Detector Forward Calorimeter Forward Time-of-Flight Detectors * Reused detectors from CLAS Forward Cerenkov (LTCC) Inner Calorimeter Hall B - CLAS12 New TOF Layer

29. Thomas Jefferson National Accelerator Facility Page 29 SPIN2006, October 7, 2006, 29 Hall C - Side View of SHMS Design

30. Thomas Jefferson National Accelerator Facility Page 30 SPIN2006, October 7, 2006, 30 SHMS/HMS: Detector Systems Option: Replace Cherenkov with Focal Plane Polarimeter (for  /e at high E’ only, otherwise vacuum) Space for aerogel, etc. Quartz Hodoscope

31. Thomas Jefferson National Accelerator Facility Page 31 SPIN2006, October 7, 2006, 31 SHMS/HMS: Detector Systems Option: Replace Cherenkov with Focal Plane Polarimeter, with a similar option in SHMS! (Q 2 > 12 GeV 2 ) (for  /e at high E’ only, otherwise vacuum)

32. Thomas Jefferson National Accelerator Facility Page 32 SPIN2006, October 7, 2006, 32 flux photon energy (GeV) 12 GeV electron beam This technique provides requisite energy, flux and linear polarization collimated Incoherent & coherent spectrum tagged (0.1% resolution) 40% polarization in peak electrons in photons out spectrometer (two magnets) diamond crystal Hall D - Coherent Bremsstrahlung

33. Thomas Jefferson National Accelerator Facility Page 33 SPIN2006, October 7, 2006, 33 Tagger Spectrometer (Upstream) Hermetic detection of charged and neutral particles Hall D - GluEx Detector

34. Thomas Jefferson National Accelerator Facility Page 34 SPIN2006, October 7, 2006, 34 12 GeV Upgrade: Project Schedule 2004-2005 Conceptual Design (CDR) 2004-2008 Research and Development (R&D) 2006 Advanced Conceptual Design (ACD) 2007-2009 Project Engineering & Design (PED) 2008-2009 Long Lead Procurement 2009-2013 Construction 2012-2014 Pre-Ops (beam commissioning) Critical Decision (CD)Presented at IPR CD-0 Mission Need2QFY04 (Actual) CD-1 Preliminary Baseline Range2QFY06 (Actual) CD-2A/3A Construction and Performance Baseline of Long Lead Items 4QFY07 CD-2B Performance Baseline4QFY08 CD-3B Start of Construction2QFY09 CD-4 Start of Operations1QFY15 JLab Upgrade only present construction project in DOE-NP First 12 GeV beam expected in ~2012 However, plans for next upgrade already being developed now

35. Thomas Jefferson National Accelerator Facility Page 35 SPIN2006, October 7, 2006, 35 Why Electron-Ion Collider? Polarized DIS and e-A physics: in past only in fixed-target mode Collider geometry allows complete reconstruction of final state Better angular resolution between beam and target fragments Lepton probe provides precision but requires high luminosity to be effective High E cm  large range of x, Q 2 Q max 2 = E CM 2 x x range: valence, sea quarks, glue Q 2 range: utilize evolution equations of QCD High polarization of lepton and nucleon a requisite

36. Thomas Jefferson National Accelerator Facility Page 36 SPIN2006, October 7, 2006, 36 Ring-Ring Concept Use present CEBAF as injector to electron storage ring Add light-ion complex Linac 200 MeV Ion Collider Ring Pre-Booster 3 GeV/c C≈75-100 m Ion Large Booster 20 GeV (Electron Storage Ring) spin

37. Thomas Jefferson National Accelerator Facility Page 37 SPIN2006, October 7, 2006, 37 Achieving the Luminosity of ELIC For 150 GeV protons on 7 GeV electrons, L~ 8 x 10 34 cm -2 s -1 is compatible with realistic Interaction Region design. Beam Physics Issues High energy electron cooling Beam – beam interaction between electron and ion beams (  i ~ 0.01 per IP; 0.025 is presently utilized in Tevatron) Interaction Region  High bunch collision frequency (f = 1.5 GHz)  Short ion bunches (  z ~ 5 mm)  Very strong focus (  * ~ 5 mm)  Crab crossing

38. Thomas Jefferson National Accelerator Facility Page 38 SPIN2006, October 7, 2006, 38 Polarization of Electrons/Positrons Spin injected vertical in arcs (using Wien filter) Self-polarization in arcs to support injected polarization Spin rotators matched with the cross bends of Interaction Points Electrons at 200 MeV yield unpolarized positron accumulation of ~100 mA/min ½ hr to accumulate 3 A of positron current Sokolov-Ternov polarization for positrons (2 hrs at 7 GeV – varies as E -5 ) spin rotator collision point spin rotator with 90º solenoid snake collision point spin rotator with 90º solenoid snake

39. Thomas Jefferson National Accelerator Facility Page 39 SPIN2006, October 7, 2006, 39 Summary of Future Spin Physics at JLab The Upgrade to 12 GeV at JLab is well underway (preparing for CD-2 review) It will allow ground-breaking studies of  the structure of the nucleon  exotic mesons and the origin of confinement  the QCD basis of nuclear structure  the Standard Model at the multi-TeV scale  All requiring the use of highly polarized beams (and/or targets) The schedule of LQCD calculations at JLab is commensurate with the physics goals of the 12 GeV Upgrade Design studies at JLab have led to a promising design of an electron-ion collider  a luminosity of up to ~10 35 cm -2 s -1  at a center-of-mass energy between 20 and 65 GeV  for collisions between polarized electrons/positrons and light ions (A≤40)