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Future Spin Physics at JLab 12 GeV and Beyond Kees de Jager Jefferson Lab SPIN2006 Kyoto

Future Spin Physics at JLab 12 GeV and Beyond Kees de Jager Jefferson Lab SPIN2006 Kyoto October 2-7, 2006. Highlights of the 12 GeV Program. Revolutionize Our Knowledge of Spin and Flavor Dependence of PDFS in the Valence Region

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Future Spin Physics at JLab 12 GeV and Beyond Kees de Jager Jefferson Lab SPIN2006 Kyoto

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  1. Future Spin Physics at JLab 12 GeV and Beyond Kees de Jager Jefferson Lab SPIN2006 Kyoto October 2-7, 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 (2C2u-C2d) electron-quark couplings • Determination of sin2w to within 0.00025

  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. 12 GeV : Unambiguous Flavor Structure x —> 1 After 35 years: Miserable Lack of Knowledge of Valence d-Quarks Hall A at 11 GeV with BigBite pQCD di-quark correlations

  5. Unambiguous Resolution of Valence Spin A1p at 11 GeV A1n at 11 GeV

  6. Complements Spin-Flavor Dependence at RHIC At RHIC with W production At JLab with 12 GeV upgrade 12 Stops at x≈0.5 AND needs valence d(x)

  7. 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

  8. Experiments at 11 GeV will extend data Neutron Proton Electric To 14 GeV2 To 5 GeV2 Magnetic To 15 GeV2

  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. The Next Generation of Proton Structure Experiments GPDs The fully-correlated Quark distribution in both coordinate and momentum space DIS longitudinal quark distribution in momentum space Elastic Scattering transverse quark distribution in Coordinate space

  11. Generalized Parton Distributions (GPDs): New Insight into Hadron Structure Quark angular momentum (Ji’s sum rule) [ ] 1 1 1 ò = - JG = x + x q q q J xdx H ( x , , 0 ) E ( x , , 0 ) 2 2 - 1 X. Ji, Phy.Rev.Lett.78,610(1997) Flavor separation through Deeply Virtual Meson Production e.g.

  12. Access GPDs through x-section and asymmetries DIS measures at x=0 Quark distribution q(x) Accessed by beam/target spin asymmetry -q(-x) t = 0 Accessed by cross sections Flavor separation through DVMP

  13. Exclusive 0 with transverse target A ~ (2Hu +Hd) B ~ (2Eu + Ed) r0 Asymmetry depends linearly on the GPD E, which enters Ji’s sum rule L=1035cm-2s-1 2000hrs K. Goeke, M.V. Polyakov, M. Vanderhaeghen, 2001 sL dominance DQ2 =1 -t = 0.5GeV2Dt = 0.2 AUT xB

  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. Gluonic Excitations and the Origin of Confinement Hybrid mesons 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 Jpc = 1-+ ~1 GeV mass difference Normal mesons An excited flux tube gives rise to hybrid mesons with conventional and exotic quantum numbers JPC

  16. Glueballs and hybrid mesons Colin Morningstar: Gluonic Excitations workshop, 2003 (JLab)

  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 JPC • Identifying JPC 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 Final states include photons and charged particles and require particle identification Hermetic detector with large acceptance for charged and neutral particles 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

  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. The EMC Effect: Nuclear PDFs Classic Illustration: The EMC effect • 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? J. Ashman et al., Z. Phys. C57, 211 (1993) J. Gomez et al., Phys. Rev. D49, 4348 (1994)

  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 • g1A(x) “Polarized EMC effect” – influence of nucleus on spin • Flavor-tagged polarized structure functions uA(xA) and dA(xA) • x dependence of axial-vector current in nuclei (can study via parity violation) • Nucleon-tagged structure functions from 2H and 3He • Study x-dependence of exclusive channels on light nuclei, sum up to EMC

  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. PV DIS at 11 GeV with an LD2 target For an isoscalar target like 2H, structure functions largely cancel in the ratio: (Q2 >> 1 GeV2 , W2 >> 4 GeV2, x ~ 0.3-0.5) • Must measure APV to 0.5% fractional accuracy • Luminosity and beam quality available at JLab e- e- * Z* X N • 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

  23. Precision High-x Physics with PV DIS For hydrogen 1H: 1% APV measurements Longstanding issue: d/u as x1 • Allows d/u measurement on a single proton! Charge Symmetry Violation (CSV) at High x: clean observation possible 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% APV measurement at x ~ 0.75 Global fits allow 3 times larger effects

  24. Future Possibilities (Purely Leptonic) JLab e2e @ 12 GeV Møller at 11 GeV at Jlab sin2W to ± 0.00025! ee ~ 25 TeV reach! Higher luminosity and acceptance 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 -e in reactor can test neutrino coupling: sin2W to ± 0.002 e.g. Z’ reach ~ 2.5 TeV • Comparable to single Z pole measurement: shed light on disagreement • Best low energy measurement until ILC or -Factory • Could be launched ~ 2015

  25. Upgrade magnets and power supplies CHL-2 Enhance equipment in existing halls Add new hall 12 11 6 GeV CEBAF

  26. HALL A - 12 GeV Upgrade Summary Infrastructure for Large Installations

  27. A Vision for Precision PV DIS Physics • solid angle > 200 msr • count at 100 kHz • on-line pion rejection of 102 to 103 • Hydrogen and Deuterium targets • Better than 2% errors • It is unlikely that any effects are larger than 10% • x-range 0.25-0.75 • W2 well over 4 GeV2 • Q2 range a factor of 2 for each x • (Except x~0.75) • Moderate running times • CW 90 µA at 11 GeV • 40 cm liquid H2 and D2 targets • Luminosity > 1038/cm2/s 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. Hall B - CLAS12 Forward Calorimeter Preshower Calorimeter Forward Cerenkov (LTCC) Forward Time-of-Flight Detectors Forward Drift Chambers Superconducting Torus Magnet New TOF Layer Inner Cerenkov (HTCC) Central Detector Beamline Instrumentation * Reused detectors from CLAS Inner Calorimeter

  29. Hall C - Side View of SHMS Design

  30. SHMS/HMS: Detector Systems Option: Replace Cherenkov with Focal Plane Polarimeter Quartz Hodoscope Space for aerogel, etc. (for p/e at high E’ only, otherwise vacuum)

  31. SHMS/HMS: Detector Systems Option: Replace Cherenkov with Focal Plane Polarimeter, with a similar option in SHMS! (Q2 > 12 GeV2) (for p/e at high E’ only, otherwise vacuum)

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

  33. Hall D - GluEx Detector Hermetic detection of charged and neutral particles Tagger Spectrometer (Upstream)

  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) • 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. 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 Ecm  large range of x, Q2Qmax2= ECM2•x x range: valence, sea quarks, glue Q2 range: utilize evolution equations of QCD • High polarization of lepton and nucleon a requisite

  36. Ion Collider Ring spin Ring-Ring Concept Linac 200 MeV Ion Large Booster 20 GeV (Electron Storage Ring) Pre-Booster 3 GeV/c C≈75-100 m Use present CEBAF as injector to electron storage ring Add light-ion complex

  37. Achieving the Luminosity of ELIC For 150 GeV protons on 7 GeV electrons, L~ 8 x 1034 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. Polarization of Electrons/Positrons spin rotator spin rotator spin rotator with 90º solenoid snake collision point collision point collision point collision point spin rotator with 90º solenoid snake spin rotator spin rotator • 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)

  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 ~1035 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)

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