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TMD Study at JLab : Results and Future

TMD Study at JLab : Results and Future. J. P. Chen , Jefferson Lab PacificSPIN-13, Jinan, China, October 28-31, 2013. TMDs with 6 GeV JLab : Exploration Results from Hall C: P T dependence of unpolarized flavor PDFs Results from Hall B (CLAS6)

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TMD Study at JLab : Results and Future

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  1. TMD Study at JLab: Results and Future J. P. Chen , Jefferson Lab PacificSPIN-13, Jinan, China, October 28-31, 2013 • TMDs with 6 GeVJLab: Exploration • Results from Hall C: PT dependence of unpolarized flavor PDFs • Results from Hall B (CLAS6) • PT dependence of spin asymmetry A1 • SSA with longitudinal target or beam • Recent and preliminary results Hall A (transversely Polarized 3He (n)) • Collins/Sivers/Worm-gear asymmetries on pionsand Kaons • Inclusive hadron and electron SSA • JLab 12 GeV Plan for TMD study: Precision Multi-d Mapping • SoLID Program on TMDs • TMD program in Hall B (CLAS12) and C

  2. Jefferson Lab at a Glance • CEBAF • High-intensity electron accelerator based onCW SRFtechnology • Emax = 6 GeV • Imax = 200 mA • Polmax = 85% 12 GeV • ~ 1400 Active Users • ~ 800 FTEs • 178 Completed Experiments @ 6 GeV • Produces ~1/3 of US PhDs in Nuclear Physics C A B A C B

  3. Unified View of Nucleon Structure d2kT d2rT TMD PDFs f1u(x,kT), .. h1u(x,kT)‏ GPDs/IPDs 5D Dist. Wpu(x,kT,r ) Wigner distributions 3D imaging dx & Fourier Transformation d2kT d2rT Form Factors GE(Q2), GM(Q2)‏ PDFs f1u(x), .. h1u(x)‏ 1D

  4. Leading-Twist TMD PDFs Nucleon Spin Quark Spin h1= Boer-Mulders f1 = h1L= Worm Gear Helicity g1 = h1= Transversity f1T= g1T= h1T= Sivers Worm Gear Pretzelosity : Probed with transversely pol target HERMES, COMPASS, JLab E06-010

  5. Tool: Semi-inclusive DIS (SIDIS) • Gold mine for TMDs • Access all eight leading-twist TMDs through spin-comb. & azimuthal-modulations • Tagging quark flavor/kinematics Scattering Plane

  6. Unpolarized TMDs Test x-z Factorization Flavor PT Dependence JLab Hall C SIDIS Results

  7. From Form Factors to Transverse Densities up quark down quark by by bx bx

  8. Unpolarized TMD: Flavor PT Dependence? up quark down quark ky ky kx kx A. Bacchetta, Seminar @ Jlab, arXiv1309.3507 (2013)

  9. Flavor PT Dependence from Theory • Chiral quark-soliton model (Schweitzer, Strikman, Weiss, JHEP, 1301 (2013) •  sea wider tail than valanee f1u/f1d kT • Flagmentation model, Matevosyan, Bentz, Cloet, Thomas, PRD85 (2012) • unfavoredpion and Kaon wider than favored pion

  10. Hall C Results: Flavor PT Dependence (md)2 (m-)2 (m+)2 (mu)2 C

  11. Results: from JLab Hall B (CLAS6) • PT Dependence of A1 • SSA in Longitudinal Target • SSA in Longitudinal Beam • (plots courtesy of HarutAvagyan)

  12. Lattice A1 PT-dependence arXiv:1003.4549 A1 PT B.Musch et al arXiv:1011.1213 CLAS data suggests that width of g1 is less than the width of f1

  13. Kotzinian-Mulders Asymmetries HERMES <kx> = −60(5) MeV for down quarks <kx> = 16(5) MeV for up quarks CLAS (5days) B. Pasquini hep-ph/0806.2298 B.Musch arXiv:0907.2381 KM-TMD unique (no analogin GPDs)

  14. SSA for longitudinally polarized target hep-ex/0104005 Kotzinian et al (1999) Efremov et al (2001) Zhun Lu et al (2013) CLAS PRELIMINARY sinfasymmetry for long.pol. target are comparable for p0& p+while p- SSA seem to have an opposite sign indicating significant Collins type contribution.

  15. SSA for longitudinally polarized beam The force on a quark polarized in the x-direction with kT in the y-direction right after scattering Burkardt (2008),Qiu(2011) ALUCLAS @4.3 GeV (2003) Efremov et al (2003) W. Gohn W. Mao, Z. Lu (arXiv:1210.4790) CLAS 5.7 GeV(p0) CLAS 5.5 GeV Sivers type contribution may dominate the p0 SSAs Collins type contribution seem to dominate the p-SSA

  16. Single Spin Asymmetries with A Transversely Polarized 3He (n) JLab Hall A E06-010 Published and Preliminary Results From SIDIS and Inclusive Reactions

  17. SIDIS: Separation of Collins, Sivers and pretzelocity effects through angular dependence

  18. E06‑010 Experiment 7 PhD Thesis Students (graduated) + 2 new students Luminosity Monitor • First measurement on n (3He) • Transversely Polarized 3He Target • Polarized Electron Beam, 5.9 GeV • BigBite at 30º as Electron Arm • Pe = 0.7 ~ 2.2 GeV/c • HRSL at 16º as Hadron Arm • Ph = 2.35 GeV/c • Excellent PID for p/K/p Beam Polarimetry (Møller + Compton)

  19. E06-010 collaboration, X. Qian at al., PRL 107:072003(2011) 3He (n) Target Single-Spin Asymmetry in SIDIS neutron Collins SSA small Non-zero at highest x for p+ neutron Sivers SSA: negative for π+, Agree with Torino Fit Blue band: model (fitting) uncertainties Red band: other systematic uncertainties

  20. Asymmetry ALT Result J. Huang et al., PRL. 108, 052001 (2012). Worm-Gear • neutron ALT : Positive for p- • Consist w/ model in signs, suggest larger asymmetry Trans helicity • Dominated by L=0 (S) and L=1 (P) interference To leading twist:

  21. Pretzelosity Results on Neutron • Analysis by Y. Zhang (Lanzhou) and X. Qian (Caltech) Extracted Pretzelosity Asymmetries, For both p+ and p-, consistent with zero within uncertainties. Preliminary Results In models, directly related to OAM, L=0 and L=2 interference

  22. E06-010: Inclusive Hadron SSA (AN) Analysis by K, Allada (JLab), Y. Zhao (USTC) • Clear non-zero vertical target SSA • Opposite sign forp+andp- • Large for K+ vertical target Preliminary

  23. E06-010: Inclusive Hadron SSA (AN) • Clear non-zero target SSA • Opposite sign forp+andp- • AN at low pT not very well • understood • Results consistent with predictions based on Sivers mechanism (valid at high pT) Preliminary vertical target Preliminary

  24. Inclusive Target Single Spin Asymmetry: DIS θ 3He e- • Unpolarizede- beam incident on 3He target polarized normal to the • electron scattering plane. • However, Ay=0 at Born level, •  sensitive to physics at order α2; two-photon exchange. • In DIS case: related to integral of Sivers • Physics Importance discussed in A. Metz’s paper

  25. Inclusive Target Single-Spin Asymmetry • Analysis by J. Katech(W&M), X. Qian (Caltech) Extracted neutron SSA from 3He(e,e’) Vertically polarized target • Results show 2-photon effects • Consistent with A. Metz’s prediction: 2-photon interact with 2 quarks and q-g-q correlator from Torino fit for Sivers (solid black) • Disagree with predictions based on KQW q-g-q correlator(red-dashed) • Disagree with predictions based on 2-photon interact with 1 quark (blue dashed)

  26. Future: TMD study 12 GeVJLab Precision Study of TMDs In the Valence Quark Region

  27. U L T Multi-Halls SIDIS Program q N Hall C/SHMS L-T studies, precise p+/p-ratios Hall A/SBS High x - Q2, 2-3D Hall B/CLAS12 General survey, medium luminosity U Hall A/SOLID High Lumi and acceptance – 4D L T H2 D2 3He, NH3 H2/D2, NH3/ND3, HD

  28. SoLID for SIDIS/PVDIS with 12 GeVJLab • Exciting physics program: • Five approved experiments: • three SIDIS “A rated”, one PVDIS “A rated”, one J/Psi “A- rated” • International collaboration: eight countries and 50+ institutions • GEMs for tracking • Cherenkov and EM Calorimeter for electron PID • Heavy Gas Cherenkov and MRPC (TOF) for pion PID • CLEOII Magnet (official) • Draft pCDR just completed

  29. E12-10-006/E12-11-108, Both Approved with “A” Rating Mapping of Collins(Sivers) Asymmetries with SoLID • Both p+ and p- • Precision Map in region x(0.05-0.65) z(0.3-0.7) Q2(1-8) PT(0-1.6) • <10% d quark tensor charge Collins (Sivers) Asymmetries

  30. Expected Improvement: Sivers Function f1T= • Significant Improvement in the valence quark (high-x) region • Illustrated in a model fit (from A. Prokudin)

  31. E12-11-107: Worm-gear functions (“A’ rating: ) • Dominated by real part ofinterference between L=0 (S) and L=1 (P) states • No GPD correspondence • Lattice QCD -> Dipole Shift in mom. space. • Model Calculations -> h1L =? -g1T. h1L= Longi-transversity Trans-helicity Center of points: g1T=

  32. Summary on SoLID TMD Program Unprecedented precision 4-d mapping of SSA Collins, Sivers, Pretzelosityand Worm-Gear Both polarized 3He (n) and polarized proton with SoLID Three “A” rated experiments approved. One LOI on di-hadron. Study factorization with x and z-dependences Study PT dependence Combining with the world data extract transversity and fragmentation functions for both u and d quarks determine tensor charge study TMDs for both valence and sea quarks learn quark orbital motion and quark orbital angular momentum study Q2 evolution Global efforts (experimentalists and theorists), global analysis much better understanding of multi-d nucleon structure and QCD Welcome new collaborators

  33. Summary • Nucleon Spin and TMD study have been exciting and fruitful • Recent and Preliminary Results from JLab with transversely polarized targets: g2, TMDs • JLab 12 GeV Planned SoLID program with JLab12 Precision 4-d mapping of TMD asymmetries • Longer-term future: EIC in US, China and Europe Exciting new opportunities Precision experimental data + development in theory for Nucleon TMDs +… • lead to breakthrough in understanding QCD?

  34. Backup Slides

  35. Polarized 3He Target Luminosity Monitor • High Luminosity polarize target: L(n) = 1036 cm-2 s-1(achieved), 1037 cm-2 s-1 (R&D) • Compact size: No cryogenic support needed • Proton dilution measured experimentally ~90% ~1.5% ~8% 3He Cell Beam Polarimetry Beam

  36. Performance of 3He Target • High luminosity: L(n) = 1036 cm-2 s-1 • Record high 50-65% polarization in beam with automatic spin flip / 20min • <P> = 55.4% ± 0.4% (stat. per spin state) ± 2.7 % (sys.)

  37. X. Qian at al., PRL 107:072003(2011) E06-010 3He Target Single-Spin Asymmetry in SIDIS 3He Collins SSA small Non-zero at highest x for p+ 3He Sivers SSA: negative for π+, Blue band: model (fitting) uncertainties Red band: other systematic uncertainties

  38. Asymmetry ALT Result J. Huang et al., PRL. 108, 052001 (2012). • 3He ALT : Positive for p- Worm-Gear. To leading twist:

  39. Inclusive Hadron Electroproduction e + N↑h + X (h = p, K, p) pT • Why a non-zero AN isinteresting? • Analogues to AN in collision • Simpler than due to only one quark channel • Same transverse spin effects as SIDIS and p-p collisions (Sivers, Collins, twist-3) • Clean test TMD formalism (at large pT~ 1 GeV or more) • To help understand mechanism behind large AN in in the TMD framework

  40. Transverse SSA in Inclusive Hadron Preliminary p- p+ False Asymmetry • Target spin flip every 20 minutes • Acceptance effects cancels • Overall systematic check with AN at ϕS= 0 • False asymmetry < 0.1%

  41. JLab 12 GeV Upgrade The completion of the 12 GeV Upgrade of CEBAF was ranked the highest priority in the 2007 NSAC Long Range Plan. Add 5 cryomodules New Hall 20 cryomodules CHL-2 Add arc 20 cryomodules Add 5 cryomodules • Enhanced capabilities in existing Halls • Increase of Luminosity1035 - ~1039 cm-2s-1 Maintain capability to deliver lower pass beam energies : 2.2, 4.4, 6.6,….

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

  43. Map Collins and Sivers asymmetries in 4-D (x, z, Q2, PT)

  44. New : LOI – Dihadron in DIS on 3He • Access transversity in transversely polarized neutron target through π+ π- di-hadron production • Run simultaneously with SIDIS 3He (e,e’π±)X • Systematical check of two approaches to access h1 Asymmetry projection for one M-z bin

  45. The TMD simulation: Projections for SIDIS Asymmetry π+ EIC@HIAF reach high precision similar to SoLID at lower x, higher Q2 region HiayanGao (Duke) Green (Blue) Points: SoLID projections for polarized NH3(3He/n) target Luminosity: 1035 (1036) (1/cm2/s); Time: 120 (90) days Black points: EIC@HIAF projections for 3 GeV e and 12 GeV p Luminosity: 4 x 1032 /cm2/s; Time: 200 days

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