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TMD Physics with SoLID -SIDIS

TMD Physics with SoLID -SIDIS. Xin Qian Caltech For the SoLID -Spin Collaboration. d 2 k T dr z. d 3 r. TMD PDFs f 1 u (x,k T ), .. h 1 u (x,k T ) ‏. GPDs/IPDs. A Unified Picture of Nucleon Structure. 6D Des. W p u (x,k T , r ) Wigner distributions. 3D imaging. dx &

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TMD Physics with SoLID -SIDIS

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  1. TMD Physics with SoLID-SIDIS XinQian Caltech For the SoLID-Spin Collaboration Hall A Collaboration Meeting

  2. d2kT drz d3r TMD PDFs f1u(x,kT), .. h1u(x,kT)‏ GPDs/IPDs A Unified Picture of Nucleon Structure 6D Des. 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 X. Ji PRL 91 (03)‏

  3. J q Nucleon Spin Structure Nucleon’s spin Ji’s Sum Rule • Understand Nucleon Spin in terms of quarks and gluons (QCD) • Small contribution from quarks and gluons’ intrinsic spin ~30% from data “spin crisis” • Orbital angular momentum is important! • Parton transverse motion + Spin-orbit correlations Hall A Collaboration Meeting

  4. TMD f1u(x,kT)‏ Transverse Momentum Dependent PDFs Longitudinal Direction z Transverse Plane x-y Hall A Collaboration Meeting

  5. Nucleon Spin Leading-Twist TMD PDFs Quark Spin Very well known h1= Boer-Mulders f1 = Reasonably known h1L= Worm Gear (Kotzinian-Mulders) Helicity g1 = h1= Transversity f1T= g1T= h1T= Sivers Worm Gear Pretzelosity Spin-orbital (trans. mom.) correlation is important! Hall A Collaboration Meeting

  6. Access TMDs through Semi-Inclusive DIS f1 = Unpolarized Boer-Mulder h1= h1L= Transversity h1T = Polarized Target Sivers f1T= Pretzelosity h1T= Polarized Beam and Target g1 = g1T= SL, ST: Target Polarization; le: Beam Polarization Hall A Collaboration Meeting

  7. Semi-Inclusive DIS DXs ~ PDF X FF h tags struck quark’s flavor, spin and transverse momentum Fragmentation function (FF)‏ h Parton distribution function (PDF)‏ Current Fragmentation Hall A Collaboration Meeting

  8. Hall A Polarized 3He Target S S’ D ~90% ~1.5% ~8% High luminosity: L(n) = 1036 cm-2 s-120 mins spin flip with K/Rb hybrid cells ~55% in beam polarization 1o atm3He Some N2, Rb, K Oven 230 oC Polarized Laser 795 nm F = 3” Pumping Chamber 25 G Holding Field 40 cm Target Chamber Hall A Collaboration Meeting

  9. Collins effect • Access to transversity • Transversity links quak’s spin tonucleon spin • Collins FF links quark’s spin to hadron transverse momentum • Artru model • Based on LUND fragmentation picture. Hall A Collaboration Meeting

  10. Rich Physics in TMDs (Sivers Function) • Correlation between nucleon spin with quark orbital angular momentum Burkhardt : chromodynamic lensing Important test for Factorization Final-State-Interaction Hall A Collaboration Meeting

  11. Results on Neutron • Sizable Collins π+ asymmetries at x=0.34? • Sign of violation of Soffer’s inequality? • Data are limited by stat Needs more precise data! • Negative Siversπ+ Asymmetry • Consistent with HERMES/COMPASS • Independent demonstration of negative d quark Sivers function. X. Qian PRL 107 072003 (2011) Model (fitting) uncertainties shown in blue band Radiative correction, diffractive ρ production, and finalize systematic uncertainties before submission Hall A Collaboration Meeting

  12. Double Spin Asymmetry: g1T • Leading twist TMD PDFs • T-even, Chiral-even • Dominated by real part ofinterference between L=0 (S) and L=1 (P) states • Imaginary part -> Sivers effect • First TMDs in Lattice calculation • arXiv:0908.1283 [hep-lat],Europhys.Lett.88:61001,2009 • arXiv:1011.1213 [hep-lat] , Phys.Rev.D83:094507,2011 Worm Gear g1T (1) n e’ S-P int. e TOT X g1T= P-D int. π Beam Helicity Light-Cone CQM by B. Pasquini B.P., Cazzaniga, Boffi, PRD78, 2008 Target Spin Hall A Collaboration Meeting

  13. Extract Neutron ALT J. Huang et al. PRL 108, 052001 (2012) • Neutron π+ data is sensitive to d , π- data also sensitive to u • Consist w/ model in signs, suggest larger asymmetry Hall A Collaboration Meeting

  14. SoLID-Spin: SIDIS on 3He/Proton @ 11 GeV E12-10-006:Single Spin Asymmetry on Transverse 3He @ 90 days E12-11-007:Single and Double Spin Asymmetry on 3He @ 35 days E12-11-108:Single and Double Spin Asymmetries on Transverse Proton @ 120 days White paper: Eur. Phys. J. Plus (2011) 126:2 • Key of SoLID-Spin program: • Large Acceptance + High Luminosity4-D mapping of asymmetriesTensor charge, TMDs … • Lattice QCD, QCD • Dynamics, Models Hall A Collaboration Meeting

  15. SoLID Setup for SIDIS • Tracking: GEM Tracker. • Shared R&D with Super BigBite • Electron Identification: • Large angle • E&M calorimeter • Forward angle • E&M calorimeter • Light gas Cerenkov • Pion identification: • Heavy Gas Cerenkov • TOF (Multi-gap Resistive Plate Chamber) • Fast pipeline DAQ (Similar to Hall D) • Polarized 3He and Polarized NH3 targets Hall A Collaboration Meeting

  16. Projections on Collins/Sivers Asymmetry (90 Days) Collins 1/48 bins 4-D Mapping of Asymmetries Tensor Charge Expected Improvement of Sivers Function From A. Prokudin Sivers 1/48 bins Hall A Collaboration Meeting

  17. Requirement of SIDIS • Kinematics Coverage: • 0.05 ~ 0.6 in x (valence) • 0.3 ~ 0.7 in z (factorization region) • PT up to ~ 1 GeV (TMD Physics) • Fixed target  Q2 coverage 1-8 GeV2 (~ 2 GeV2 in ΔQ2 at fixed x) • Luminoisity: • Unpolarized ~ 1037 N/cm2/s • Polarized 3He Target: • ~ 60% higher polarization • Fast spin flip (<20 mins) • Electron PID: • <1% Pion contamination (asymmetry point of view) • Pion PID: • <1% Kaons and Protons • <1% electron contamination • Optics of Reconstruction: • < a few % in δP/P. • < 1 mr in polar angle. • < 10 mr in azimuthal angle • ~ 1-2 cm vertex resolution • Similar precision required. • A factor of 2-3 better already achieved in MC. • DAQ: • ~ 3kHz Physics Coincidence • ~ 100 kHz Single electron • ~ 60 kHz Coincidence • Limits: 300 MB/s to tape. Hall A Collaboration Meeting

  18. Bright Future for TMDs • Electron Ion Collider: • The Next QCD Frontier - Understanding the glue that binds us all (arXiv:1212.1701) • Stage-I EIC • Proton Spin • The motion of quarks and gluons in the proton • Sea quark TMDs Gluon Sivers? • Test Collins-Soper Evolution at large x • The tomographic images of the proton • QCD matter at an extreme gluon density • Quark hadronization Hall A Collaboration Meeting

  19. Impact of Jlab12 + EIC Hall A Collaboration Meeting

  20. Summary • TMD physics plays a crucial role in understanding Nucleon Spin/Quark OAM • Neutron SSA and DSA has been measured for the first time in Hall A • TMD physics with SoLID-SIDIS • u/d tensor charge measurements • 4-D measurements in the valence region • Natural extensions at future EIC Hall A Collaboration Meeting

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