TMDs and PVDIS: JLab 6 GeV results and 12 GeV Plan J. P. Chen, Jefferson Lab APFB2014, Hahndorf, Australia, April 7-11, 2014  TMDs with 6 GeV JLab: Exploration Recent and new results with a transversely Polarized 3 He (n) Collins/Sivers/Worm-gear asymmetries on pions and Kaons Inclusive hadron and electron SSA  JLab 12 GeV Plan for TMD study: Precision Multi-d Mapping SoLID Program on TMDs  PVDIS with 6 GeV JLab: New Results  12 GeV plan for PVDIS: SoLID Program

JLab 12 GeV Upgrade Maintain capability to deliver lower pass beam energies : 2.2, 4.4, 6.6,….  Enhanced capabilities in existing Halls  Increase of Luminosity ~10 39 cm -2 s -1  Enhanced capabilities in existing Halls  Increase of 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

W p u (x,k T,r ) Wigner distributions d2kTd2kT PDFs f 1 u (x),.. h 1 u (x)‏ GPDs/IPDs d2kTd2kT d2rTd2rT 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

Leading-Twist TMD PDFs f 1 = f 1T  = Sivers Helicity g 1 = h1 =h1 = Transversity h1 =h1 =Boer-Mulders h 1T  = Pretzelosity g 1T = Worm Gear h 1L  = Worm Gear : Probed with transversely pol target HERMES, COMPASS, JLab E Nucleon Spin Quark Spin

 Gold mine for TMDs  Access all eight leading-twist TMDs through spin-comb. & azimuthal- modulations  Tagging quark flavor/kinematics

Status of Transverse Spin/TMD Study Large single spin asymmetry in pp->  X (Fermi, RHIC-spin) Collins Asymmetries - sizable for the proton (HERMES and COMPASS) large at high x,  - and  has opposite sign  unfavored Collins fragmentation as large as favored (opposite sign)? - consistent with 0 for the deuteron (COMPASS) Sivers Asymmetries - non-zero for  + from proton (HERMES), new COMPASS data - large for K + ? Collins Fragmentation from Belle Global Fits/models: Anselmino et al., Yuan et al., Pasquini et al., Ma et al., … Very active theoretical and experimental efforts JLab (6 GeV and 12 GeV), RHIC-spin, Belle, FAIR, J-PARC, EIC, … First neutron measurement from Hall A 6 GeV (E06-010) SoLID with polarized p and n( 3 He) at JLab 12 GeV Unprecedented precision with high luminosity and large acceptance

Single Spin Asymmetries with A Transversely Polarized 3 He (n) JLab Hall A E Published and Preliminary Results From SIDIS and Inclusive Reactions

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

E06 ‑ 010 Experiment First measurement on n ( 3 He) Transversely Polarized 3 He Target Polarized Electron Beam, 5.9 GeV BigBite at 30º as Electron Arm – P e = 0.7 ~ 2.2 GeV/c HRS L at 16º as Hadron Arm – P h = 2.35 GeV/c – Excellent PID for  /K/p 9 Beam Polarimetry (Møller + Compton) Luminosity Monitor Spokespersons: J. P. Chen, E. Cisbani, H. Gao, X. Jiang and J. C. Peng 7 PhD Thesis Students (graduated) + 2 new students

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

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

Pretzelosity Results on Neutron In models, directly related to OAM, L=0 and L=2 interference Analysis by Y. Zhang (Lanzhou) and X. Qian (Caltech) submitted to PRC, arXiv:

E06-010: Inclusive Hadron SSA (A N ) Clear non-zero vertical target SSA Opposite sign for   and   Large for K + vertical target Analysis by K, Allada (JLab), Y. Zhao (USTC), PRC 89, (2014)

E06-010: Inclusive Hadron SSA (A N ) Clear non-zero target SSA Opposite sign for   and     A N at low p T not very well understood Results consistent with predictions based on Sivers mechanism (valid at high p T ) vertical target

Inclusive Target Single Spin Asymmetry: DIS 3 He θ e-e- Unpolarized e - beam incident on 3 He target polarized normal to the electron scattering plane. However, A y =0 at Born level,  sensitive to physics at order α 2 ; two-photon exchange. In DIS case: related to integral of Sivers Physics Importance discussed in A. Metz’s paper

Inclusive Target Single-Spin Asymmetry Extracted neutron SSA from 3 He(e,e’) 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) Analysis by J. Katech(W&M), X. Qian (Caltech), submitted to PRL, arXiv:

Future: TMD study 12 GeV JLab Precision Study of TMDs In the Valence Quark Region

JLab 12 GeV Era: Precision Study of TMDs From exploration to precision study with 12 GeV JLab Transversity: fundamental PDFs, tensor charge TMDs: 3-d momentum structure of the nucleon  Quark orbital angular momentum Multi-dimensional mapping of TMDs 4-d (x,z,P ┴,Q 2 ) Multi-facilities, global effort Precision  high statistics high luminosity and large acceptance

SoLID for SIDIS/PVDIS with 12 GeV JLab Exciting physics program: Five approved experiments: three SIDIS “A rated”, one PVDIS “A rated”, one J/Psi “A- rated” International collaboration: nine 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) pCDR just completed

Mapping of Collins(Sivers) Asymmetries with SoLID E (n) Spokespersons: J. P. Chen, H. Gao, X. Jiang, J. C. Peng and X. Qian E (p): K. Allada, J. P. Chen, H. Gao, X. Li and Z. E. Meziani Both Approved with “A” Rating Both  + and  - Precision Map in region x( ) z( ) Q 2 (1-8) P T (0-1.6) <10% d quark tensor charge Collins (Sivers) Asymmetries

Expected Improvement: Sivers Function Significant Improvement in the valence quark (high-x) region Illustrated in a model fit (from A. Prokudin) f 1T  =

E : Worm-gear functions (A rating ) Spokespersons: J. P. Chen, J. Huang, Y. Qiang and W. Yan Dominated by real part of interference between L=0 (S) and L=1 (P) states No GPD correspondence Lattice QCD -> Dipole Shift in mom. space. Model Calculations -> h 1L  =? -g 1T. h 1L  = g 1T = Longi-transversity Trans-helicity Center of points:

 Access transversity in transversely polarized neutron target through π + π - di-hadron production  Run simultaneously with SIDIS 3 He (e,e’π ± )X  Systematical check of two approaches to access h 1 Asymmetry projection for one M-z bin

Summary on TMD Program Unprecedented precision 4-d mapping of SSA Collins, Sivers, Pretzelosity and Worm-Gear Both polarized 3 He (n) and polarized proton with SoLID Three “A” rated experiments approved. One LOI on di-hadron. 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 Q 2 evolution Global efforts (experimentalists and theorists), global analysis much better understanding of multi-d nucleon structure and QCD Welcome new collaborators Longer-term future: Electron-Ion Collider to study sea and gluon TMD EIC in China (a new possibility)

Parity Violating DIS at JLab 6 GeV New Results (Slides by X. Zheng)

6 GeV PVDIS Results D. Wang, …, X. Zheng, et al. Nature, 506, 7486, (2014)

World Knowledge on Electron-Quark Contact Interaction Terms Note the equal scale in horizontal and vertical direction. Yet data on C2q won't fit inside the frame.

PVDIS at 6 GeV (JLab E08-011) Ran in Oct-Dec 2009, 100uA, 90% polarized electron beam, 20-cm liquid deuterium target Scaler-based fast counting DAQ specifically built for the 500kHz DIS rates w/ 10 4 pion rejection. Spokespeople: P. Reimer, R. Michaels, X.Z. Postdoc: Ramesh Subedi Grad. Students: Kai Pan (MIT), Xiaoyan Deng (UVa), PhD Students: Diancheng Wang (UVa),

With JLab E Results Improved on C2q by factor of five Agree with Standard Model 2C2u-C2d is two sigma from zero, as predicted by the Standard Model.

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Parity Violating DIS at JLab 12 GeV SoLID Program

PVDIS with SoLID Contact Person: P. Souder High Luminosity on LD2 and LH2 Better than 1% errors for small bins over large range kinematics Test of Standard Model Quark structure: charge symmetry violation quark-gluon correlations d/u at large-x

12 GeV PVDIS Sensitivity: C 1 and C 2 Plots Cs PVDIS Qweak PVDIS World’s data Precision Data 6 GeV

QCD: Charge Symmetry Violation We already know CSV exists: u-d mass differenceδm = m d -m u ≈ 4 MeV δM = M n -M p ≈ 1.3 MeV electromagnetic effects Direct observation of CSV—very exciting! Important implications for PDF’s Could be a partial explanation of the NuTeV anomaly For A PV in electron- 2 H DIS: Broad χ 2 minimum (90% CL) MRST PDF global with fit of CSV Martin, Roberts, Stirling, Thorne Eur Phys J C35, 325 (04) MRST (2004)

SoLID-J/  : Study Non-Perturbative Gluons Quark Energy Trace Anomaly Gluon Energy Quark Mass N/cm 2 /s J/ψ: ideal probe of non-perturbative gluon The high luminosity & large acceptance capability of SoLID enables a unique “precision” measurement near threshold Search for threshold enhancement Shed light on the conformal anomaly X. Ji PRL (1995) Spokespersons: K. Hafidi, Z.E. Meziani, X. Qian, N. Sparveris and Z. Zhao

Summary Nucleon TMD study have been exciting and fruitful Recent and Preliminary Results on TMD studies from JLab JLab 12 GeV : Planned SoLID program on TMDs Precision 4-d mapping of TMD asymmetries Precision experimental data + development in theory for Nucleon TMDs +…  lead to breakthrough in understanding QCD? Results from 6 GeV PVDIS JLab 12 GeV: Solid Program on PVDIS Low energy test of Standard Model Precision Hadron Structure Study: Charge Symmetry Violation, Higher-twist effect, d/u at high x

Backup Slides

Jefferson Lab at a Glance (12 GeV now! )  ~ 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% A B C  12 GeV

Unpolarized and Polarized TMDs Flavor P T Dependence JLab Hall C/B SIDIS Results

Flavor P T Dependence from Theory  Chiral quark-soliton model (Schweitzer, Strikman, Weiss, JHEP, 1301 (2013)  sea wider tail than valance Flagmentation model, Matevosyan, Bentz, Cloet, Thomas, PRD85 (2012)  unfavored pion and Kaon wider than favored pion f 1u/ f 1d kTkT

Hall C Results: Flavor P T Dependence C (d)2(d)2 (u)2(u)2 (-)2(-)2 (+)2(+)2

A 1 P T -dependence CLAS data suggests that width of g 1 is less than the width of f 1 Lattice PTPT arXiv: A 1 B.Musch et al arXiv: plots courtesy of Harut Avagyan

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

Asymmetry A LT Result 3 He A LT : Positive for  - To leading twist: J. Huang et al., PRL. 108, (2012). Worm-Gear.

Inclusive Hadron Electroproduction e + N ↑ h + X (h = , K, p) Why a non-zero A N is interesting? – Analogues to A N 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 p T ~ 1 GeV or more) – To help understand mechanism behind large A N in in the TMD framework pTpT

Transverse SSA in Inclusive Hadron Target spin flip every 20 minutes Acceptance effects cancels Overall systematic check with A N at ϕ S = 0 – False asymmetry < 0.1% ++  False Asymmetry

JLab Physics Program at 12 GeV 49 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

H 2 D 2 Hall C/SHMS L-T studies, precise  + /  - ratios Hall C/SHMS L-T studies, precise  + /  - ratios 3 He, NH 3 Hall A/SBS High x - Q 2, 2-3D Hall A/SBS High x - Q 2, 2-3D Hall A/SOLID High Lumi and acceptance – 4D Hall A/SOLID High Lumi and acceptance – 4D ULT q N U L T H 2 /D 2, NH 3 /ND 3, HD Hall B/CLAS12 General survey, medium luminosity Hall B/CLAS12 General survey, medium luminosity Multi-Halls SIDIS Program

Map Collins and Sivers asymmetries in 4-D (x, z, Q 2, P T )

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 + Haiyan Gao (Duke) reach high precision similar to SoLID at lower x, higher Q2 region

QCD: Higher Twist From the Quark Parton Model (QPM) to QCD 1.Add DGLAP evolution 2.Add higher order terms in the Operator Product Expansion (OPE)↔Higher Twist Terms Parton Model— leading twist Di-quarks Quark-gluon diagram What is a true quark-gluon operator? Quark-gluon operators correspond to transverse momentum QCD equations of motion

PVDIS on the Proton: d/u at High x Deuteron analysis has large nuclear corrections (Yellow) A PV for the proton has no such corrections (complementary to BONUS/MARATHON) 3-month run