SoLID: Precision Study of Nucleon Structure & Test of Standard Model

1. Overview of SoLID: Solenoidal Large Intensity Device for Precision Studyof Nucleon Structure and Test of Standard Model Jian-ping Chen (陈剑平), Jefferson Lab, Virginia, USA 5th Hadron-China Workshop, Huangshan, China, 2013 • SoLID Physics Program @ 12 GeV JLab • Transverse Spin and Transverse Structure: TMDs • Parity Violating DIS • J/y and more • SoLID Instrumentation • Current Status and Plan • SoLID Collaboration • acknowledgement: thanks to SoLID collaborators for some slides

2. Physics Program for SoLID • SoLID: large acceptance, capable of handling high luminosity • (up to~1039 with baffle, up to ~1037 without baffle) • Ideal for precision Inclusive-DIS (PVDIS) and SIDIS experiments • Excellent for selected exclusive reactions (ex. J/Y) • Five high impact experiments approved (4 with “A” rating, 1 A- rating): • SIDIS: E12-10-006 (3He-T), E12-11-007 (3He-L), E12-11-108 (proton-T) • PVDIS: E12-10-007 (deuteron and proton) • J/y: E12-12-006

3. SoLID Physics Program (I) Transverse Spin and Transverse Structure: TMDs

4. QCD: Unsolved in Nonperturbative Region running coupling “constant” • 2004 Nobel prize for ``asymptotic freedom’’ • non-perturbative regime QCD confinement • Nature’s only known truly nonperturbative fundamental theory • One of the top 10 challenges for physics! • QCD: Important for discovering new physics beyond SM • Nucleon: stable lab to study QCD • Nucleon structure is one of the most active areas

5. QCD and Nucleon Structure Study • Dynamical Chiral Symmetry Breaking <-> Confinement • Responsible for ~98% of the nucleon mass • Higgs mechanism is (almost) irrelevant to light quarks • Rapid development in theory • Lattice QCD • Dyson-Schwinger • Ads/CFT: Holographic QCD • …… • Direct comparisons limited to • Moments • Tensor charge • … • Direct comparison becomes possible • Experimental data with predictions from theory C.D. Roberts, Prog. Part. Nucl. Phys. 61 (2008) 50 M. Bhagwat & P.C. Tandy, AIP Conf.Proc. 842 (2006) 225-227 Mass from nothing!

6. Imaging dynamical chiral symmetry breaking: pion wave function on the light front, Lei Chang, et al., arXiv:1301.0324 [nucl-th], Phys. Rev. Lett. 110 (2013) 132001 (2013) [5 pages]. Dyson-Schwinger Pion’s valence-quark Distribution Amplitude C.D. Roberts, Prog. Part. Nucl. Phys. 61 (2008) 50 Dilation of pion’s wave function is measurable in pion’s electromagnetic form factor at JLab12 A-rated:E12-06-10 • Established an one-to-one connection between DCSB and the pointwise form of the pion’s wave function. • Dilation measures the rate at which dressed-quark approaches the asymptotic bare-parton limit • Experiments at JLab12 can empirically verify the behaviour of M(p), and hence chart the IR limit of QCD Craig Roberts: Mapping Parton Structure and Correlations (62p)

7. Lattice QCD A new proposal • Using the IMF formalism. • Start with static correlation in the z-direction. X. Ji, to be published First exploratory study by Huey-Wen Lin presented at the QCD Evolution Workshop at JLab, May 2013.

8. The extension of the approach • GPDs • TMDs

9. Nucleon Spin Quark Spin Leading-Twist TMD PDFs h1= Boer-Mulders f1 = h1L= Worm Gear Helicity g1 = h1= Transversity f1T= g1T= h1T= Sivers Worm Gear Pretzelosity : Survive trans. Momentum integration

10. Status of Transverse Spin/Structure Study Large single spin asymmetry in pp->pX (Fermi, RHIC-spin) Collins Asymmetries - sizable for the proton (HERMES and COMPASS) large at high x,p- and p+has opposite sign unfavored Collins fragmentation as large as favored (opposite sign)? - consistent with 0 for the deuteron (COMPASS) Sivers Asymmetries - non-zero for p+ from proton (HERMES), new COMPASS data - consistent with zero for p- from proton and for all channels from deuteron - large for K+? - sign mismatch? Collins Fragmentation from Belle Global Fits/models: Anselminoet al., Yuan et al., Pasquiniet al., Ma et al., … TMD evolution, a lot of progress in the last couple years 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(3He) at JLab 12 GeV Unprecedented precision with high luminosity and large acceptance Gunar Schnell Jin Huang

11. 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┴,Q2) Multi-facilities, global effort Precision  high statistics high luminosity and large acceptance

12. Nucleon Structure (TMDs) with SoLID • Semi-inclusive Deep Inelastic Scattering program: • Large Acceptance + High Luminosity • + Polarized targets 4-D mapping of asymmetries Tensor charge, TMDs … • Lattice QCD, QCD Dynamics, Models. Solenoidal Large Intensity Device (SoLID) • International collaboration (8 countries, • 50+ institutes and 190+ collaborators) • Rapid Growth in US‐China Collaboration • Chinese Hadron collaboration • (USTC, CIAE, PKU, Tsinghua U, Lanzhou, IMP,+) • - large GEM trackers • - MRPC-TOF • 3 A rated SIDIS experiments approved for SoLID • with 2 having Chinese collaborators as • co-spokesperson (Li from CIAE and Yan from USTC)

13. SoLID Collaborators from China

14. Mapping of Collins/Siver Asymmetries with SoLID E12-10-006 3He(n), Spokespersons: J. P. Chen, H. Gao, X. Jiang, J-C. Peng, X. QianE12-11-007(p) , Spokespersons: K. Allda, J. P. Chen, H. Gao, X. Li, Z-E. Mezinai • 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% u/d quark tensor charge

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

16. E12-11-107: Worm-gear functions (‘A’ rating: ) Spokespersons: J. P. Chen/J. Huang/Y. Qiang/ W. Yan • 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=

17. Precision dihadron (p+/p-) production on a transversely polarized 3He (n) • Extract transversity on neutron • Provide crucial inputs for flavor separation of transversity Measure Transversity via Dihadron with SoLIDLOI to JLab PAC 40, J. Zhang, J. P. Chen, A. Courtoy, H. Gao Wide xb and Q2 coverages Projected Statistics error for one (Mpp,zpp) bin, integrated over all y and Q2.

18. Discussion Unprecedented precision 4-d mapping of SSA Collins and Sivers p+, p- and K+, K- Three “A” rated SIDIS experiments (p and n) with SoLID +LOI Reach ultimate precision: high luminosity and large acceptance 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 charges study TMDs in the valence region study quark orbital angular momentum study Q2 evolution Global efforts (experimentalists and theorists), global analysis much better understanding of multi-d nucleon structure and QCD Long-term future: EIC to map sea and gluon SSAs

19. SoLID Physics Program (II) Parity Violating Deep Inelastic Scattering Precision Test of Standard Model and Precision Study of Hadron Properties

20. NilangaLiyanaga PVDIS with SoLIDE12-10-007: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

21. 12 GeV PVDIS Sensitivity: C1 and C2 Plots World’s data 6 GeV PVDIS Precision Data PVDIS Qweak Cs

22. MRST (2004) QCD: Charge Symmetry Violation We already know CSV exists: • u-d mass difference δm = md-mu ≈ 4 MeV δM = Mn-Mp ≈ 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 APV in electron-2H DIS: MRST PDF global with fit of CSV Martin, Roberts, Stirling, Thorne Eur Phys J C35, 325 (04) Broad χ2 minimum (90% CL)

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

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

25. Zhiwen Zhao SoLID-J/y: Study Non-Perturbative Gluons • 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 Trace Anomaly 50 days @ 1037 N/cm2/s Gluon Energy Quark Energy Quark Mass X. Ji PRL 74 1071 (1995)

26. SoLID Instrumentation Magnet, Detectors, DAQs, Simulations

27. SoLID Instrumentation

28. Solenoidal Magnet • Magnet options studied: (UVa+Argonne+JLab) • First narrowed from 6 options to 2, • CLEO/BaBar/CDF/ZEUS/Glue-X/New •  CLEO or BaBar • Both satisfy needs, both available • Talked to both parties, obtained information • Detailed discussion with CLEO • Field study, force study, • Engineering study, including cost estimation • Site visit •  CLEO was chosen • Discussion with DOE • Position paper sent to DOE, just got favorable response • Will move the magnet to JLab in 2014/2015 • Refurbish

29. Detectors: Overview GEM session • Tracking: GEMs: • Five Chinese groups+ US side: UVa/Temple • Conceptual design mostly complete • R&D on-going, together with SuperBigBite, EIC projects • e/pi separation (I) Electromagnetic Calorimeter (UVa+Los Almos+ W&M) • COMPASS style Shashlyk calorimeter • e/pi separation (II) light gas Cherenkov (Temple) • Magnetic field effect, performance studied, in-beam test • Conceptual design complete, supporting structure • pi/K separation (I) heavy gas Cherenkov (Duke) • Field effect, performance studied • Conceptual design complete, supporting structure • pi/K separation(II) MRPC (Tsinghua) • In-beam test, publication Y. Wang

30. Electromagnetic Calorimeter • 50:1 p suppression, radiation hard • COMPASS style Shashlyk calorimeter chosen over Sci-Fi and other options • New preshower design, including scintillator for photon suppression • Hexagon shape for easy supporting • Simulation with realistic background, impact on DAQ is under study

31. Gas Cheronkov • Light gas Chereonkov, • 100:1 p suppression • P=2-4 GeV (PVDIS), 1.5-4.5 GeV (SIDIS) • C4F8O/N2 mix as radiator for PVDIS • CO2 for SIDIS • PMT performance in field carefully studied • With mu-metal shielding, H8500C Hamamatsu maPMT satisfy needs • Mirror design for both configurations, CFRP with Al+MgF2 coating • Simulation with realistic background, impact on DAQ is under study • Heavy gas Cherenkov, • 100:1 Kaon suppression • P = 2.5-7.5 GeV • C4F8O at 1.5 atm • Mirror: Al +MgF2 coating • Both p+ and p-

32. SoLID in Hall A

33. SoLID Status and Plan • Strong International Collaboration: • 8 countries, 50+ institutes and 190+ collaborators • 10 Chinese institutions, contribute to GEMs (5), MRPC • Magnet: • CLEO magnet chosen, engineering study, position paper to DOE • Simulations: full package with GEANT4, • physics, background, neutrons, detector design, … • Detectors: “finalized” conceptual design • light Cherenkov, heavy Cherenkov, GEMs, MRPC • calorimeters (shashlyk), forward and large-angle • Baffle, DAQ • Targets, Beam Polarimetry • Director’s review: early fall, charge available • 1st draft of Pre-Conceptual Design Report ready • Schedule: review/MIE 2013, DOE approval (CD) process 2013-2015, • construction 2016-2018, experiments starts in 2018? • great opportunities for new groups / young people

34. Collaboration Organization • Institution board: representatives from collaborating groups • Execute committee: • Jian-ping Chen, Haiyan Gao, Zein-Eddine Meziani, Paul Souder • Chair: P. Souder • Projector Manager: • Jian-ping Chen • Technical Committee: • Jian-ping Chen (Chair), Paul Souder, Haiyan Gao, Zein-Eddine Meziani, Paul Reimer, Eugene Chudakov, Nilanga Liyanage, Xiaochao Zheng, Zhengguo Zhao, Xiaodong Jiang, Alexandre Camsonne, Tom Hemmick, Xin Qian. • 19 Subsystems: Owners/groups identified. • New groups welcome.

35. Summary • A challenge: Understand Strong QCD • New development: direct comparison of experiments with theory • Needs multi (transverse) dimension • Needs precision: high luminosity and large acceptance • SoLID @ JLab 12 GeV: exciting physics program 4 “A” rated, 1 “A-” rated experiments approved • SIDIS: Precision extraction of transversity/tensor charge/ TMDs • PVDIS: low energy test of standard model and hadron properties • J/y threshold production: study gluons • LOIs/Future proposals (di-hadron, TCS) • Exciting new opportunities  lead to breakthroughs? • New collaborators welcome