Download presentation

Presentation is loading. Please wait.

Published byCharleen McCoy Modified over 5 years ago

1
New results on Neutron Single Target Spin Asymmetries from Transversely polarized 3 He target at Jlab Nilanga Liyanage, University of Virginia Recent SSA Results from JLab Hall A with a Transversely Polarized 3 He (n) Collins/Sivers Asymmetries on pi+/pi- (published) Worm-gear II Asymmetries on pi+/pi- (published) New Preliminary SSA Results from JLab Hall A with a Transversely polarized 3 He (n) Collins/Sivers Asymmetries in K+/K- Pretzelosity Asymmetries on +/ - Inclusive hadron SSA Inclusive electron SSA (DIS, QE) TMD study at JLab 12 GeV in Hall A: SoLID Program on SSA/TMDs: 3 Approved Experiments on 3 He and p Acknowledgement: thanks to J.P Chen and Jefferson lab Transversity collaboration for some slides

2
Unpolarized Structure Function F 2 Bjorken Scaling Scaling Violation Gluon radiation – QCD evolution NLO: Next-to-Leading-Order One of the best experimental tests of QCD

3
Parton Distribution Functions (CTEQ6) JHEP 1001: 109 (2010)

4
Polarized Structure functions

5
Polarized Parton Distributions DSSV, PRL101, 072001 (2008)

6
3-D Structure Generalized Parton Distributions Transverse Momentum-Dependent Distributions The next Frontier

7
TMDs 2+1 D picture in momentum space Bacchetta, Conti, Radici GPDs 2+1 D picture in impact-parameter space QCDSF collaboration Towards Imaging - Two Approaches intrinsic transverse motion spin-orbit correlations- relate to OAM non-trivial factorization accessible in SIDIS (and Drell-Yan) collinear but long. momentum transfer indicator of OAM; access to Ji’s total J q,g existing factorization proofs DVCS, exclusive vector-meson production

8
Transverse Spin: Transversity Three twist-2 quark distributions: Momentum distributions: q(x,Q 2 ) = q ↑ (x) + q ↓ (x) Longitudinal spin distributions: Δq(x,Q 2 ) = q ↑ (x) - q ↓ (x) Transversity distributions: δq(x,Q 2 ) = q ┴ (x) - q ┬ (x) It takes two chiral-odd objects to measure transversity Semi-inclusive DIS Chiral-odd distributions function (transversity) Chiral-odd fragmentation function (Collins function) TMDs: (without integrating over P T ) Distribution functions depends on x, k ┴ and Q 2 : δq, f 1T ┴ (x, k ┴,Q 2 ), … Fragmentation functions depends on z, p ┴ and Q 2 : D, H 1 (x,p ┴,Q 2 ) Measured asymmetries depends on x, z, P ┴ and Q 2 : Collins, Sivers, … (k ┴, p ┴ and P ┴ are related)

9
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 E06-010 Nucleon Spin Quark Spin

10
Separation of Collins, Sivers and pretzelocity effects through angular dependence

11
Operated by the Southeastern Universities Research Association for the U.S. Department of Energy Thomas Jefferson National Accelerator Facility COMPASS Sivers asymmetry 2010 data x > 0.032 region - comparison with HERMES results

12
E06 ‑ 010 Experiment Spokespersons: Chen/Evaristo/Gao/Jiang/Peng First measurement on n ( 3 He) 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 7 PhD Thesis Students (All graduated) + new students 12 Beam Polarimetry (Møller + Compton) Luminosity Monitor

13
Published Results (I) from JLab Hall A E06-010 with a Transversely Polarized 3 He (n) Collins/Sivers Asymmetries on +/ - X. Qian at al., PRL 107:072003(2011)

14
E06-010 3 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

15
Results on Neutron Collins asymmetries are not large, except at x=0.34 Sivers negative Blue band: model (fitting) uncertainties Red band: other systematic uncertainties

16
Published Results (II) from JLab Hall A E06-010 with a Transversely Polarized 3 He (n) Worm-Gear II: Trans-helicity on +/ - J. Huang et al., PRL. 108, 052001 (2012).

17
Asymmetry A LT Result 3 He A LT : Positive for - To leading twist:

18
–Corrected for proton dilution, f p –Predicted proton asymmetry contribution < 1.5% (π + ), 0.6% (π - ) –Dominated by L=0 (S) and L=1 (P) interference Consist w/ model in signs, suggest larger asymmetry Neutron A LT Extraction Trans-helicity

19
Preliminary New Results (I) from JLab Hall A E06-010 with a Transversely Polarized 3 He (n) Collins/Sivers Asymmetries on K+/K- Analysis by Y. Zhao (USTC), Y. Wang (UIUC)

20
Kaon PID by Coincidence time of flight Cross checked with RICH results K+/π+ ratio: ~5% K-/π- ratio: ~1%

21
Preliminary K+/K- Collins and Sivers Asymmetries on 3 He

22
Preliminary New Results (II) from JLab Hall A E06-010 with a Transversely Polarized 3 He (n) Pretzelosity on +/ - Analysis by Y. Zhang (Lanzhou) and X. Qian (Caltech)

23
Pretzelosity on +/ - Preliminary

24
Extracted Results on Neutron

25
Preliminary New Results (III)from JLab Hall A E06-010 with a polarized 3 He (n) Inclusive Electron SSA Analysis by J. Katech(W&M), X. Qian (Caltech)

26
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 and M. Schlegel’s talks (Tuesday)

27
Inclusive Target Single-Spin Asymmetry Extracted neutron SSA Vertically polarized target

28
Future: TMD study with SoLID at 12 GeV JLab Hall A Precision 4-D mapping of Collins/Sivers/Pretzelosity Worm-Gear I/II with Polarized 3 He (Neutron) and Proton

29
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

30
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: eight countries and 50+ institutions CLEOII Magnet GEMs for tracking Cherenkov and EM Calorimeter for electron PID Heavy Gas Cherenkov and MRPC (TOF) for pion PID

31
E12-10-006/E12-11-108, Both Approved with “A” Rating Mapping of Collins(Sivers) Asymmetries with SoLID Both + and - Precision Map in region x(0.05-0.65) z(0.3-0.7) Q 2 (1-8) P T (0-1.6) <10% d quark tensor charge Collins Asymmetry

32
Map Collins and Sivers asymmetries in 4-D (x, z, Q 2, P T )

33
Expected Improvement: Sivers Function Significant Improvement in the valence quark (high-x) region Illustrated in a model fit (from A. Prokudin) f 1T =

34
E12-11-107 : Worm-gear functions (“A’ rating: ) Spokespersons: Chen/Huang/Qiang/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:

35
Future: TMD study with SoLID at 12 GeV JLab Hall A New Letter Of Intent: Dihadron Production

36
Measure Transversity via Dihadron with SoLID LoI submitted to Jlab PAC 40, J. Zhang, A. Courtoy, et al. Wide x b and Q 2 coverages Projected Statistics error for one (M ,z ) bin, integrated over all y and Q 2. Precision dihadron ( +/ -) production on a transversely polarized 3 He (n) Extract transversity on neutron Provide crucial inputs for flavor separation of transversity

37
Projected Statistics Error Hall A, SoLID program Polarized 3 He target, (~60% polarization) Lumi=10 36 (n)/s/cm 2 Wide x b and Q 2 coverages Bin central values labeld on axises 4-d (x b, Q 2, Z + -,M + - ) mapping Z scale (color) represent stat. error

38
Summary SSA and TMD study have been exciting and fruitful Recent and Preliminary Results from JLab Hall A with a transversely polarized 3 He (n) target Collins/Sivers asymmetries for +/ -/K+/K- Pretzelosity on pi+/pi- SSA: inclusive hadron SSA: inclusive electron DIS SSA: inclusive electron (Quasi)Elastic Planned SoLID program with JLab12 Precision 4-d mapping of TMD asymmetries

Similar presentations

© 2021 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google