1. Yi Qiang Duke University for SPIN 2008 Conference Oct 9, 2008
Measurement of Single Target-Spin Asymmetry in Semi-Inclusive Pion Electroproduction on a Transversely Polarized 3He Target
Yi Qiang
Duke University
for SPIN 2008 Conference
Oct 9, 2008
Transversity in JLab Hall A Spin 2008 Conference
10/9/2008

2. Transversity Experiments in Hall A
E06-010: Single Target-Spin Asymmetry in Semi-Inclusive n↑(e, e’p+/-) Reaction on a Transversely Polarized 3He Target
Spokespersons:
Xiaodong Jiang (Rutgers, Contact Person), Jian-ping Chen (JLab), Evaristo Cisbani (INFN-Rome), Haiyan Gao (Duke), Jen-Chieh Peng (UIUC)
Thesis Students:
C. Dutta (Kentucky), A. Kalyan (Kentucky), X. Qian (Duke), Y. Wang (UIUC), Y. Zhang (Lanzhou U), J. Huang (MIT)
Approved with A rating, total beam time of 29 days, will run in fall 2008
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

3. Collaboration members
E Collaboration
Institutions
California State Univ., Duke Univ., Florida International. Univ., Univ. Illinois, JLab, Univ. Kentucky, LANL, Univ. Maryland, Univ. Massachusetts, MIT, Old Dominion Univ., Rutgers Univ., Temple Univ., Penn State Univ., Univ. Virginia, College of William & Mary, Univ. Sciences & Tech, China Inst. Of Atomic Energy, Beijing Univ., Seoul National Univ., Univ. Glasgow, INFN Roma and Univ. Bari, Univ. of Ljubljana, St. Mary’s Univ., Tel Aviv Univ.
Collaboration members
A.Afanasev, K. Allada, J. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, F. Butaru, G. Cates, C. Chang, J.-P. Chen (Co-SP), W. Chen, S. Choi, C. Chudakov, E. Cisbani(Co-SP), E. Cusanno, R. De Leo, A. Deur, C. Dutta, D. Dutta, R. Feuerbach, S. Frullani, L. Gamberg, H. Gao(Co-SP), F. Garibaldi, S. Gilad, R. Gilman, C. Glashausser, J. Gomez, M. Grosse-Perdekamp, D. Higinbotham, T. Holmstrom, D. Howell, J. Huang, M. Iodice, D. Ireland, J. Jansen, C. de Jager, X. Jiang (Co-SP), Y. Jiang, M. Jones, R. Kaiser, A. Kalyan, A. Kelleher, J. Kellie, J. Kelly, A. Kolarkar, W. Korsch, K. Kramer, E. Kuchina, G. Kumbartzki, L. Lagamba, J. LeRose, R. Lindgren, K. Livingston, N. Liyanage, H. Lu, B. Ma, M. Magliozzi, N. Makins, P. Markowitz, Y. Mao, S. Marrone, W. Melnitchouk, Z.-E. Meziani, R. Michaels, P. Monaghan, S. Nanda, E. Nappi, A. Nathan, V. Nelyubin, B. Norum, K. Paschke, J. C. Peng(Co-SP), E. Piasetzky, M. Potokar, D. Protopopescu, X. Qian, Y. Qiang, B. Reitz, R. Ransome, G. Rosner, A. Saha, A. Sarty, B. Sawatzky, E. Schulte, S. Sirca, K. Slifer, P. Solvignon, V. Sulkosky, P. Ulmer, G. Urciuoli, K. Wang, Y. Wang, D. Watts, L. Weinstein, B. Wojtsekhowski, H. Yao, H. Ye, Q. Ye, Y. Ye, J. Yuan, X. Zhan, Y. Zhang, X. Zheng, S. Zhou.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

4. Leading Twist Quark Distributions
Eight Parton Distribution Functions
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

5. Access Parton Distributions through Semi-Inclusive DIS
Unpolarized
Boer-Mulder
Transversity
Polarized
Target
Sivers
Pretzelosity
Polarized
Beam and
Target
SL, ST: Target Polarization; le: Beam Polarization
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

6. E06-010 SIDIS on Polarized 3He neutron Target
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

7. Jefferson Lab Experiment Halls
Ebeam = 6 GeV
Pbeam = 85%
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

8. Transversity in JLab Hall A Spin 2008 Conference
Experiment Setup
Polarized 3He Target, 10 atm pressure. With 10 uA beam: L(n) = 1036 cm-2 s-1
HRSL at 16 degrees as hadron arm. P = 2.4 GeV/c
BigBite at 30 degrees as electron arm. DW = 64 msr e e’ p g*
HRSL
BigBite
16o
30o
Polarized
3He Target
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

9. Hall A Polarized 3He Target
Optical Pumping System
High Luminosity:
L = 1036 cm-1s-1 (world record)
K-Rb Hybrid Cell
High polarization:
P ~ 45% with beam and 100 W diode laser array
Short Pumping Up Time: 2-6 hours
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

10. Upgrade for Transversity
New vertical coil together with existing horizontal coils and new oven allow 3He to be polarized in ALL three directions!
New narrow band COMET lasers make optical pumping more efficient: ~70% polarization without beam and expecting >60% polarization with beam.
New optics/control system to allow frequent spin flips.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

11. Transversity in JLab Hall A Spin 2008 Conference
Spin Flip/Rotation
Target spin will be rotated to increase the Fsl coverage:
Total beam time splits into vertical and transverse periods.
Target spin gets flipped every 20 minutes, driven by RF to reduce systematic error.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

12. Transversity in JLab Hall A Spin 2008 Conference
Kinematic Coverage
E-arm at θ=30°.
0.5 < E’ < 2.2 GeV.
0.13 < x < 0.405, covers the valence-quark region.
1.3 < Q2 < 3.1 (GeV/c)2.
2.33 < W < 3.05 GeV/c2, above the resonance region.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

13. Transversity in JLab Hall A Spin 2008 Conference
Kinematic Coverage
H-arm at θ= 16°, measure charged hadrons with p = 2.4 GeV/c.
The fraction of the energy transfer carried by the hadrons, z = Eh /ν, is about 0.5 , selecting leading hadrons in the current fragmentation.
Missing mass W ’ > 1.5 GeV/c2 to stay away from the resonance production region.
Pt cover to ~ 0.5 GeV/c.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

14. Separation of Collins and Sivers effects through angular dependence
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

15. Coverage of the Collins Angle
Fsl=0o (black), Fsl=90o (red), Fsl=180o (blue), Fsl=270o (purple)
<x>=0.135
<x>=0.315
<x>=0.225
<x>=0.405
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

16. Coverage of the Sivers Angle
Fsl=0o (black), Fsl=90o (red), Fsl=180o (blue), Fsl=270o (purple)
<x>=0.135
<x>=0.315
<x>=0.225
<x>=0.405
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

17. Collins Asymmetry on neutron
Model Assumptions:
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

18. Collins Asymmetry on neutron
Small Collins Asymmetry
with JLab 6 GeV?
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

19. Sivers Asymmetry on neutron
<Q2>=2.2 (GeV/c)2
Considering that Compass and Hermes did not get consistent proton Sivers, our measurement may help to understand the issue.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

20. Sivers Asymmetry on neutron
<Q2>=2.2 (GeV/c)2
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

21. Transversity in JLab Hall A Spin 2008 Conference
Status of E06-010
Installation started June 9th.
A BigBite detector test run conducted May 2008.
Both 3He target and detector preparation are under going. No major problems so far.
Two weeks to start commissioning and data taking: Oct 24, 2008 – Feb 5, 2009!
Will parasitically take data on Single Arm Single Spin Asymmetry and Double Spin Asymmetry.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

22. Transversity in JLab Hall A Spin 2008 Conference
Summary
First measurement of neutron transversity from polarized 3He Target.
Data will cover valence range, x = 0.13~0.405.
High luminosity and statistics. Absolute error on neutron pion asymmetries is about 3%~5%.
Seeing beam really soon!
Will also have data on double spin asymmetries and single arm single spin asymmetry.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

23. Double Spin Asymmetry g1T
g1T : the quark longitudinal polarization in a transversely polarized nucleon.
We expect to measure ALT at 4 kinematics points together transversity.
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

24. Transversity in JLab Hall A Spin 2008 Conference
ALT in E Transversity
Error is estimated to be
So, Expected Error is about
3% to 5% for
x=0.14 to 0.40
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference

25. Transversity in JLab Hall A Spin 2008 Conference
Water NMR Calibration
10 Sweeps
2500 Sweeps
10/9/2008
Transversity in JLab Hall A Spin 2008 Conference