1. Yi Qiang Duke University for APS April Meeting 2009 May 4, 2009
Measurement of Single Target-Spin Asymmetry in Semi-Inclusive Pion Electroproduction on a Transversely Polarized 3He Target
Yi Qiang
Duke University
for APS April Meeting 2009
May 4, 2009
Transversity in JLab Hall A APS April Meeting 2009
5/4/2009

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/Los Alamos, Contact Person), Jian-ping Chen (JLab), Evaristo Cisbani (INFN-Rome), Haiyan Gao (Duke), Jen-Chieh Peng (UIUC)
Thesis Students:
C. Dutta (Kentucky), J. Huang (MIT), A. Kalyan (Kentucky), J. Katich (W&M), X. Qian (Duke), Y. Wang (UIUC), Y. Zhang (Lanzhou U)
Approved with A rating and was just finished in early February, 2009.
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

3. Access Leading Twist Parton Distributions through Semi-Inclusive DIS
Unpolarized
Boer-Mulder
Measured by E06-010
Transversity
Polarized
Target
Sivers
Measured as well
see Jin Huang’s talk
Pretzelosity
Polarized
Beam and
Target
SL, ST: Target Polarization; le: Beam Polarization
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

4. Transversity in JLab Hall A APS April Meeting 2009
Experiment Setup
Electron Beam: E = 5.9 GeV
HRSL at 16 degrees as hadron arm: P = 2.4 GeV/c
BigBite at 30 degrees as electron arm: P = 0.5 ~ 2.2 GeV/c
Measure Collins, Sivers and pretzelosity asymmetries in valence range: x = 0.13 ~ 0.41 e e’ p g*
HRSL
BigBite
16o
30o
Polarized
3He Target
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

5. Transversity in JLab Hall A APS April Meeting 2009
Polarized 3He Target
EPR
Water NMR
Auto spin flip every 20 minutes
High Polarization with 3x25 W narrow band COMET lasers: p ~ 65% (~70% Max)
Good Polarimetries Calibration: EPR and Water NMR
Cell: Astral
Cell: Maureen
see Chiranjib Dutta’s Talk for more details
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

6. Reconstructed Pattern
BigBite Spectrometer
Wire chamber survives at 45MHz rate with 13.5 uA beam
Spatial resolution: 180um
Clean e/p separation with Shower/Pre-shower
See Kalyan Allada’s talk for more details
Sieve Plate p e
Reconstructed Pattern
With BigBite OFF
Chamber Hit Efficiency
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

7. Left High Resolution Spectrometer
Clean e/p separation with Gas Cherenkov and Pion Rejector
Good time resolution from S2m scintillator plane: < 600 ps
Promising K/p separation with A1 and RICH detectors
Cherenkov Ring
from RICH
4.5s Separation
Raw S2m time
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

8. Transversity in JLab Hall A APS April Meeting 2009
Separation of Collins, Sivers and Pretzelosity effects through angular dependence
Transversity
Sivers
Pretzelosity
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

9. Projections of Collins and Sivers Functions
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

10. Transversity in JLab Hall A APS April Meeting 2009
Status of E06-010
The experiment was smoothly performed from Oct 2008 to Feb 2009.
Statistics achieved the proposed goal.
Detector calibrations and target analysis are ongoing.
Will start to extract physical asymmetries afterwards.
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

11. Transversity in JLab Hall A APS April Meeting 2009
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 preliminary result really soon!
Measured single arm single spin asymmetry, see Joe Katich’s talk.
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009

13. 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.
5/4/2009
Transversity in JLab Hall A APS April Meeting 2009