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The first measurement of neutron Transversity using a transversely polarized 3 He target

The first measurement of neutron Transversity using a transversely polarized 3 He target. Yi Qiang Duke University for the Workshop on Hadron Physics in China and Opportunities with 12 GeV JLab July 31, 2009. Outline. Overview of leading twist TMDs Jefferson Lab Experiment E06-010

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The first measurement of neutron Transversity using a transversely polarized 3 He target

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  1. The first measurement of neutron Transversity using a transversely polarized 3He target Yi Qiang Duke University for the Workshop on Hadron Physics in China and Opportunities with 12 GeV JLab July 31, 2009 Neutron Transversity in Jefferson Lab Hall A

  2. Outline • Overview of leading twist TMDs • Jefferson Lab Experiment E06-010 • First neutron Transversity experiment • Experimental configuration • Polarized 3He target • Detector performance • Future plan and impact Neutron Transversity in Jefferson Lab Hall A

  3. Nucleon Structure from DIS • Un-polarized Nucleon Structure Function • Longitudinal Momentum Distribution • Well probed for 50 years over very large kinematics range • Longitudinal Polarized Nucleon Structure Functions • Since “spin crisis” in 1980s • Plotted in fairly large range • Transversity: • Can be probed in Semi-Inclusive DIS • New business: recent measurements from HERMES and COMPASS using Hydrogen and Deuteron targets f1 = g1 = h1 = Neutron Transversity in Jefferson Lab Hall A

  4. Leading Twist TMDs Blue: kT independent; Red: T-odd f1 = h1= g1 = h1L= h1 = f1T= g1T = h1T= Neutron Transversity in Jefferson Lab Hall A

  5. Access Leading Twist Parton Distributions through Semi-Inclusive DIS SL, ST: Target Polarization; le: Beam Polarization Unpolarized Boer-Mulder Transversity Polarized Target Sivers Pretzelosity Polarized Beam and Target Neutron Transversity in Jefferson Lab Hall A

  6. Transversity from JLab Hall A • Linear accelerator provides continuous polarized electron beam • Ebeam = 6 GeV • Pbeam = 85% • 3 experimental halls A C B Neutron Transversity in Jefferson Lab Hall A

  7. E06-010 Collaboration • 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. Neutron Transversity in Jefferson Lab Hall A

  8. E06-010 Setup • Electron beam: E = 5.9 GeV • 40 cm polarized 3He target • BigBite at 30 degrees as electron arm: P = 0.7 ~ 1.8 GeV/c • HRSL at 16 degrees as hadron arm: P0 = 2.35 GeV/c • Measure Collins, Sivers and pretzelosity asymmetries in valence range: x = 0.1 ~ 0.4 16o g* BigBite 30o HRSL p e’ Polarized 3He Target e Neutron Transversity in Jefferson Lab Hall A

  9. Separation of Collins, Sivers and Pretzelosity effects through angular dependence • Rotate target spin direction to increase fs coverage Vertical Horizontal Transversity Sivers Pretzelosity Neutron Transversity in Jefferson Lab Hall A

  10. Polarized 3He Target • Effective polarized neutron target • High luminosity: L(n) = 1036 cm-2 s-1 • Fast spin exchange with K/Rb hybrid cells ~90% ~8% ~1.5% Oven 230 oC Laser 795 nm Pumping Chamber F = 3” 25 G Holding Field Target Chamber 40 cm Neutron Transversity in Jefferson Lab Hall A

  11. Target Setup 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. • 3He spin pumped to horizontal and vertical directions. • Auto spin flip every 20 minutes. Neutron Transversity in Jefferson Lab Hall A

  12. 3He Target Polarimetries • NMR: Nuclear Magnetic Resonance • Free NMR at pumping chamber from every auto spin flip. • Target chamber polarization is calibrated by Water NMR measurement. • EPR: Electron Paramagnetic Resonance • Got signal from both K and Rb. • Measures pumping chamber polarization. Water NMR EPR Neutron Transversity in Jefferson Lab Hall A

  13. Target Performance • Online preliminary EPR/NMR analysis shows a stable 65% polarization with 15 mA beam and 20 minute spin flip Online Preliminary Cell: Astral Cell: Maureen Neutron Transversity in Jefferson Lab Hall A

  14. BigBite Spectrometer • 30 degrees to the beam right • Detect electrons • A big bite of acceptance • DW = 64 msr • P : 700 ~ 1800 MeV/c • 3 Wire Chambers: 18 planes • Optics is crucial for the angular dependence separation and kinematics variables • Pre-Shower and Shower for electron PID Neutron Transversity in Jefferson Lab Hall A

  15. BigBite Optics • Optics for both negative and positive charged particles have been done • Wire Chamber Spatial Resolution: 180 mm • Vertex Resolution: 1 cm • Angular Resolution: < 10 mrad • Momentum Resolution: 1% BigBite Sieve Slit Neutron Transversity in Jefferson Lab Hall A

  16. Electron Selection in BigBite • Pre-shower/Shower have been calibrated • Energy Resolution: 8% • Well separated electrons and pions Neutron Transversity in Jefferson Lab Hall A

  17. Left High Resolution Spectrometer • 16 degrees to beam left with p0 = 2.35 GeV/c • Clean e/p separation with Gas Cherenkov and Pion Rejector • Vertex and TOF coincidence with BigBite will help reduce the background • Kaon asymmetry data can also be extracted: • A1: Pion rejection > 90 % • RICH: K/p separation ~ 4 s • TOF: K/p separation ~ 4 s s < 400 ps p p K p K ep Coincidence Time Cherenkov Ring from RICH 4 s Separation Neutron Transversity in Jefferson Lab Hall A

  18. Kinematics Coverage y 0.6 ~ 0.9 x<0.25 0.6 ~ 3 (GeV/c)2 Q2 Pretzelosity Angle: 3fh-fs Sivers Angle: fh-fs Collins Angle: fh+fs W’ 1.5 ~ 2.3 (GeV/c2) x>0.25 0.4 ~ 0.6 z 0 0.25 0.5 x Neutron Transversity in Jefferson Lab Hall A

  19. Projections of Collins and Sivers Functions Neutron Transversity in Jefferson Lab Hall A

  20. Projections of g1T • First Neutron (3He) Measurement • With Fast Beam Helicity Flip (30Hz) • Projected Uncertainties (Stat. Only): • 2.3% at low x • 3.4% at high x Neutron Transversity in Jefferson Lab Hall A

  21. Status of E06-010 • The experiment was smoothly performed from Oct 2008 to Feb 2009. • Statistics exceeded the approved goal. • Detector calibrations and target analysis are ongoing. • Will start to extract physical asymmetries afterwards. Neutron Transversity in Jefferson Lab Hall A

  22. Future Plan and Impact • Finish all the data quality check, detector calibration and target analysis by Sep 2009. • Extract raw asymmetries: witness channel, blind analysis and then raw physics asymmetry by Nov 2009. • Apply other corrections: dilution factor, background asymmetry correction, radiative correction and etc. • Final asymmetries separation: Collins, Sivers … • The results from this experiment will provide important constraints on the TMDs of u, d and s quarks in the valence quark region when combined with world data. • The experience obtained will greatly help us to plan the future SIDIS experiments. Neutron Transversity in Jefferson Lab Hall A

  23. Neutron Transversity in Jefferson Lab Hall A

  24. Backup Slides Neutron Transversity in Jefferson Lab Hall A

  25. E06-010 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. Neutron Transversity in Jefferson Lab Hall A

  26. Fermi Lab E704: p↑p→pX at 400 GeV Neutron Transversity in Jefferson Lab Hall A

  27. Neutron Transversity in Jefferson Lab Hall A

  28. Neutron Transversity in Jefferson Lab Hall A

  29. Neutron Transversity in Jefferson Lab Hall A

  30. Neutron Transversity in Jefferson Lab Hall A

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