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Polarized 3He Target Lab for

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					                                                                             Yi Qiang
                                                                 Duke University
                    for the Workshop on Hadron Physics in China
                              and Opportunities with 12 GeV JLab
                                                      July 31, 2009



7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   1
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

     7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   2
Nucleon Structure from DIS
 Un-polarized Nucleon Structure Function f1 =
    Longitudinal Momentum Distribution
    Well probed for 50 years over very large kinematics
     range
 Longitudinal Polarized Nucleon Structure Functions
    Since “spin crisis” in 1980s   g1 =
    Plotted in fairly large range
 Transversity:             h1 =
   Can be probed in Semi-Inclusive DIS
   New business: recent measurements from HERMES and
    COMPASS using Hydrogen and Deuteron targets

       7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   3
Leading Twist TMDs
                                                             Quark polarization
                                                                   Longitudinally               Transversely
                                  Un-Polarized
                                                                     Polarized                   Polarized

                        U      f1 =                                                      h1  =
 Nucleon Polarization




                        L                                      g1 =                     h1L =


                                                                                           h1 =
                        T f =                               g1T =
                           1T
                                                                                        h1T =


                                        Blue: kT independent; Red: T-odd
                            7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   4
    Access Leading Twist Parton Distributions
    through Semi-Inclusive DIS
                                       d             2    y2
                                                                  
                                 dxdydS dzdh dPh  xyQ 2(1   )
                                                  2      2


                                {FUU ,T  ...
                                                                                                      Unpolarized
                                                           cos(2h )
Boer-Mulder                       cos(2h )  F         UU            ...
                                 S L [ sin(2h )  FUL 2h )  ...]
                                                       sin(


Transversity                     ST [ sin(h  S )  FUT h S )
                                                          sin(
                                                                                                      Polarized
                                                                                                      Target
   Sivers                        sin(h  S )  ( FUL h S )  ...)
                                                      sin(


Pretzelosity                      sin(3h  S )  FUT 3h S )  ...]
                                                       sin(


                                 S L e [ 1   2  FLL  ...]                         Polarized
                                                                                        Beam and
                                                                  cos(h  S )
                                 ST e [ 1   cos(h  S )  FLT
                                               2
                                                                                 ...]} Target

                  SL, ST: Target Polarization; e: Beam Polarization

               7/31/2009   Neutron Transversity in Jefferson Lab Hall A        Yi Qiang <yqiang@jlab.org>   5
Transversity from JLab Hall A
 Linear accelerator
 provides continuous
 polarized electron beam
   Ebeam = 6 GeV
   Pbeam = 85%
 3 experimental halls


                                                                   A             B             C



       7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>       6
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.


        7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   7
E06-010 Setup
                                              • Electron beam: E = 5.9 GeV
        16o                                   • 40 cm polarized 3He target

            *                                • BigBite at 30 degrees as
                                                electron arm:
                       BigBite
                   30o                               P = 0.7 ~ 1.8 GeV/c
HRSL
                                              • HRSL at 16 degrees as
                                                hadron arm:
        p                                            P0 = 2.35 GeV/c
    Polarized      e’                         • Measure Collins, Sivers and
   3He Target
                                                pretzelosity asymmetries in
              e                                 valence range:
                                                     x = 0.1 ~ 0.4

       7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   8
Separation of Collins, Sivers and Pretzelosity
effects through angular dependence
                   1 N  N
 AUT (hl , S ) 
             l

                   P N  N                                                                 Vertical
                                                                                                       Horizontal
 Rotate target spin direction
  to increase s coverage
                        Ph 
  UT  ST (1  y )          sin(hl  S )   eq h1q ( x) H1 h ( z, Ph2 )
                                        l        2
                                                               q                             Transversity
                       zM h
              y 2 Ph 
  ST (1  y  )       sin(hl  S )   eq f1T q ( x) D1hq ( zh , Ph2 )
                                  l        2 
                                                                                             Sivers
              2 zM N
                 Ph3
  ST (1  y ) 2 2       sin(3hl  S )   eq h1 q ( x) H1 h ( z h , Ph2 ) Pretzelosity
                                     l        2
                                                  T           q
              6z M N M h

           7/31/2009       Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>    9
Polarized                3He             Target
 Effective polarized neutron target
 High luminosity: L(n) = 1036 cm-2 s-1                                 ~90%             ~8%              ~1.5%
 Fast spin exchange with K/Rb hybrid cells

    Laser                                         Oven
    795 nm                                        230 oC
                         Pumping
                         Chamber

                                                  F = 3”

    25 G Holding Field
                                          Target Chamber


                          40 cm

         7/31/2009       Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   10
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.
    7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   11
3He   Target Polarimetries
 NMR: Nuclear Magnetic Resonance
   Free NMR at pumping chamber                                              Water             NMR
    from every auto spin flip.
   Target chamber polarization is
    calibrated by Water NMR
    measurement.
 EPR: Electron Paramagnetic
 Resonance                                                                              EPR
   Got signal from both K and Rb.
   Measures pumping chamber
    polarization.

       7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   12
Target Performance
 Online preliminary EPR/NMR
 analysis shows a stable 65%
 polarization with 15 mA beam
 and 20 minute spin flip




          Cell: Astral                                       Cell: Maureen



      7/31/2009   Neutron Transversity in Jefferson Lab Hall A       Yi Qiang <yqiang@jlab.org>   13
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
        7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   14
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

          7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   15
Electron Selection in BigBite
 Pre-shower/Shower have been calibrated
 Energy Resolution: 8%
 Well separated electrons and pions




       7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   16
Left High Resolution Spectrometer
 16 degrees to beam left with
  p0 = 2.35 GeV/c                                                  p          < 400 ps
 Clean e/p separation with Gas                                               p
  Cherenkov and Pion Rejector                                          K
                                                                                                        K p
 Vertex and TOF coincidence
  with BigBite will help reduce                                            ep Coincidence Time
  the background
 Kaon asymmetry data can also
  be extracted:
    A1: Pion rejection > 90 %
    RICH: K/p separation ~ 4 
    TOF: K/p separation ~ 4                               4  Separation                 Cherenkov Ring
                                                                                             from RICH

        7/31/2009   Neutron Transversity in Jefferson Lab Hall A           Yi Qiang <yqiang@jlab.org>    17
Kinematics Coverage
y
         0.6 ~ 0.9
                                                                                             x<0.25
         0.6 ~ 3     (GeV/c)2
Q2


                                                             Sivers Angle: h  
                                                             CollinsAngle:  -+s s
                                                          Pretzelosity Angle:h3h-s
W’
          1.5 ~ 2.3 (GeV/c2)

         0.4 ~ 0.6
                                                                                             x>0.25
z

     0               0.25 x                 0.5
         7/31/2009      Neutron Transversity in Jefferson Lab Hall A    Yi Qiang <yqiang@jlab.org>   18
Projections of Collins and Sivers Functions




     7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   19
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




       7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   20
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.



      7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   21
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.
          7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   22
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7/31/2009   Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   24
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.


           7/31/2009       Neutron Transversity in Jefferson Lab Hall A   Yi Qiang <yqiang@jlab.org>   25
Fermi Lab E704: p↑p→pX at 400 GeV




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