sidis with solid and a polarized 3 he target haiyan gao duke university durham, nc, u.s.a. ( solid...
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SIDIS with SoLID and a polarized 3He target
Haiyan Gao Duke University
Durham, NC, U.S.A.
(
SoLID Collaboration Meeting October 14-15, 2011
Imaging the Nucleonthree-dimensions (example, GPD)
gives transverse spatial distribution of quark (parton) with momentum fraction x
Fourier transform in momentum transfer
x < 0.1 x ~ 0.3 x ~ 0.8
What about three-dimensional momentum space?
Lepton Scattering ----- A powerful tool
tagging the struck quark through leading hadrons (semi-inclusive DIS)to image in 3-momentum space
x=1 维纵向动量
8 New TMD PDFs f1(x,kT), .. h1(x,kT)
All Leading Twist TMDs
f 1T =
f1 =
g1 =
g1T =
h1L =
h1 =
h1T =
h1T =
TransversityTransversity
Boer-MulderBoer-Mulder
PretzelosityPretzelositySiversSivers
HelicityHelicity
Nucleon SpinQuark Spin
Access Parton Distributions through Semi-Inclusive DIS
...]})cos(1[
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,
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Unpolarized
PolarizedTarget
PolarizedBeam andTarget
SL, ST: Target Polarization; e: Beam Polarization
Boer-Mulders
Sivers
Transversity
Pretzelosity
Separation of Collins, Sivers and pretzelocity effects through angular dependence
1( , )
sin( ) sin( )
sin(3 )
l lUT h S
h SSiverCollins
Pretzelosi
UT
tyU
sUT h S
h ST
N NA
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sin(3 )
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PretzelosityU
SiversUT
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SIDIS SSAs depend on 4-D variables (x, Q2, z and PT )
Large angular coverage and precision measurement of asymmetries
in 4-D phase space is essential.
PAC-37 PR12-11-007 Jin Huang <[email protected]> 7
TMDs in SIDIS Cross Section
...]})3sin(
...)()sin(
)sin([
...])cos(1[
...]1[
...])2sin([
...)2cos(
{
)1(2
)3sin(
)sin(
)sin(
)cos(2
2
)2sin(
)2cos(
,
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f1 =
Sivers f 1T =
Transversity h1T =
Boer-Mulder h1 =
Pretzelosity h1T =
SL, ST: Target Polarization; e: Beam Polarization
h1L =Worm Gear
g1T =Worm Gear
g1 =Helicity
JLab E06‑010 Experiment
• Polarized 3He Target, > 60% with beam, world record
• Polarized Electron Beam – ~80% Polarization– Fast Flipping at 30Hz– PPM Level Charge Asymmetry
controlled by online feed back• BigBite at 30º as Electron Arm
– Pe = 0.7 ~ 2.2 GeV/c
• HRSL at 16º as Hadron Arm– Ph = 2.35 GeV/c
8
Beam Polarimetry(Møller + Compton)
LuminosityMonitor
Spokespersons: Chen, Cisbani, Gao, Jiang and Peng
Results on Neutron• Sizable Collins π+
asymmetries at x=0.34?– Sign of violation of
Soffer’s inequality?– Data are limited by stat.
Needs more precise data!
• Negative Sivers π+
Asymmetry– Consistent with
HERMES/COMPASS– Independent
– demonstration of negative d quark Sivers function.
Model (fitting) uncertainties shown in blue band. Experimental systematic uncertainties: red bandX. Qian et al, Phys. Rev. Lett. 107, 072003 (2011)
Best Measurements on Neutron at High x
UIUC Seminar
Double Spin ALT worm-gear function
• Dominated by real part of interference between L=0 (S) and L=1 (P) states – Imaginary part -> Sivers effect, Boer-Mulders
• No GPD correspondence– a genuine sign of intrinsic transverse motion
• First TMDs in Lattice calculation– arXiv:0908.1283 [hep-lat], arXiv:1011.1213 [hep-lat]
Preliminary
g1T =
Worm Gear
• First data with 3He• 30 Hz beam helicity flips
• Data suggest non-zero SIDIS ALT: π-, +2.8σ (sum all bins)
J. Huang et al., submitted to PRL
12 GeV Upgrade Project12 GeV Upgrade Project
New Hall
Add arc
Enhanced capabilitiesin existing Halls
Add 5 cryomodules
Add 5 cryomodules
20 cryomodules
20 cryomodules
Scope of the project includes: •Doubling accelerator beam energy•New experimental Hall and beamline•Upgrades to existing Experimental Halls
Upgrade arc magnets and supplies
CHL upgrade
•310 million US$ construction project •Construction started 2009•Currently 50% complete•Beam starts 2013
E12-10-006: Nucleon Transversity at 11 GeV Using
a Polarized 3He Target and SOLid in Hall A
Approved by JLab PAC35 A-rating by PAC38
(Beijing U., CalState-LA, CIAE, W&M, Duke, FIU, Hampton, Huangshan U., Cagliari U. and INFN, INFN-Bari and U. of Bari, INFN-Frascati, INFN-Pavia,Torino U. and INFN, JLab, JSI (Slovenia), Lanzhou U, LBNL, Longwood U, LANL, MIT, Miss. State, New Mexico, ODU, Penn State at Berks, Rutgers, Seoul Nat. U., St. Mary’s, Syracuse, Tel aviv, Temple, Tsinghua U, UConn, Glasgow, UIUC, Kentucky, Maryland, UMass, New Hampshire, USTC, UVa and the Hall A CollaborationStrong theory support, Over 130 collaborators, 40 institutions, 8 countries, strong overlap with PVDIS Collaboration
Spokespersons: Chen, Gao (contact), Jiang, Peng and Qian
180+ collaborators, 50+ institutes, strong theory supportsand the Hall A Collaboration
Spokespersons
Jian-Ping Chen (JLab)
Jin Huang (MIT)
Yi Qiang (JLab)
Wenbiao Yan (USTC, China)
Approved by JLab PAC37
A-rating by PAC38
GEMs
(study done with CDF magnet, 1.5T)
Study done with CDF and BarBar magnets (CDF shown here)
Experiment E12-10-006
Kinematic Coverage• Precision 4-D (x, Q2, pT and z)
mapping of Collins, Sivers and pretzelosity.
• Coverage with 11 GeV beam shown here– Black: forward angle– Green: large angle
• xB: 0.1 ~ 0.6
• PT: 0 ~ 1.5 GeV/c
• W: 2.3 ~ 4 GeV• z: 0.3 ~ 0.7• Mm: 1.6~ 3.3 GeV
• Large coverage in kinematic space• 2 beam energy -> Q2 coverage; rad. cor.
PAC-37 PR12-11-007 Jin Huang <[email protected]> 17
Kinematic Coverage
xbj xbj xbj
Q2 (GeV2) Ph⊥ (GeV/c) z
11GeV Beam11GeV Beam
8.8GeV Beam
8.8GeV Beam
Electron:•Forward Det.•Large Angle Det.
E12-10-006 projection on Collins (Sivers)• Total 1400 bins in x, Pt and z for 11/8.8 GeV beam.• z ranges from 0.3 ~ 0.7, only a sub-range of 11/8.8 GeV shown here.
Power of SOLID (E12-10-006)
• Projection of a single Q2-z bin for π-
PAC-37 PR12-11-007 Jin Huang <[email protected]> 20
E12-11-007 Projection/ALT (Partial)
Cen
ter
of p
oint
s:
Sca
le f
or e
rror
bar
s:
• Strong theory supports• 4 sets of predictions calculated for this proposal
• Strong theory supports• 4 sets of predictions calculated for this proposal
• Projection of a single Q2-z bin for π+
PAC-37 PR12-11-007 Jin Huang <[email protected]> 21
E12-11-007 Projection/AUL (Partial)C
ente
r of
poi
nts:
Sca
le f
or e
rror
bar
s:
>1000 bins: critical for studying multi-D structurez= 0.3~0.7
Q2 =
1~8
GeV
2
Ph⊥
(G
eV/c
) xbj
Sca
le f
or e
rror
bar
s : π
+ A
UL
Measure SSA in SIDIS using transversely polarized proton target
Use similar detector setup as that of two approved 3He SoLID expts.
Use JLab/UVa polarized NH3 target with upgraded design of the magnet
Target spin-flip every two hours with average in-beam polarization of 70%
Two Beam energies: 11 GeV and 8.8 GeV Polarized luminosity with 100nA current: 1035
cm-2s-1
Beamline chicane to transport beam through 5T target magnetic field (already designed for g2p expt.)
NH3NH3targettarget
New Proposal PR12-11-108: Target Single Spin Asymmetry in SIDIS (e, eπ± ) Reaction on
a Transversely Polarized Proton Target and SoLID
Spokespersons: J. P. Chen, Haiyan Gao (Contact), Xiaomei Li (CIAE), Z-E. Meziani (Temple)
PAC38: Conditionally approved
Status on funding applications in China
• National Science foundation of China (NSFC)– Major international collaborations 2-3 M (RMB) over a period of
3-4 years, proposal by Ma and Gao submitted in March 2011, approved in July 2011 for 3M (RMB)
– Another proposal awarded by NSFC 3.5 M (RMB) to B.T. Hu et al.
– Major program, encouraged by NSFC, Z.G. Zhao from USTC will lead the effort
• Ministry of Science and Technology (MOST)– 973 program: large scale science project over a funding period
of 5 years: total ~20M (RMB), proposal submitted March 2011, led by CIAE
(did not make 2nd round this year), will submit March 2012 again
Summary
• Frontiers in nucleon structure go beyond collinear, 1-D picture
– TMDs• Three-dimensional description of nucleon in momentum space
• Direct link with orbital motion (orbital angular momentum)
• Transverse motion: spin-orbit correlations, multi-parton correlations, dynamics of confinement and QCD
• JLab 12-GeV upgrade will provide unique opportunities to map out the 3-dimensional structure of the nucleon, and the SoLID will guarantee this success by JLab
Thanks to many in the SoLID collaboration Supported in part by U.S. Department of Energy under contract number DE-FG02-03ER41231