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

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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

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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 <jinhuang@jlab.org> 7

TMDs in SIDIS Cross Section

...]})3sin(

...)()sin(

)sin([

...])cos(1[

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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 <jinhuang@jlab.org> 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 <jinhuang@jlab.org> 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 <jinhuang@jlab.org> 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