Overview of SoLID: Solenoidal Large Intensity Device for Precision Study

of Nucleon Structure and Test of Standard Model

Nilanga Liyanage, University of Virginia, USA

SoLID Physics Program @ 12 GeV JLab Transverse Spin and Transverse Structure: TMDs Parity Violating DIS J/y and more

SoLID Instrumentation Current Status and Plan SoLID Collaboration

acknowledgement: thanks to Dr. J.P Chen and the SoLID collaboration for some slides and calculations.

• SoLID: large acceptance, capable of handling high luminosity (up to~1039 with baffle, up to ~1037 without baffle)

Ideal for precision Inclusive-DIS (PVDIS) and SIDIS experiments Excellent for selected exclusive reactions (ex. J/Y)

• Five high impact experiments approved: SIDIS: E12-10-006 (3He-T), E12-11-007 (3He-L), E12-11-108 (proton-T) PVDIS: E12-10-007 (deuteron and proton) J/y: E12-12-006

Physics Program for SoLID

SoLID Physics Program (I)

Transverse Spin and Transverse Structure: TMDs

Quark polarization

Unpolarized(U)

Longitudinally Polarized (L)

Transversely Polarized (T)

Nucleon Polarization

U

L

T

Leading-Twist TMD PDFs

f1 =

f 1T =

Sivers

Helicityg1 =

h1 =Transversity

h1 =

Boer-Mulders

h1T =

Pretzelosity

h1L =

Worm Gear

: Survive trans. Momentum integration

Nucleon Spin

Quark Spin

g1T =

Worm Gear

Status of Transverse Spin/Structure Study • Large single spin asymmetry in pp->pX (Fermi, RHIC-spin)• Collins Asymmetries - sizable for the proton (HERMES and COMPASS) large at high x, p- and p+ has opposite sign unfavored Collins fragmentation as large as favored (opposite sign)? - consistent with 0 for the deuteron (COMPASS)• Sivers Asymmetries - non-zero for p+ from proton (HERMES), new COMPASS data - consistent with zero for p- from proton and for all channels from deuteron - large for K+ ? - sign mismatch?• Collins Fragmentation from Belle• Global Fits/models: Anselmino et al., Yuan et al., Pasquini et al., Ma et al., …• TMD evolution, a lot of progress in the last couple years• Very active theoretical and experimental efforts

JLab (6 GeV and 12 GeV), RHIC-spin, Belle, FAIR, J-PARC, EIC, …• First neutron measurement from Hall A 6 GeV (E06-010)• SoLID with polarized p and n(3He) at JLab 12 GeV Unprecedented precision with high luminosity and large acceptance

COMPASS Sivers asymmetry 2010 datax > 0.032 region - comparison with HERMES results

New high-xbjResults (II) from JLab Hall A E06-010 with a Transversely Polarized 3He (n)

Results on Neutron

Collinsasymmetries are not large, except at x=0.34

Sivers negative

Blue band: model (fitting) uncertainties Red band: other systematic uncertainties

• • Corrected for proton dilution, fp

• Predicted proton asymmetry contribution < 1.5% (π+), 0.6% (π-)•

• Dominated by L=0 (S) and L=1 (P) interference• Consist w/ model in signs, suggest larger asymmetry

Neutron ALT Extraction

hq

qT

n DgA 11LT Trans-helicity

Extracted Results on NeutronExtracted Pretzelosity Asymmetries, For both p+ and p-, consistent with zero within uncertainties.

Preliminary Results

Preliminary K+/K- Collins and Sivers Asymmetries on 3He

JLab 12 GeV Era: Precision Study of TMDs

• From exploration to precision study with 12 GeV JLab• Transversity: fundamental PDFs, tensor charge• TMDs: 3-d momentum structure of the nucleon• Quark orbital angular momentum• Multi-dimensional mapping of TMDs

• 4-d (x,z,P┴,Q2) • Multi-facilities, global effort

• Precision high statistics• high luminosity and large acceptance

Nucleon Structure (TMDs) with SoLID Semi-inclusive Deep Inelastic Scattering program: Large Acceptance + High Luminosity+ Polarized targets 4-D mapping of asymmetries Tensor charge, TMDs …Lattice QCD, QCD Dynamics, Models.

International collaboration (8 countries,50+ institutes and 190+ collaborators)• Rapid Growth in US China Collaboration‐

Solenoidal Large Intensity Device (SoLID)

Mapping of Collins/Siver Asymmetries with SoLID

E12-10-006 3He(n), Spokespersons: J. P. Chen, H. Gao, X. Jiang, J-C. Peng, X. QianE12-11-007(p) , Spokespersons: K. Allda, J. P. Chen, H. Gao, X. Li, Z-E. Mezinai

• Both p+ and p-• Precision Map

in region x(0.05-0.65)

z(0.3-0.7) Q2(1-8) PT(0-1.6)

• <10% u/d quark tensor charge

Expected Improvement: Sivers Function

• Significant Improvement in the valence quark (high-x) region• Illustrated in a model fit (from A. Prokudin)

f 1T =

E12-11-107: Worm-gear functions Spokespersons: J. P. Chen/J. Huang/Y. Qiang/ W. Yan

• Dominated by real part of interference between L=0 (S) and L=1 (P) states

• No GPD correspondence• Lattice QCD -> Dipole Shift in mom. space.• Model Calculations -> h1L

=? -g1T .

h1L =

g1T =

Longi-transversityTrans-helicity

Cent

er o

f poi

nts:

)()(~ 11 zDxgA TLT )()(~ 11 zHxhA LUL

Measure Transversity via Dihadron with SoLID LOI to JLab PAC 40, J. Zhang, J. P. Chen, A. Courtoy, H. Gao

Wide xb and Q2 coverages

Projected Statistics error for one (Mpp,zpp) bin, integrated over all y and Q2.

• Precision dihadron (p+/p-) production on a transversely polarized 3He (n) • Extract transversity on neutron• Provide crucial inputs for flavor separation of transversity

Discussion• Unprecedented precision 4-d mapping of SSA

• Collins and Sivers• Study factorization with x and z-dependences • Study PT dependence• Combining with the world data

• extract transversity and fragmentation functions for both u and d quarks• determine tensor charges• study TMDs in the valence region • study quark orbital angular momentum• study Q2 evolution

• Global efforts (experimentalists and theorists), global analysis• much better understanding of multi-d nucleon structure and QCD

• Long-term future: EIC to map sea and gluon SSAs

SoLID Physics Program (II)Parity Violating Deep Inelastic Scattering

Precision Test of Standard Model and Precision Study of Hadron Properties

Parity Violating Deep Inelastic Scattering (PVDIS)

A

V

V

A

• Especially good way to access hadronic axial vector currents, the term; in nucleon PV experiments large theoretical uncertainty due to electroweak radiative corrections, but in PVDIS scattering is off isolated quarks and these corrections are calculable.

• Iso-scaler targets like deuterium are nice because most hadronic corrections cancel.

• At x > 0.4 only valance quarks are important

PVDIS with SoLID: E12-10-007: Spokespersons : Souder, Reimer, Liyanage

• High Luminosity on LD2 and LH2 • Better than 1% errors for small bins

over large range kinematics• Test of Standard Model • Quark structure: charge symmetry violation quark-gluon correlations

d/u at large-x

12 GeV PVDIS Sensitivity: C1 and C2 Plots

Cs

PVDIS

Qweak PVDIS

World’s data

Precision Data

6 GeV

QCD: Charge Symmetry Violation

We already know CSV exists:• u-d mass difference δm = md-mu ≈ 4 MeV

δM = Mn-Mp ≈ 1.3 MeV• electromagnetic effects

• Direct observation of CSV—very exciting!• Important implications for PDF’s• Could be a partial explanation of the NuTeV anomaly

For APV in electron-2H DIS:

Broad χ2 minimum

(90% CL)

MRST PDF global with fit of CSVMartin, Roberts, Stirling, Thorne Eur Phys J C35,

325 (04)

MRST (2004)

QCD: Higher Twist

From the Quark Parton Model (QPM) to QCD1.Add DGLAP evolution2.Add higher order terms in the Operator Product Expansion (OPE)↔Higher Twist Terms

Parton Model—leading twist

Di-quarks

Quark-gluondiagram

What is a truequark-gluonoperator?

Quark-gluon operatorscorrespond to

transverse momentum

QCD equationsof motion

QCD:Higher Twist--MRST Fits

x Q2min

D(x) D/Q2min (%)

LO N3LO LO N3LO

0.1-0.2 0.5 -.007 0.001 -14 2

0.2-0.3 1.0 -.11 0.003 -11 0.0

0.3-0.4 1.7 -.06 -0.001 -3.5 -0.5

0.4-0.5 2.6 .22 0.11 8 4

0.5-0.6 3.8 .85 0.39 22 10

0.6-0.7 5.8 2.6 1.4 45 24

0.7-0.8 9.4 7.3 4.4 78 47

F2(x,Q2)=F2(x)(1+D(x)/Q2) Q2=(W2-M2)/(1/x-1) Q2min=Q2(W=2)

MRST, PLB582, 222 (04)

Higher twistfalls slowly

compared to PDF’s

at large x.

Order of DGLAPinfluences size

of HT

If C(x)~D(x), there is largesensitivity al large x.

Coherent Program of PVDIS StudyStrategy: requires precise kinematics and broad range

x Y Q2

New Physics no yes noCSV yes no noHigher Twist yes no yes

Fit data to:

Measure Ad in narrow bins of x, Q2 with 0.5% precision Cover broad Q2 range for x in [0.3,0.6] to constrain HT Search for CSV with x dependence of Ad at high x Use x > 0.4, high Q2 to measure a combination of the Ciq’s

GEM

EM Calorimeter(forward angle)

GEM

Cherenkov

Baffle

Target

CLEO II Coil and Yoke

SoLID PVDIS Configuration

Statistical Errors (%) vs. Kinematics

4 months at 11 GeV

2 months at 6.6 GeV

Error bar σA/A(%) shown at center of bins in Q2, x

Statistical sensitivity for SOLID spectrometer

PVDIS on the Proton: d/u at High x

Deuteron analysis has largenuclear corrections (Yellow)

APV for the proton has no such corrections

(complementary to BONUS/MARATHON)

)(25.0)()(91.0)()(

xdxuxdxuxaP

++

3-month run

SoLID-J/y: Study Non-Perturbative Gluons

Quark Energy

Trace Anomaly

Gluon Energy

Quark Mass

50 days @ 1037 N/cm2/s

* /N N J y+ +

J/ψ: ideal probe of non-perturbative gluon

The high luminosity & large acceptance capability of SoLID enables a unique “precision” measurement near threshold

• Search for threshold enhancement• Shed light on the conformal anomaly

G G

X. Ji PRL 74 1071 (1995)

Zhiwen Zhao

SoLID Instrumentation

Magnet, Detectors, DAQs, Simulations

SoLID Instrumentation

Magnet options studied: (UVa+Argonne+JLab) First narrowed from 6 options to 2, CLEO/BaBar/CDF/ZEUS/Glue-X/New

CLEO or BaBarBoth satisfy needs, both available

Talked to both parties, obtained informationDetailed discussion with CLEOField study, force study, Engineering study, including cost estimation Site visit

CLEO was chosen

Discussion with DOE Position paper sent to DOE, just got favorable

response

Will move the magnet to JLab in 2014/2015 Refurbish

Solenoidal Magnet

Tracking: GEMs: Five Chinese groups+ US side: UVa/Temple Conceptual design mostly complete R&D on-going, together with SuperBigBite, EIC projects

e/pi separation (I) Electromagnetic Calorimeter (UVa+Los Almos+ W&M)

COMPASS style Shashlyk calorimeter e/pi separation (II) light gas Cherenkov (Temple)

Magnetic field effect, performance studied, in-beam test Conceptual design complete, supporting structure

pi/K separation (I) heavy gas Cherenkov (Duke) Field effect, performance studied Conceptual design complete, supporting structure

pi/K separation(II) MRPC (Tsinghua) In-beam test, publication

Detectors: Overview

SoLID in Hall A

• Strong International Collaboration: 8 countries, 50+ institutes and 190+ collaborators10 Chinese institutions, contribute to GEMs (5), MRPC

• Magnet: CLEO magnet chosen, engineering study, position paper to DOE

• Simulations: full package with GEANT4, physics, background, neutrons, detector design, …

• Detectors: “finalized” conceptual designlight Cherenkov, heavy Cherenkov, GEMs, MRPCcalorimeters (shashlyk), forward and large-angle

• Baffle, DAQ • Targets, Beam Polarimetry• Director’s review: early fall, charge available• 1st draft of Pre-Conceptual Design Report ready• Schedule: review/MIE 2013, DOE approval (CD) process 2013-

2015, construction 2016-2018, experiments starts in 2018?

great opportunities for new groups / young people

SoLID Status and Plan

Summary• A challenge: Understand Strong QCD

• New development: direct comparison of experiments with theory• Needs multi (transverse) dimension • Needs precision: high luminosity and large acceptance

• SoLID @ JLab 12 GeV: exciting physics program 4 “A” rated, 1 “A-” rated experiments approved

• SIDIS: Precision extraction of transversity/tensor charge/ TMDs• PVDIS: low energy test of standard model and hadron properties• J/y threshold production: study gluons• LOIs/Future proposals (di-hadron, TCS)

• Exciting new opportunities lead to breakthroughs?• New collaborators welcome