15 December 2011 Hall A Meeting

E05-102 Experimental Status Report:

p)e',e(He and d)'e,e(He 33

Vincent A. SulkoskyMassachusetts Institute of Technology

Hall A Collaboration MeetingDecember 15, 2011

15 December 2011 Hall A Meeting

Physics motivation Goal: understanding 3He ground-state spin structure

helps in a variety of experiments that try to extract neutron information from 3He

Theoretically: nucleon-nucleon potential theory predicts three components

in the 3He ground-state wave-function. Understanding the role of the small components of the 3He

ground-state wave function, S’ and D states, helps us understand the “standard model” of the few-body system

Double polarization measurements have large sensitivities to both S’ and D components

15 December 2011 Hall A Meeting

Deuterium Spin Structure

Spin-1 Particle, 2 spin-1/2 Nucleons (Proton and Neutron)

Angular Momentum l=0 l=2 ~90% ~10%

15 December 2011 Hall A Meeting

A sign flip of asymmetry with the increase of missing momentum gave an indication of the existence of D state

Sign flip happened at around Fermi momentum of deuterium nucleus

p)n'e,e(D Asymmetry Measurements at NIKHEF

I. Passchier et al., Phys. Rev. Lett. 88 (2002) 102302.

15 December 2011 Hall A Meeting

3He spin structure Spin-1/2 Particle, 3 spin-1/2 Nucleons (Proton and Neutron) S’ mixed symmetry, (spin-isospin)-space correlations

Angular Momentum l=0 l=0 l=2 ~90% ~1-2% ~8%

EffectivePolarizedNeutronTarget

15 December 2011 Hall A Meeting

Theoretical asymmetry from Faddeev Calculation

15 December 2011 Hall A Meeting

JLab experiment E99-117 measured neutron asymmetry A1

n in the DIS region, the leading error other than statistical is caused by uncertainty in the effective proton and neutron polarization in 3He

New data at (almost) identical Q2 for simultaneously over a broad range of pmiss poses strong constraints on calculations

3He Experiments

X. Zheng et al., Phys. Rev. C 70, 065207(2004)

n)e',e( and p)e',e( d),e',e(

15 December 2011 Hall A Meeting

High Resolution Spectrometer (HRS):detected scattered electrons at 12.5º and 14.5º

BigBite Spectrometer: detected protons and deuterons with large acceptance at 75º and 82º Two wire chambers and two scintillator planes

15 December 2011 Hall A Meeting

3He Target Hybrid K-Rb spin exchange

optical pumping High in-beam polarization:

~ 50-60% Narrow band-width laser

Preliminary

15 December 2011 Hall A Meeting

Separating Protons and Deuterons 1-2% deuterons and rest are protons

15 December 2011 Hall A Meeting

BigBite Optics: Sieve Slit

15 December 2011 Hall A Meeting

BigBite Optics: VertexResolution: 1.6 cm over 40 cm

Results to be submitted to NIM, M. Mihovilovič et al.

15 December 2011 Hall A Meeting

Preliminary Asymmetry Results

Q2 = 0.37 GeV2Q2 = 0.28 GeV2

Preliminary Preliminary

Longitudinal and transverse are with respect to the electron momentum. Work by M. Mihovilovič

15 December 2011 Hall A Meeting

Correct final (minor) bugs in the analysis code regarding considered cuts. Complete analysis of the proton asymmetries. Some of data were not analyzed yet due to a problem with zlib. Do the deuteron analysis with the new analysis scripts. Complete the systematic error analysis (false asymmetry corrections). We expect these corrections to be small. Finalize the target polarization in the scattering chamber.

Need to consider the target orientation corrections, which are expected to be small.

Remaining Tasks

15 December 2011 Hall A Meeting

GEn was extracted for the first time by inclusive

polarized measurements from 3He Getting the ratio of asymmetries in longitudinal

and transverse target polarization; separating the electric and magnetic form factor contributions

Proton and neutron contributions calculated in PWIA

New technique, confirms previous measurements; uncertainty: ~18%, largely statistical

Extraction of GEn at Q2=1 (GeV/c)2

by Measurements of )'e,e(He3

15 December 2011 Hall A Meeting

The ratio of asymmetries as functions of form factors

]))()(2[2

(

])2[2(

'2

'2

2

'

'''

'

'

Tnn

MTpp

MT

TLnn

MnETL

ppM

pETL

T

TL

HGHGqMQv

HGGHGGvAA

By measuring ATL’/AT’ and using GEp, GM

n, and GMn as known

parameters can one extract GEn

15 December 2011 Hall A Meeting

Final result of GEn at Q2=0.95

(GeV/c)2 GEn/GD=0.226±0.041 (stat)±0.016 (syst)

GEn=0.0414±0.0077 (stat)±0.0032 (syst)

Work by Jin Ge

15 December 2011 Hall A Meeting

Summary Deuterium asymmetry: experiment and theories (N-N potential theory) 3He asymmetry: theories but no experiment until JLab experiment E05-102 Analysis ongoing and preliminary results are now available Papers:

NIM article on BigBite Hadron package almost ready Inclusive measurement of GE

n at Q2 ~ 1 (GeV/c)2 draft being edited.

15 December 2011 Hall A Meeting

Graduate StudentsG. Jin, University of Virginia

E. Long, Kent State UniversityM. Mihovilovič, Jožef Stefan Institute

Y. Zhang, Lanzhou University

Run CoordinatorsA. Camsonne, Jefferson Lab

P. Monaghan, Hampton UniversityS. Riordan, University of VirginiaB. Sawatzky, Temple UniversityR. Subedi, University of Virginia

V. Sulkosky, MITY. Qiang, Duke University

B. Zhao, College of William and Mary

S. GolgeO. Hansen

T. HolmstromJ. Huang

H. IbrahimE. JensenM. JonesH. KangJ. Katich

C. W. KeesP. King

J. LeRoseR. Lindgren

H. LuW. Luo

K. AlladaB. AndersonJ. R. M. AnnandW. BoeglinP. BradshawM. CananC. ChenR. De LeoX. DengA. DeurC. DuttaL. El FassiD. FlayF. GaribaldiH. GaoR. Gilman

P. MarkowitzM. MezianeR. Michaels

B. MoffitN. MuangmaH. P. Khanal

K. PanD. Parno

E. PiasetzkyM. Posik

A. J. R. PuckettX. QianX. Qui

A. Saha

Thanks to the Hall A Quasi-ElasticFamily Experiments

SpokespersonsT. Averett, College of William and Mary (E05-015, E08-005)

J. P. Chen, Jefferson Lab (E05-015)S. Gilad, MIT (E05-102)

D. Higinbotham, Jefferson Lab (E05-102, E08-005)X. Jiang, Rutgers University (E05-015)

W. Korsch, University of Kentucky (E05-102)B. E. Norum, University of Virginia (E05-102)

S. Sirca, University of Ljubljana (E05-102)V. Sulkosky, MIT (E08-005)

E05-015,E08-005,and E05-102

Collaboration F. SalvatoreM. ShabestariA. ShahinyanB. Shoenrock

J. St. JohnA. Tobias

W. TiremanG. M. Urciuoli

D. WangK. WangJ. Watson

B. WojtsekhowskiZ. Ye

X. ZhanX. Zheng

L. Zhu

15 December 2011 Hall A Meeting

15 December 2011 Hall A Meeting

Helicity asymmetry in electron scattering

THe

TLHe

L

THe

TTLHe

TL

RvRvRvRvA 33

33

'''' *cos*cos*sin

where R’s are response functions and v’s are kinematics factors

T. D. Donnelly and A. S. Raskin, Ann. Phys 169, 247 (1986)

15 December 2011 Hall A Meeting

Ratio of asymmetries

''

''

'

'

'''

'''

3

3

33

3

33

3

asymmetry allongitudin-e transvers,0* and 2/*when

asymmetry se transver,0*when

THe

T

TLHe

TL

T

TL

THe

TLHe

L

TLHe

TLTL

THe

TLHe

L

THe

TT

RvRv

AA

RvRvRvA

RvRvRvA

15 December 2011 Hall A Meeting

3He inclusive response functions near quasi-elastic peak in PWIA

Transverse-longitudinal:

Transverse:

where H’s are calculated by momentum distribution and nucleon polarization in 3He

A. Kievsky, E. Pace, G. Salme’ and M. Viviani, PRC 56 (1997) p.64

Neutron: Hn Proton: HpT’

Proton: HpTL’

])()(2[2

]2[2

'2

'2

2

'

'''

3

3

Tnn

MTpp

MTHe

TLnn

MnETL

ppM

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He

HGHGqMQR

HGGHGGR