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
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'''
'
'
Tnn
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TLnn
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TL
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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
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asymmetry allongitudin-e transvers,0* and 2/*when
asymmetry se transver,0*when
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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’
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