Extraction of the neutron electric form factor from measurements of inclusive double spin asymmetries (original) (raw)
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Physical Review Letters, 2010
The electric form factor of the neutron was determined from studies of the reaction 3He→(e→,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find GEn=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q2=1.72, 2.48, and 3.41GeV2, respectively.
Physical review letters, 2013
A measurement of beam helicity asymmetries in the reaction 3He[over →](e[over →],e'n)pp is performed at the Mainz Microtron in quasielastic kinematics to determine the electric to magnetic form factor ratio of the neutron GEn/GMn at a four-momentum transfer Q2=1.58 GeV2. Longitudinally polarized electrons are scattered on a highly polarized 3He gas target. The scattered electrons are detected with a high-resolution magnetic spectrometer, and the ejected neutrons are detected with a dedicated neutron detector composed of scintillator bars. To reduce systematic errors, data are taken for four different target polarization orientations allowing the determination of GEn/GMn from a double ratio. We find μnGEn/GMn=0.250±0.058(stat)±0.017(syst).
2003
A high precision measurement of the transverse spin-dependent asymmetry A T Ј in 3 He ជ (e ជ ,eЈ) quasielastic scattering was performed in Hall A at Jefferson Lab at values of the squared four-momentum transfer, Q 2 , between 0.1 and 0.6 (GeV/c) 2 . A T Ј is sensitive to the neutron magnetic form factor, G M n . Values of G M n at Q 2 ϭ0.1 and 0.2 (GeV/c) 2 , extracted using Faddeev calculations, were reported previously. Here, we report the extraction of G M n for the remaining Q 2 values in the range from 0.3 to 0.6 (GeV/c) 2 using a plane-wave impulse approximation calculation. The results are in good agreement with recent precision data from experiments using a deuterium target.
Physical Review C, 2003
A high precision measurement of the transverse spin-dependent asymmetry A T Ј in 3 He ជ (e ជ ,eЈ) quasielastic scattering was performed in Hall A at Jefferson Lab at values of the squared four-momentum transfer, Q 2 , between 0.1 and 0.6 (GeV/c) 2 . A T Ј is sensitive to the neutron magnetic form factor, G M n . Values of G M n at Q 2 ϭ0.1 and 0.2 (GeV/c) 2 , extracted using Faddeev calculations, were reported previously. Here, we report the extraction of G M n for the remaining Q 2 values in the range from 0.3 to 0.6 (GeV/c) 2 using a plane-wave impulse approximation calculation. The results are in good agreement with recent precision data from experiments using a deuterium target.
Measurement of the electric form factor of the neutron at Q2 = 0.3-0.8 (GeV/ c) 2 ⋆
The European Physical Journal A, 2005
The electric form factor of the neutron, GE,n, has been measured at the Mainz Microtron by recoil polarimetry in the quasielastic D( e, e ′ n)p reaction. Three data points have been extracted at squared four-momentum transfers Q 2 = 0.3, 0.6 and 0.8 (GeV/c) 2 . Corrections for nuclear binding effects have been applied. PACS. 13.40.Gp Electromagnetic form factors -14.20.Dh Protons and neutrons -13.88.+e Polarisation in interactions and scattering
Measurement of the Proton Form Factor Ratio GE/GM from Double Spin Asymmetries
2011
Experiment E03-109 (SANE, Spin Asymmetries of the Nucleon Experiment) was carried out in Hall C at Jefferson Lab to study the proton spin structure functions with a dynamically polarized ammonia target and longitudinally polarized electron beam. Scattered electrons were detected by the Big Electron Telescope Array (BETA), and a set of elastic data was collected by detecting the recoiling proton in the High Momentum Spectrometer (HMS) in coincidence with the electron. The measurement of the elastic double spin asymmetry allows to extract the proton electric to magnetic form factor ratio GE/GM at high four-momentum transfers, Q^2 = 5.25 (GeV/c)^2 and Q^2 = 6.25 (GeV/c)^2. In addition to the coincidence data, inclusively scattered electrons from the polarized ammonia target were detected by HMS, which allows to extract GE/GM from the beam-target asymmetry in the elastic region at lower four-momentum transfer, Q^2 = 2.2 (GeV/c)^2. These alternative measurements of GE/GM will verify the ...