Ingo Sick

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We study the world data on elastic electron-proton scattering in order to determine the proton charge rms-radius. After accounting for the Coulomb distortion and using a parameterization that allows to deal properly with the higher moments we find a radius of 0.895 ± 0.018f m, which is significantly larger than the radii used in the past.
The neutron charge form factor G En (q) is determined from an analysis of the deuteron quadrupole form factor F C2 (q) data. Recent calculations, based on a variety of different model interactions and currents, indicate that the contributions associated with the uncertain two-body operators of shorter range are relatively small for F C2 (q), even at large(More)
In order to achieve better accuracy on the measurement of electron beam polarization employing e'-e' scattering, we have developed an improved polarized electron target. Using a pure iron foil saturated out-of-plane in a 4 T magnetic field one can reduce the systematical errors to the promille level. Measurement of the relative target polarization using(More)
We determine the Zemach moments of hydrogen and deuterium for the first time using only the world data on elastic electron-proton and electron-deuteron scattering. Such moments are required for the calculation of the nuclear corrections to the hyperfine structure of these hydrogenic atoms. We compare the resulting HFS predictions to the available(More)
We propose to extend our previous measurements of G n E from deuterium to Q 2 = 6.88 (GeV/c) 2. Additional measurements at 5.22, 3.95, and 2.18 (GeV/c) 2 will provide continuity with our prior measurements up to Q 2 = 1.45 (GeV/c) 2 , and overlap with recent (unpublished) measurements from a polarized 3 He target. The JLab E93-038 collaboration measured G n(More)
This article presents a review of the field of inclusive quasi-elastic electron-nucleus scattering. It discusses the approach used to measure the data and includes a compilation of data available in numerical form. The theoretical approaches used to interpret the data are presented. A number of results obtained from the comparison between experiment and(More)
Ground-state hyperfine splittings in hydrogen and muonium are very well measured. Their difference, after correcting for magnetic moment and reduced mass effects, is due solely to proton structure-the large QED contributions for a pointlike nucleus essentially cancel. The rescaled hyperfine difference depends on the Zemach radius, a fundamental measure of(More)
We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable(More)
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