0000000000542417
AUTHOR
R. Sprengard
First measurement of the polarisation transfer on the proton in the reactions $$H(\vec e,e'\vec p)$$ and $$D(\vec e,e'\vec p)$$
The measurement of the polarisation transfer to the proton in the reactions\(H(\vec e,e'\vec p)\) and\(D(\vec e,e'\vec p)\) performed with longitudinally polarised electrons in quasi-free kinematics is presented. The coincidence measurement was executed atQ2≈8fm−2 using the 855 MeV, c.w. beam of the Mainz Microtron MAMI. The recoil polarisation was determined by means of a carbon analyser. The experiment shows that the binding of the nucleon does not modify the polarisationPx of the recoil proton within an error ofΔPx/Px≈10%. The measured polarisation agrees with recent theoretical predictions. Implications for the measurement of the electric form factor of the neutron using the\(D(\vec e,e…
Determination of the neutron electric form factor in the D(e,e′n)p reaction and the influence of nuclear binding
The electric form factor of the neutron GE,n has been determined at the Mainz Microtron MAMI at the low momentum transfer Q2= 0.15 (GeV/c)2 in a measurement of the recoil polarisation ratio Px/Pz in the quasifree reaction D(e,e′n)p. At this Q2 the influence of the nuclear binding is strong. A purely kinematical model is used to get some insight into the effect of the initial Fermi momentum distribution of the neutron. The influence of the final state interaction is determined quantitatively by a model of Arenhovel et al.. After the corresponding corrections a value of GE,n(0.15 (GeV/c)2) = 0.0481±0.0065stat±0.0053syst is obtained.
Determination of the neutron electric form factor from the reaction 3 He(e,e'n) at medium momentum transfer
The electric form factor of the neutron GEn has been determined in double polarized exclusive 3He(e,e'n) scattering in quasi–elastic kinematics by measuring asymmetries A⊥, A∥ of the cross section with respect to helicity reversal of the electron, with the nuclear spin being oriented perpendicular to the momentum transfer q in case of A⊥ and parallel in case of A∥. The experiment was performed at the 855 MeV c. w. microtron MAMI at Mainz. The degree of polarization of the electron beam and of the gaseous 3He target were each about 50%. Scattered electrons and neutrons were detected in coincidence by detector arrays covering large solid angles. Quasi–elastic scattering events were reconstruc…
On the interpretation of the experimental Raman spectrum of β-eucryptite LiAlSiO4 from atomistic computer modeling
Abstract The vibrational spectrum of β-eucryptite LiAlSiO4 with stuffed high quartz structure – commercially relevant for zero-expansion glass ceramics – was calculated by lattice energy minimization and diagonalization of the dynamical matrix using an ab initio based ion-pair shell model potential. A full symmetry analysis of the vibrational modes was carried out. Raman activity of vibrations was calculated under parameterization of individual polarizability factors for each type of interatomic bonds in β-eucryptite LiAlSiO4. Calculated vibrational energies agree with the experimental energies within ±2.3%. Agreement of calculated spectroscopic Raman intensities with experimental intensiti…
"Table 1" of "First measurement of the polarization transfer on the proton in the reactions H (e (polarized), e-prime p (polarized)) and D (e (polarized), e-prime p (polarized))"
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