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Electron-deuteron scattering observables, including the tensor polarizations T,o, T,+"T,+"are calculated for a variety of S-N potential models. The main goal is to determine how the tensor polarization experiments can help distinguish competing potential models with respect to off-shell behavior and tensor force strength. The pair meson-exchange-current correction of Gari and Hyuga is included in the analysis as well as a correction suggested by Friar for energy-dependent potentials. It is found that whereas electrondeuteron elastic scattering cross sections do not readily distinguish different potentials, the tensor polarizations do. The tensor polarization T,o mainly distinguishes potentials with different deuteron s-wave momentum distributions, but does not distinguish potentials with different d-state probabilities (PD). The tensor polarization T,+"since it factors essentially into a product of the magnetic and quadrupole form factors, allows for the extraction of the quadrupole form factor which is closely related to the tensor force strength and PD. The tensor polarization T, +, is completely determined by the elastic scattering cross sections and magnetic form factor, and yields no additional information on the N-lV force unobtainable from elastic scattering measurements. The tensor polarizations T,o and T» have maximum values of order unity in the region q = 2 to 5 fm '; The calculations indicate that measurements of T,o for 2&q & 5 fm and T, +, for 3&q &5 fm ' could yield important information on the off-shell behavior and tensor force strength. The meson-exchange-current and energy-dependence corrections are important and must be taken into account to extract potential properties from such experiments.NUCLEAR STHUCTURK H: form factors, tensor polarization calculated: dependence on of'f-shell behavior and &z, seven potential models; pair currents included.

The relativistic three-body equations for the bound-state problem proposed by the authors are solved for the mNN system, in particular for the states with total isospin zero and two. In the case of isospin zero, only one bound state is found which corresponds precisely to the deuteron and whose wave function is quite similar to those of phenomenological models. In the case of isospin two, the most favorable configuration to possess a bound state is with total angular momentum two and positive space parity. There is experimental evidence, however, that the state is unbound; that means that it will appear as a resonance of spin two and isospin two which we call the 4,4 resonance since it is the analog to the we11-known 3,3 resonance in the mN system which has spin z and isospin 2.

Liquid-crystal phases are typical examples of soft and complex materials that exhibit an abundance of different phenomena. In this paper we present some of our results contributing to the understanding of the physics of defects in nematic liquid crystals. The examples presented exhibit many features that are also of interest for other branches of physics. We describe nematic point defects, the annihilation dynamics of a defect and anti-defect pair, and the coarsening dynamics of a dense pattern of defects after a sudden symmetry-breaking phase transition.