Elastic electron deuteron scattering with consistent meson exchange and relativistic contributions of leading order

The influence of relativistic contributions to elastic electron deuteron scattering is studied systematically at low and intermediate momentum transfers ($Q^2\leq 30$ fm$^{-2}$). In a $(p/M)$-expansion, all leading order relativistic $\pi$-exchange contributions consistent with the Bonn OBEPQ models are included. In addition, static heavy meson exchange currents including boost terms and lowest order $\rho\pi\gamma$-currents are considered. Sizeable effects from the various relativistic two-body contributions, mainly from $\pi$-exchange, have been found in form factors, structure functions and the tensor polarization $T_{20}$. Furthermore, static properties, viz. magnetic dipole and charge quadrupole moments and the mean square charge radius are evaluated.Comment: 15 pages Latex including 5 figures, final version accepted for publication in Phys.Rev.C Details of changes: (i) The notation of the curves in Figs. 1 and 2 have been clarified with respect to left and right panels. (ii) In Figs. 3 and 4 an experimental point for T_20 has been added and a corresponding reference [48] (iii) At the end of the text we have added a paragraph concerning the quality of the Bonn OBEPQ potential

TESTS OF DYNAMICS THROUGH POLARIZATION EXPERIMENTS : THE CASE OF THE DIBARYON

Nous présentons une revue du formalisme optimal pour relier les amplitudes et les observables dans la diffusion à deux corps. Ce formalisme est appliqué au problème de la détermination complète d'ensembles non ambigüs d'amplitudes ; il conduit au fait que le vecteur polarisation est superflu pour déterminer des amplitudes du deuteron et au fait que des états dibaryon singlet et triplet sont plausibles dans la diffusion élastique p-p.The Optimal Formalism for relating amplitudes and observables in two-body scattering is reviewed. It is applied to : the problem of determining complete unambiguous sets of amplitudes ; the redundancy of vector polarization for determining deuteron amplitudes ; the plausibility of singlet and triplet dibaryon states in p-p elastic scattering

Interfacing theory and experiment in polarization studies

The results pertain to any particle reaction in atomic, nuclear, or high energy physics, and deal with some of the general properties of such reactions. A formalism for discussing polarization experiments in such reactions is suggested in which appropriately chosen reaction amplitudes are directly related to quantities actually measured in experiments, thus making the connections between theory and experiment as simple as possible and eliminating intermediary quantities between theory and experiment. It is proven that such direct experimental observables along two quantization directions always suffice in completely determining the amplitudes from experimental data. It is also shown that given a specific theoretical model prediction for the reaction amplitudes in any formulation, one can always find a quantization direction such that the measurement of the number of particles in one single projection state with respect to that quantization direction forms a null experiment to test the theoretical prediction. Three examples of particle reactions are worked out in detail to illustrate the problem and the suggested formalism. In the concluding section the main results are summarized and their implications are discussed with respect to the design of experiments and the interfacing of theories with experimental verirication. 12 references

EXPLORING DYNAMICS THROUGH POLARIZATION

Nous présentons une revue du formalisme optimal qui est appliqué à la détermination de plusieurs amplitudes à partir des observables de la diffusion pp élastique. Un modèle de Regge élaboré ne réussit pas à expliquer ces amplitudes, mais le schéma OPE reste valable. On trouve une étonnante simplification dans le repère "de côté". Nous considérons la pertinence de QCD.The Optimal Formalism is reviewed and applied to determining various amplitudes form observables in pp elastic scattering. A sophisticated Regge model fails to explain these amplitudes, but OPE remains valid. Striking simplicity is found in the "sidewise" frame. The relevance of QCD is considered