Measurements of three vector-to-vector and seven vector-to-tensor polarization transfer coefficients of the 2H1H elastic scattering at Ep = 10 MeV are reported in the angular range between θcm = 92° and 180°. These second-order observ are compared with Faddeev calculations. It is shown that the vector-to-tensor components depend largely on the details of the N-N P-wave interaction.
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After a brief historic overview the basic equations for three-nucleon (3N) scattering based on general two-nucleon and 3N forces are reviewed and the main steps for their derivation are given. Also the expressions for the various observables, elastic and breakup cross sections, as well as the great variety of spin observables are displayed and derived. The treatment of the 3N Faddeev equations in momentum space and in a partial wave decomposition is outlaid in some detail, the handling of the singularities in the integral kernel described and the algorithms and techniques used to solve the large set of equations in the discretized form are presented. Accuracy tests in form of benchmark calculations, where our results are compared to the ones of other techniques, are given. The bulk part of this review, however, is devoted to the comparison of very many observables in elastic nucleon-deuteron (Nd) scattering and the breakup process to the predictions based on the most modern nucleon-nucleon (NN) forces AV18, Nijmegen93, Nijmegen I and II and a recently updated OBE-potential CD Bonn. Overall the agreement with the data is excellent and there is little room left for the action of a three-nucleon force (3NF). The effects of the π-π, π-ϱ and ϱ-ϱ exchange 3NF's of the Tucson-Melbourne model are studied. They are in general small and in the few cases where discrepancies to data occur using NN forces only, they go into the wrong direction. We propose quite a few measurements, which should help to get more information on the potential energy of three nucleons. Several special topics are discussed: Do certain 3N scattering observables scale with the triton binding energy? Which of the 3N breakup cross sections are totally insensitive to the choice of the NN force and which are very sensitive? How well can one extract the nn scattering length from the 3N breakup? We discuss the outsticking discrepancy of the 3N analyzing power Ay in low energy elastic Nd scattering; the eigen phase shifts and mixing parameters in elastic nd scattering; the simplifications of 3N scattering at high energies and the formulation of the optical potential for elastic nd scattering and its limiting form at high energies. Alternative approaches to solve 3N scattering: in configuration space, using finite rank expansions of NN forces, variational techniques and the hybrid Sendai method are briefly described as well as the proton proton Coulomb force problem in the pd system and the question how to incorporate relativity. Finally some applications are sketched where a 3N final state occurs and where the interaction among the nucleons requires a correct treatment. We mention inelastic electron scattering as well as π-absorption on 3He (3H) and nonmesonic decay of the hypertriton.
Rigorous Faddeev three-nucleon continuum calculations were performed with meson based two-nucleon interactions. All partial wave force components with two-body total angular momenta j⩽ 3 were included. Predictions of the Paris and the new Bonn (OBEPQ) potentials for first- and second-order (polarization transfer coefficients) observables in neutron-deuteron elastic scattering are compared with a nearly complete experimental set of pd data taken at Ec.m. = 6.66 MeV. Definite discrepancies between experiment and theoretical prediction for the vector analysing powers Aγ and iT11, were found. Observables sensitive to the 3S1–3D1 tensor and 3P-wave forces are indicated. Further experiments are proposed.
Rigorous Faddeev calculations of the cross sections and analysing powers for elastic nd scattering at En = 10.0, 12.0, 13.0 and 14.1 MeV were made. As two-nucleon interactions we used the Paris potential and two OBE-parametrizations of the new Bonn potential. The nucleon-nucleon interaction was assumed to act in all partial waves with total angular momentum j⩽2. The influence of higher partial waves (j = 3) and the charge dependence of the NN interaction in the 1S0 wave were studied. Definite discrepancies between experiment and theoretical prediction for the neutron analysing powers were found.
Angular distributions of the cross section, analyzing powers and polarization transfer coefficients of pd elastic scattering have been measured at a proton laboratory energy of 10 MeV. Of the 23 determined observables 19 quantities are independent and constitute a nearly complete experiment. They provide information on different aspects of the NN interaction. The data set is compared with Faddeev calculations using an NN interaction in a separable representation. Excellent to satisfactory agreement is observed for most observables. No basic objections could be found for the use of separable potentials, considering the on- and off-shell behaviour and the sensitivity of the measured quantities.
A survey is presented concerning recent polarization experiments in the elastic p-d, p-3He, and p-4He systems. Mention is made of selected neutron experiments. The nominal energy range is 10 to 1000 MeV. Recent results and interpretations of the p-d system near 10 MeV are discussed. New experiments on the energy dependence of back angle p-d tensor polarization are discussed with respect to resolution of discrepancies and difficulty of theoretical interpretation. Progress is noted concerning multiple scattering interpretation of forward p-d deuteron polarization. Some new results are presented concerning the p-3He system and higher energy p-4He polarization experiments.
Measurements are reported of the spin correlation parameter Cy,y for the elastic scattering of 10.0 MeV vector polarized deuterons from a polarized proton target at five CM angles (76°, 85°, 98°, 115°, 132°). The experimental results are compared with different predictions. A Faddeev type calculation on the basis of local potentials also including approximate Coulomb distortion is favoured by our experimental results.
