Selectivity of the Nucleon Induced Deuteron Breakup and Relativistic Effects

Theoretical predictions for the nucleon induced deuteron breakup process based on solutions of the three-nucleon Faddeev equation including such relativistic features as the relativistic kinematics and boost effects are presented. Large changes of the breakup cross section in some complete configurations are found at higher energies. The predicted relativistic effects, which are mostly of dynamical origin, seem to be supported by existing data.Comment: 4 pages, 4 figure

Can the magnetic moment contribution explain the A_y puzzle?

We evaluate the full one-photon-exchange Born amplitude for $Nd$ scattering. We include the contributions due to the magnetic moment of the proton or neutron, and the magnetic moment and quadrupole moment of the deuteron. It is found that the inclusion of the magnetic-moment interaction in the theoretical description of the $Nd$ scattering observables cannot resolve the long-standing $A_y$ puzzle.Comment: 7 pages, 2 Postscript figures; to appear in Phys.Rev.

3N Scattering in a Three-Dimensional Operator Formulation

A recently developed formulation for a direct treatment of the equations for two- and three-nucleon bound states as set of coupled equations of scalar functions depending only on vector momenta is extended to three-nucleon scattering. Starting from the spin-momentum dependence occurring as scalar products in two- and three-nucleon forces together with other scalar functions, we present the Faddeev multiple scattering series in which order by order the spin-degrees can be treated analytically leading to 3D integrations over scalar functions depending on momentum vectors only. Such formulation is especially important in view of awaiting extension of 3N Faddeev calculations to projectile energies above the pion production threshold and applications of chiral perturbation theory 3N forces, which are to be most efficiently treated directly in such three-dimensional formulation without having to expand these forces into a partial wave basis.Comment: 25 pages, 0 figure

Relativistic effects in exclusive neutron-deuteron breakup

We extended the study of relativistic effects in neutron-deuteron scattering to the exclusive breakup. To this aim we solved the three-nucleon Faddeev equation including such relativistic features as relativistic kinematics and boost effects at incoming neutron lab. energies E_n^{lab}=65 MeV, 156 MeV and 200 MeV. As dynamical input a relativistic nucleon-nucleon interaction exactly on-shell equivalent to the CD Bonn potential has been used. We found that the magnitude of relativistic effects increases with the incoming neutron energy and, depending on the phase-space region, relativity can increase as well as decrease the nonrelativistic breakup cross section. In some regions of the breakup phase-space dynamical boost effects are important. For a number of measured exclusive cross sections relativity seems to improve the description of data.Comment: 27 pages, 4 png figures and 7 ps figure

Spin and dynamics in relativistic quantum theories

The role of relativity and dynamics in defining the spin and orbital angular momentum content of hadronic systems is discussed.Comment: 7 pages, proceedings for Light Cone 2014, Raleigh, N

A New Look into the Partial Wave Decomposition of Three-Nucleon Forces

We demonstrate that the partial wave decomposition of three-nucleon forces used up to now in momentum space has to be necessarily unstable at high partial waves. This does not affect the applications performed up to now, which were restricted to low partial waves. We present a new way to perform the partial wave decomposition which is free of that defect. This is exemplified for the most often used $2\pi$-exchange Tuscon-Melbourne three-nucleon force. For the lower partial waves the results of the old method are reproduced.Comment: 38 pages in REVTeX, 4 figures in PiCTe

Benchmark calculations for polarization observables in 3N scattering

High precision benchmark calculations for phase-shifts and mixing parameters as well as observables in elastic neutron-deuteron scattering below the deuteron breakup threshold are presented using a realistic nucleon-nucleon potential. Two totally different methods, one using a variational principle in configuration space and the other solving the Faddeev equations in momentum space are used and compared to each other. The agreement achieved in phase-shifts and mixing parameters as well as in the polarization observables is excellent. The extreme sensitivity of the vector analyzing power Ay to small changes of the phase shifts and mixing parameters is pointed out.Comment: 22 pages, 5 postscript figure

Spin in relativistic quantum theory

We discuss the role of spin in Poincar\'e invariant formulations of quantum mechanics.Comment: 54 page

Scaling properties of the longitudinal and transversal asymmetries of the n⃗d⃗\vec{n}\vec{d} total cross section

The longitudinal and transversal asymmetries of the total $\vec{n}\vec{d}$ cross section are calculated. Four modern nucleon-nucleon interactions: AV18, CD Bonn, NijmI and NijmII, give different predictions for these observables. When the three-nucleon Hamiltonian is supplemented by the $2\pi$-exchange Tucson-Melbourne three-nucleon force (3NF), individually adjusted with each particular NN potential to reproduce the experimental triton binding energy, all predictions practically coincide. We propose to check this scaling behavior experimentally in order to get a clear signal for 3NF effects in the low energy three-nucleon continuum. Connected to that is the proposal to measure the energy at which the longitudinal asymmetry goes through zero. This energy is shifted by about 400 keV when 3NF's are acting.Comment: 8 pages in RevTeX, 2 postscript figure

The six-nucleon Yakubovsky equations for 6He

The six-nucleon problem for the bound state is formulated in the Yakubovsky scheme. Hints for a numerical implementation are provided.Comment: 25 pages, 0 figure