G. L. Payne

A numerical study of nonlinear Alfvén waves and solitons

Finite‐amplitude Alfven waves can be modeled by a nonlinear wave equation termed the derivative nonlinear Schrodinger equation. A computer program has been developed that solves the derivative nonlinear Schrodinger equation via the ‘‘split‐step’’ Fourier method. This program has been used to investigate a number of topics in the area of nonlinear Alfven waves. When analytic envelope solitons are used as initial conditions, the wave packets propagate without distortion and with the expected speed–amplitude relation. When an arbitrary, amplitude‐modulated wave is used as an initial condition, the results depend strongly on the β of the plasma and the polarization of the wave. For a left circularly polarized wave in a β 1, a collapse instability has been observed in which the wave amplitude increases and modulation scale decreases. For other combinations of polarization and value of β, the wave packet tends to broaden, eliminating the initial modulation.

Triton calculations with the new Nijmegen potentials

Abstract Triton properties are calculated using new nucleon-nucleon potentials, which were fit to the world nucleon-nucleon data. Three of these models have a nearly optimal χ 2 per degree of freedom and can therefore be considered as alternative partial-wave analyses, which in quality can almost compete with the Nijmegen partial-wave analysis. The triton binding energy obtained with three local models (Nijm II, Reid93, AV18) can be summarized as 7.62 ± 0.01 MeV, which is nearly 900 keV lower than experiment. The non-local model Nijm I binds by 7.72 MeV.

Charge symmetry breaking and the two pion exchange two nucleon interaction

Charge-symmetry breaking in the nucleon-nucleon force is investigated within an effective field theory, using a classification of isospin-violating interactions based on power-counting arguments. The relevant charge-symmetry-breaking interactions corresponding to the first two orders in the power counting are discussed, including their effects on the

Scaling relations for triton ground-state observables

{}^{3}\mathrm{He}{\ensuremath{-}}^{3}\mathrm{H}

Thermal n-d radiative capture

binding-energy difference. The static charge-symmetry-breaking potential linear in the nucleon-mass difference is constructed using chiral perturbation theory. Explicit formulas in momentum and configuration spaces are presented. The present work completes previously obtained results.

Charge-symmetry-breaking three-nucleon forces

Abstract Using a wide variety of newly obtained solutions to the Feddeev equations for the triton ground state with diverse two-body and three-body potentials, we have calculated Coulomb energies, RMS charge radii, binding energies, and probabilities of various wave function components. We show how the various radii scale with the corresponding binding energies, and advance simple arguments for the sizes of various wave function components. The Coulomb energies are compared to the hyperspherical approximation, which is found to be very accurate. In addition to our quantitative conclusions, we provide very simple qualitative arguments which account for these conclusions. Comparisons with experimental data are made where applicable.

Nuclear polarizabilities and logarithmic sum rules

Abstract The impulse-approximation and pion-exchange current contributions to the radiative capture of thermal neutrons by deuterium have been calculated using initial- and final-state wave functions generated by solving the configuration-space Faddeev equations for several nucleon-nucleon and nucleon-nucleon-plus-three-body-force hamiltonian models. Numerical results are compared with previously published total cross section data and with recent measurements of the M1 photon polarization and the spin-quartet capture fraction.

Higher-order nuclear-polarizability corrections in atomic hydrogen

Leading-order three-nucleon forces that violate isospin symmetry are calculated in heavy-baryon chiral perturbation theory. The effect of the charge-symmetry-breaking three-nucleon force is investigated in the trinucleon systems using Faddeev calculations. We find that the contribution of this force to the

Higher order nuclear size corrections in atomic hydrogen

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Faddeev Monte-Carlo calculations of trinucleon binding energy with three-body potentials

binding-energy difference is given by