Y.E. Kim

Meson-exchange currents and 3H, 3He magnetic moments

Abstract It is shown that the discrepancies between the experimental 3 H, 3 He magnetic moments and single-particle values are very nearly accounted for by two-nucleon one-pion-exchange contributions. About two thirds of the discrepancy in the isovector magnetic moment is given by trinucleon S-D matrix elements.

Extended parameterization of nuclear-reaction cross sections for few-nucleon nuclei

We present a series of extended parametric fits to the S-factors and, therefore, the cross sections, for the light-nuclei fusion reactions D(D, p)T, D(D, n)3He, 3He(D, p)4He and T(D, n)4He. These fits constitute a family of continuous functions valid over a very wide range of energies (∼ 0 to ∼50 MeV) that may be used in reaction-rate and other calculations involving these reactions. Thus, they have a much more extended range of applicability compared to previous similar fits.

Calculation of meson-exchange corrections to triton beta decay using realistic nuclear wave functions

Abstract The one-pion-exchange contribution to the axial-vector matrix element for 3 H → 3 He + e − + g n e is calculated. The model of Cheng, based on CVC and PCAC, is used to determine the corrections to the axial-vector operator, and trinucleon wave functions are calculated by solving the Faddeev equations for the Reid soft-core nucleon-nucleon potential. The S-D transition matrix elements give the dominant contributions in agreement with previous results of Blomqvist and of Riska and Brown.

Current conservation, meson-exchange currents, and magnetic form factors of 3He and 3H

Abstract The effect of the requirement of current conservation for meson-exchange currents containing the πNN form factor is investigated for the magnetic form factors of 3 He and 3 H. The effect is substantial for the pionic current contribution but is small for the total contribution to the momentum transfer, Q ≲ 5 fm −1 .

Proton-deuteron radiative capture and the two-body photodisintegration of 3He

Abstract We investigate the two-body photodisintegration of 3 He and its inverse, radiative p-d capture using bound-state functions corresponding to the N-N interaction being given by the Reid soft-core potential. For the two-body photodisintegration of 3 He Coulomb effects and the final-state interactions between the proton and deuteron are not included. At low energy the shape of the angular distribution agrees well with experiment, but the 90° cross section exhibits an anomalous peak at 15 MeV due to electric dipole transitions connecting the deuteron and 3 He D-states. The low-energy cross section is 25–40 % too small. The intermediate-energy angular distribution peaks too near the forward direction, and, contrary to experiment, has a minimum at 100°. At higher energy the 90° cross section in the center-of-momentum frame is at least an order of magnitude too small, but does display the correct energy dependence. This energy dependence is related to the properties of the bound-state wave functions and it is plausible that it will persist in an improved treatment (e.g. one which includes exchange currents) which properly accounts for the magnitude of the cross section. Contributions from the 3 He S-states are negligible for photon energies between 100 and 150 MeV, but are dominant outside this energy region.

Meson-exchange currents and the 3He magnetic form factor☆

Abstract The 3 He magnetic form factor for momentum transfer, Q 2 −2 , is calculated using a 3 He wave function obtained from a solution of the Faddeev equations with the Reid soft-core potential. Both the single-nucleon and meson-exchange currents satisfying current conservation are used. Our calculated result for the 3 He magnetic form factor is in reasonably good agreement with the recent experimental data.

Two-pion exchange three-nucleon forces and triton binding energy

Abstract The first-order perturbation correction to the triton binding energy is investigated using two-pion exchange three-nucleon forces constructed the s, d-wave and p-wave πN amplitudes extrapolated to off (pion) mass shell subject to PCAC. We find that the correction is small due to cancellation between the πN s, d-wave and p-wave contributions. The effect of the Fujita-Miyazawa force is also investigated as a special case.

New force or model-dependent effect in the mine gravity measurements?

Abstract The exact solution for the oblate spheroidal layer model of the earth is applied to recent gravity data measured at the Hilton mine, Mount Isa, Queensland. We find that our extracted values of the gravitational constant from the Hilton mine data are consistent with the laboratory value within the accuracy of the mass density profile determination made at the Hilton mine and the surrounding area.

Nuclear chromodynamics and the six-quark compound bag component of the deuteron

Abstract Based upon a new formulation of nuclear chromodynamics, we determine the probability of the six-quark compound bag component of deuteron to be 2.2–5.5% using the experimental np partial width of the dibaryon resonance of Kamae et al.

Two-body photodisintegration of 3H and 3He near the giant resonance: (I). Plane-wave approximation☆

A concise survey of the current status of two-body photodisintegration of the trinucleons in the region of the giant resonance is presented. Calculations neglecting both final-state interactions (FSI) and M1 transitions are presented using the Reid soft-core, Paris and Bonn potentials. D-wave contributions to these reactions are not in agreement in the literature. The present results indicate that approximately (10±4)% of the cross section is due to constructive transitions involving the D-waves. Furthermore, E2 contributions at a photon excitation energy of ∼ 12.5 MeV are found to be approximately 2% for 3He(γ,p)d and 0.1% for 3H(γ,n)d. In addition, fore-aft asymmetry calculations indicate markedly different contributions from E1–E2 interference in a comparison of the 3He and 3H systems.