Nuclear structure is governed by the fundamental laws of electromagnetism

Contradicting interpretations of the nuclear force as given by two contrasted approaches like the meson theory and the quantum chromodynamics, are overcome here by reviving the basic electromagnetic laws which are applicable on the existing charged subconstituents in nucléons. On this basis, considerable charge distributions in nucleons are determined after a careful analysis of the magnetic moments and the results of the deep inelastic scattering. Basic equations derived from the distributed charges of oriented spins of nucléons give strong and short ranged forces leading exactly to the binding energies of the deuteron and other nuclei. According to these interactions, p-p and n-n systems repel and only the p-n bonds form rectangles and closely packed parallelepipeds. Such contrary forces create structures of saturation and of finite number of nucléons. They also invalidate the charge independence hypothesis and differ fundamentally from the central potential and the effects of the Pauli principle of the electronic configurations responsible for the development of the models of the Fermi gas and nuclear shell. There are two kinds of p-n bonds, which imply anisotropy, leading often to elongated shapes of vibrational and rotational modes of excitation, while the surface tension contributes to the creation of non elongated shapes of stable arrangements. Finally, for A>40 a type of shell structure provides new rules for understanding the structure of magic nuclei for N>Z and the increasing ratio N/Z with A.

The Role of the Isospin 3/2 Component in Elastic Neutron-Deuteron Scattering and in the Deuteron Breakup Reaction

We discuss the importance of the three-nucleon isospin [Formula: see text] component in elastic neutron-deuteron scattering and in the deuteron breakup reaction. The contribution of this amplitude originates from charge-independence breaking of the nucleon-nucleon potential. We study the magnitude of that contribution to the elastic scattering and breakup observables, taking the Av18 nucleon-nucleon potential alone or combined with the Urbana IX three-nucleon force as well as the locally regularized chiral N4LO nucleon-nucleon potential alone or supplemented by the chiral N2LO three-nucleon force. We find that the isospin [Formula: see text] component is important for the breakup reaction and the proper treatment of charge-independence breaking in this case requires the inclusion of the [Formula: see text] state with isospin [Formula: see text]. For neutron-deuteron elastic scattering the [Formula: see text] contributions are insignificant and charge-independence breaking can be accounted for by neglecting [Formula: see text] component and using the effective t-matrix generated with the so-called [Formula: see text] rule.

QUEST FOR MAGICITY IN EXOTIC NUCLEI

Low-lying excitation properties of exotic nuclei in the vicinity of the canonical magic number 8 have been investigated through the level lifetime measurement on the neutron-rich isotope 13 B with N = 8 and the missing-mass spectroscopy on the proton unbound nucleus 12 O with Z = 8. The observed trends of the transition probabilities and level schemes have been discussed in comparison with the advanced shell model calculations, which points to the universality as well as the charge independence of the shell quenching phenomena far from stability.

CHARGE INDEPENDENCE BREAKING IN MESON PRODUCTION?

We investigate by global and local fits whether existing data on pp → π+d and np → π0d have indications on charge dependent forces other than the Coulomb force and the effect of differing thresholds. We find evidence in the energy (or pion momentum) dependence of the total cross sections close to threshold.