arXiv subjects
Publications and source records attributed to B. E. Grinyuk.
A theoretical possibility is shown for the bound state of a tetraneutron to exist in the case of the proposed neutron-neutron potentials in the singlet state with two attractive wells separated by a repulsive barrier. The anomalous behaviours are revealed for the calculated size, density distribution, and pair correlation functions of a hypothetical tetraneutron.
A precise study within variational approach of the basic properties of the three-particle spectrum and structure functions with Gaussian potential near the critical coupling constant of interaction where the Efimov effect takes place is carried out. A method is developed to calculate highly excited states with very small binding energies, and numerical analysis is carried out for the ground and three excited energy states. For these states, one-particle density distributions, formfactors, pair correlation functions, and momentum distributions are calculated. It is found that the second excited state has already all the basic features of a level from the infinite Efimov series. An essential asymmetry is found in the position of energy levels with respect to the critical constant point. A halo-type structure is revealed in the one-particle density distributions, and formfactors are shown to have specific dips of finite depth, the number of dips being equal to the number of the state. The behaviour of pair correlation functions and momentum distributions is studied for three-particle states.
A representation without explicit use of the isospin formalism is developed for the precise study of few-nucleon systems, and the advantages of the proposed approach are demonstrated. Using the example of three-nucleon systems with central exchange NN-interaction potentials of the general type, the complete equivalence is shown for the both approaches with and without the isospin formalism. The new systems of equations contain a less number of components as compared to the commonly used ones and are more suitable for precise study of few-nucleon systems, in particular, within variational approaches. Optimal variational schemes are developed with Gaussian basis, and the binding energies, r.m.s. radii, density distributions, formfactors, and pair correlation functions are calculated with a high and controlled precision for 3H and 3He nuclei.