Resonance Model ofNNInteractions and Its Application to Nucleus

Abstract

It is supposed that the account of me interaction allows to describe the contribution of higher order approximations of the pion theory to NN-potentials by a phenomenological introduction of the one-particle exchange of 1m resonances with definite symmetries. Various types of resonance symmetries which may give the contribution to the nuclear forces are discussed. An important role of the ro-resonance is emphasized. An example of the resonance model is considered in which the exchange of two (/=0 and I=l) vector and one (I=O) scalar resonances occurs. The estimates of the coupling constants of these resonances with the nucleon are made from a comparison with the phenomenological NN-potential of Hama­ da, Johnston (H-1). Good qualitative and ·satisfactory quantitative agreement with H-J po­ tentials has been obtained. It is shown that, if applied to the nucleus, the resonance model permits to give.a microscopic interpretation of the semiempirical formula for the nuclear masses. A comparison with the coefficients of the formula leads to additional restrictions on the parameters of the model. two, three, etc., meson exchange, i.e. about the essential contribution of the higher order approximations of the perturbation theory. The development of the dispersion methods which are free from the diffi­ culties encountered in the perturbation theory and the recently discovered strong nn interaction which is demonstrated, first of all, in the so-called pion resonances*) make a new approach to the nature of NN-potentials possible. It may be sup­ posed that due to nn interaction there occurs the exchange of groups of cor­ related pions, resonances (R) between nucleons, unlike the perturbation theory where the exchange of a number of individual pions takes place. The large nN coupling constant which in the perturbation theory indicates an essential contribution of the higher order approximations implies in our approach the existence of still large effective coupling constants gIlN of the resonances with *) On the mt resonances see the Proceedings of the XI Rochester Conference,S) and from