MESON-MODE MIXING IN THE CALCULATION OF THE NUCLEON-NUCLEON INTERACTION

We consider pion exchange between nucleons in the one-boson-exchange m odel and in a model based upon the use of the quark-quark T matrices o f the Nambu-Jona-Lasinio (NJL) model. We study the relation between th e meson-nucleon form factors of the boson-exchange model and the form factors that appear in our application of the NJL model. Previously we indicated that the form factors of the boson-exchange model are not p hysical quantities. For example, we saw that, while the vertex form fa ctor of the boson-exchange model depends upon a parameter Lambda(pi)=1 .3 GeV in the case of pion exchange, the corresponding physical parame ter characterizing the meson-nucleon vertex is Lambda(pi)similar or eq ual to 0.8 GeV. In this paper we study how the mixing of the pion and the axial-vector (T=1) mode affects the value of lambda(pi) needed in our model. We find that the two models of pion exchange in the nucleon -nucleon interaction can be put into excellent agreement if lambda(pi) =0.9 GeV is used.