NUCLEON IN NUCLEAR-MATTER

We use the toy model of baryon bag formation to study the changes in the structure of a nucleon when it is placed in nuclear matter. Several interesting qualitative results have been found. We find that M*, the nucleon mass in nuclear matter, does not scale with F(pi)*, the latter being the value of the sigma field in nuclear matter. The product M*<r2>1/2* is nearly independent of nuclear density. The coupling constant g(sigma-NN)* decreases with density. The coupling constant g(pi-NN)*/2M* and the rho-nucleon tensor coupling constant, f(rho-NN)*/2M*, increase with density at the same rate. The coupling constants g(omega-NN)* and g(rho)* also increase at the same rate, but the rate itself is low. We find that M* + g(sigma-NN)*(F(pi) - F(pi))* is approximately independent of the nuclear density. The magnetic moments increase, while g(A)*(0) decreases. At half the normal density these changes are in the range 3-7 % depending on the parameters used. We discuss briefly the implications of these results on the properties of nuclear matter.