PROPERTIES OF NUCLEAR-MATTER IN CUTOFF FIELD-THEORY AND THE LOW-ENERGY EFFECTIVE LAGRANGIAN IN THE HARTREE APPROXIMATION

The properties of nuclear matter are studied in the cutoff field theor y. It is indicated that the properties of nuclear matter are somewhat different from those described by the ordinary renormalization procedu res when the cutoff is small (<5 GeV). It is also found that, under th e Hartree approximation, the small cutoff makes the equations of state hard, in particular at higher densities. The theory is modified in th e framework of renormalization group methods with arbitrary cutoff Lam bda'. It is found that the expansion in terms of the sigma-meson field phi is more favorable than the naive expansion of the inverse of Lamb da' when we do not use a very large Lambda'. II also indicated that th e phi(5) and phi(6)-terms seem to be needed in the effective Lagrangia n of the cutoff field theory in the Hartree approximation.