The pionic effect on the binding energy of relativistic particle hole excitation in nuclear matter

The renormalization of pion-exchange nucleon self-energy in nuclear matter is done by dispersion relation. The exchange and correlation energies (in the ring approximation) of pion, σ and ω mesons are derived and used to calculate the binding energy of nuclear matter at zero temperature. The authors find that the pionic contribution to the binding energy fails to lift the high density end of the binding energy curve, that is, the binding energy can not saturate without a density dependent correction to the σNN and ωNN coupling constants. But the binding energy can saturate in the relativistic Hartree approximation plus the exchange and correlation energies of π meson