Nuclear mean field from chiral pion–nucleon dynamics Original Research Article

Using the two-loop approximation of chiral perturbation theory, we calculate the momentum- and density-dependent single-particle potential of nucleons in isospin-symmetric nuclear matter. The contributions from one- and two-pion exchange diagrams give rise to a potential depth for a nucleon at rest of U(0,kf0)=−53.2 MeV at saturation density. The momentum dependence of the real part of the single-particle potential U(p,kf0) is nonmonotonic and can be translated into a mean effective nucleon mass of View the MathML source. The imaginary part of the single-particle potential W(p,kf) is generated to that order entirely by iterated one-pion exchange. The resulting half width of a nucleon hole-state at the bottom of the Fermi sea comes out as W(0,kf0)=29.7 MeV. The basic theorems of Hugenholtz–Van-Hove and Luttinger are satisfied in our perturbative two-loop calculation of the nuclear mean field.