Single-particle potential in a chiral approach to nuclear matter including short range NN-terms

Abstract

We extend a recent chiral approach to nuclear matter of Lutz et al. [Phys. Lett. B474 (2000) 7] by calculating the underlying (complex-valued) single-particle potential U(p,k_f) + i W(p,k_f). The potential for a nucleon at the bottom of the Fermi-sea, U(0,k_{f0})= - 20.0 MeV, comes out as much too weakly attractive in this approach. Even more seriously, the total single-particle energy does not rise monotonically with the nucleon momentum p, implying a negative effective nucleon mass at the Fermi-surface. Also, the imaginary single-particle potential, W(0,k_{f0}) = 51.1 MeV, is too large. More realistic single-particle properties together with a good nuclear matter equation of state can be obtained if the short range contributions of non-pionic origin are treated in mean-field approximation (i.e. if they are not further iterated with 1pi-exchange). We also consider the equation of state of pure neutron matter $bar{E}_n(k_n)$ and the asymmetry energy A(k_f) in that approach. The downward bending of these quantities above nuclear matter saturation density seems to be a generic feature of perturbative chiral pion-nucleon dynamics.

12 pages, 7 figures, submitted to Physical Review C

Cited by in corpus (8)

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• Relativistic nuclear energy density functional constrained by low-energy QCD
• Nuclear energy density functional from chiral pion-nucleon dynamics
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• Spin-asymmetry energy of nuclear matter
• Quasi-particle interaction in nuclear matter from chiral pion-nucleon dynamics
• Chiral approach to nuclear matter: Role of explicit short-range NN-terms
• Spin-isospin stability of nuclear matter