Quasiparticle interaction in nuclear matter with chiral three-nucleon forces

We derive the effective interaction between two quasiparticles in symmetric nuclear matter resulting from the leading-order chiral three-nucleon force. We restrict our study to the L=0,1 Landau parameters of the central quasiparticle interaction computed to first order. We find that the three-nucleon force provides substantial repulsion in the isotropic spin- and isospin-independent component F0 of the interaction. This repulsion acts to stabilize nuclear matter against isoscalar density oscillations, a feature which is absent in calculations employing low-momentum two-nucleon interactions only. We find a rather large uncertainty for the nuclear compression modulus K due to a sensitive dependence on the low-energy constant c3. The effective nucleon mass M⁎ on the Fermi surface, as well as the nuclear symmetry energy β, receive only small corrections from the leading-order chiral three-body force. Both the anomalous orbital g-factor δgl and the Landau–Migdal parameter (characterizing the spin–isospin response of nuclear matter) decrease with the addition of three-nucleon correlations. In fact, δgl remains significantly smaller than its value extracted from experimental data, whereas still compares well with empirical values. The inclusion of the three-nucleon force results in relatively small p-wave (L=1) components of the central quasiparticle interaction, thus suggesting an effective interaction of short range.