Bonn 2010 – wissenschaftliches Programm
HK 24.9: Vortrag
Dienstag, 16. März 2010, 18:45–19:00, HG II
Nuclear energy density functional from chiral pion-nucleon dynamics — •Norbert Kaiser and Wolfram Weise — Physik-Department, Technische Universität München, Garching
We use a recently improved density-matrix expansion (B. Gebremariam, T. Duguet, S.K. Bogner, nucl-th:0910.4979) to calculate the nuclear energy density functional in chiral perturbation theory. Our calculation treats systematically the effects from 1π-exchange, iterated 1π-exchange, and irreducible 2π-exchange with intermediate Δ-isobar excitations, including Pauli-blocking corrections up to three-loop order. We find that the effective nucleon mass M*(ρ) is identical to the one of Fermi-liquid theory. The strength F∇(ρ) of the (∇→ρ)2 surface-term as provided by
the pion-exchange dynamics is in good agreement with that of phenomenological Skyrme forces in the density region ρ0/2 <ρ < ρ0. The spin-orbit coupling strength Fso(ρ) receives contributions from iterated 1π-exchange (of the “wrong sign”) and from three-nucleon interactions mediated by 2π-exchange with virtual Δ-excitation (of the “correct sign”). In the region around ρ0/2 ≃ 0.08 fm−3 where the spin-orbit interaction in nuclei gains most of its weight these two components
tend to cancel, thus leaving all room for the short-range spin-orbit interaction. The strength function FJ(ρ) multiplying the squared spin-orbit density J→ 2 is also studied.
Work supported in part by BMBF, GSI and the DFG cluster of excellence: Origin and Structure of the Universe.