Chiral pion–nucleon dynamics in finite nuclei: Spin–isospin excitations

The nuclear density functional framework, based on chiral dynamics and the symmetry breaking pattern of low-energy QCD, is extended to the description of collective nuclear excitations. Starting from the relativistic point-coupling Lagrangian introduced in [P. Finelli, N. Kaiser, D. Vretenar, W. Weise, Nucl. Phys. A 770 (2006) 1], the proton–neutron (quasiparticle) random phase approximation is formulated and applied to investigate the role of chiral pion–nucleon dynamics in excitation modes involving spin and isospin degrees of freedom, e.g. isobaric analog states and Gamow–Teller resonances.