Köln 2004 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 5: Theory I
HK 5.10: Vortrag
Montag, 8. März 2004, 18:15–18:30, D
The nuclear many-body problem in the context of low-energy QCD — •Paolo Finelli1,2, Norbert Kaiser3, Dario Vretenar4, and Wolfram Weise2,3 — 1Physics Department, University of Bologna, Italy — 2ECT*, Villazzano (Trento), Italy — 3Physik Department, Technische Universität München — 4Physics Department, University of Zagreb
A microscopic relativistic point-coupling model of nuclear many-body dynamics constrained by in-medium QCD sum rules and chiral symmetry is derived and applied to nuclear matter and finite nuclei.
The effective Lagrangian is characterized by density-dependent coupling strengths, determined by chiral one- and two-pion exchange and by QCD sum rule constraints for the large isoscalar nucleon self-energies that arise through changes of the quark condensate and the quark density at finite baryon density. This approach is tested in the analysis of the equations of state for symmetric and asymmetric nuclear matter, and of bulk and single-nucleon properties of finite nuclei. In comparison with purely phenomenological mean-field approaches, the built-in QCD constraints and the explicit treatment of pion exchange restrict the freedom in adjusting parameters and functional forms of density dependent couplings.
It is shown that nuclear binding and saturation are almost completely generated by chiral (two-pion exchange) fluctuations, whereas strong scalar and vector fields of about equal magnitude and opposite sign, induced by changes of the QCD vacuum in the presence of baryonic matter, generate the large effective spin-orbit potential in finite nuclei.