Hypernuclei and in-medium chiral dynamics

Abstract

A recently introduced relativistic nuclear energy density functional, constrained by features of low-energy QCD, is extended to describe the structure of hypernuclei. The density-dependent mean field and the spin-orbit potential of a $\Lambda$-hyperon in a nucleus, are consistently calculated using the SU(3) extension of in-medium chiral perturbation theory. The leading long-range $\Lambda N$ interaction arises from kaon-exchange and $2\pi$-exchange with a $\Sigma$-hyperon in the intermediate state. Scalar and vector mean fields, originating from in-medium changes of the quark condensates, produce a sizeable {\em short-range} spin-orbit interaction. The model, when applied to oxygen as a test case, provides a natural explanation for the smallness of the effective $\Lambda$ spin-orbit potential: an almost complete cancellation between the background contributions (scalar and vector) and the long-range terms generated by two-pion exchange.

8 pages and 6 figures. To appear in the proceedings of the Theoretical nuclear physics school "Exotic Nuclei: New Challenges", Les Houches (France) May 7-18, 2007

References in corpus (16)

• Recent Progress in Quantum Hadrodynamics
• Density Dependent Hadron Field Theory
• QCD Sum Rules and Applications to Nuclear Physics
• Chiral Dynamics and Nuclear Matter
• The Nuclear Spin-Orbit Force in Chiral Effective Field Theories
• Chiral approach to nuclear matter: Role of two-pion exchange with virtual delta-isobar excitation
• Relativistic nuclear model with point-couplings constrained by QCD and chiral symmetry
• Relativistic nuclear energy density functional constrained by low-energy QCD
• Nuclear energy density functional from chiral pion-nucleon dynamics
• Large Lorentz Scalar and Vector Potentials in Nuclei
• Next Generation Relativistic Models
• Chiral SU(3) dynamics and $\Lambda$-hyperons in the nuclear medium
• The relativistic self-energy in nuclear dynamics
• Three-body spin-orbit forces from chiral two-pion exchange
• In-medium chiral SU(3) dynamics and hypernuclear structure
• Spin-orbit coupling in nuclei and realistic nucleon-nucleon potentials

Cited by in corpus (1)

• Hypernuclear single particle spectra based on in-medium chiral SU(3) dynamics