Chiral SU(3) dynamics and $\Lambda$-hyperons in the nuclear medium

Abstract

We present a novel approach to the density dependent mean field and the spin-orbit interaction of a $\Lambda$-hyperon in a nuclear many-body system, based on flavor-SU(3) in-medium chiral perturbation theory. The leading long-range $\Lambda N$-interaction arises from kaon exchange and from two-pion exchange with a $\Sigma$-hyperon in the intermediate state. The empirical $\Lambda$-nucleus potential depth of about $-28$MeV is well reproduced with a single cutoff scale, $\bar{\Lambda }=0.7$GeV, effectively representing all short-distance (high-momentum) dynamics not resolved at scales characteristic of the nuclear Fermi momentum. This value of $\bar{\Lambda }$ is remarkably consistent with the one required to reproduce the empirical saturation point of isospin-symmetric nuclear matter in the same framework. The smallness of the $\Lambda$-nuclear spin-orbit interaction finds a natural (yet novel) explanation in terms of an almost complete cancellation between short-range contributions (properly rescaled from the known nucleonic spin-orbit coupling strength) and long-range terms generated by iterated one-pion exchange with intermediate $\Sigma$-hyperons. The small $\Sigma \Lambda$-mass difference figures prominently in this context.

9 pages, 4figures

References in corpus (5)

• Relativistic nuclear model with point-couplings constrained by QCD and chiral symmetry
• Nuclear energy density functional from chiral pion-nucleon dynamics
• Goldberger-Treiman constraint criteria for hyperon coupling constants
• Three-body spin-orbit forces from chiral two-pion exchange
• Nuclear spin-orbit interaction from chiral pion-nucleon dynamics

Cited by in corpus (20)

• Modern Theory of Nuclear Forces
• Hyperon Puzzle: Hints from Quantum Monte Carlo Calculations
• Hyperon-nucleon interaction at next-to-leading order in chiral effective field theory
• Hyperons in nuclear matter from SU(3) chiral effective field theory
• Dense baryonic matter: constraints from recent neutron star observations
• Hyperon-nuclear interactions from SU(3) chiral effective field theory
• $\bar{\mathrm{D}}$ and $\mathrm{B}$ mesons in nuclear medium
• Generalized mass formula for non-strange and hyper nuclei with SU(6) symmetry breaking
• A study of hyperons in nuclear matter based on chiral effective field theory
• Probing gluon dynamics by charm and bottom mesons in nuclear medium from heavy meson effective theory with 1/M-corrections
• Hypernuclear single particle spectra based on in-medium chiral SU(3) dynamics
• Novel model for particle emission in small collision systems
• Note on spin-orbit interactions in nuclei and hypernuclei
• Chiral dynamics of $\Sigma$-hyperons in the nuclear medium
• In-medium chiral SU(3) dynamics and hypernuclear structure
• Hyperon-nucleon single-particle potentials with low-momentum interactions
• Contribution of the rho meson and quark sub-structure to the nuclear spin-orbit potential
• $\Sigma$-nuclear spin-orbit coupling from two-pion exchange
• The baryon-decuplet in the chiral dynamics of Lambda-hyperons in nuclear matter
• Hypernuclei and in-medium chiral dynamics