Speaker
J. Haidenbauer
(Forschungszentrum Jülich)
Description
Recently, a hyperon-nucleon (YN) interaction has been derived
up to next-to-leading order in chiral effective field theory by
the Jülich-Bonn-Munich group. At that order there are contributions
from one- and two-pseudoscalar-meson exchange diagrams and from
four-baryon contact terms without and with two derivatives.
SU(3) flavor symmetry is imposed for constructing the YN interaction
in order to reduce the number of free parameters. In the actual calculation
the SU(3) symmetry is broken, however, by the mass differences between the
Goldstone bosons (pion, eta, K-meson) and between the baryons. For these
masses the known physical values are used.
An excellent description of available Lambda-N and Sigma-N scattering data
has been achieved at next-to-leading order. Corresponding results will be
reported. The in-medium properties of this YN interaction have been investigated.
Specifically, binding energies of the Lambda and Sigma hyperons in nuclear matter
have been calculated, based on conventional first-order Brueckner calculation,
and will be presented and discussed.
Primary author
J. Haidenbauer
(Forschungszentrum Jülich)
Co-authors
A. Nogga
(Forschungszentrum Jülich)
U. G. Meißner
(Universitaet Bonn)