https://doi.org/10.1140/epja/s10050-020-00180-2
Regular Article – Theoretical Physics
Hyperon–nucleon three-body forces and strangeness in neutron stars
Physics Department, Technical University of Munich, 85748, Garching, Germany
* e-mail: nkaiser@ph.tum.de
Received:
28
January
2020
Accepted:
11
June
2020
Published online:
1
July
2020
Three-body forces acting on a 
hyperon in a nuclear medium are investigated, with special focus on the so-called hyperon puzzle in neutron stars. The hyperon–nucleon two-body interaction deduced from SU(3) chiral effective field theory is employed at next-to-leading order. Hyperon–nucleon three-body forces are approximated using saturation by decuplet baryons and are transcribed to density-dependent effective two-body interactions. These together are taken as input in a Brueckner–Bethe–Goldstone equation with explicit treatment of the 
and 
coupled channels. Single-particle potentials of a hyperon in symmetric nuclear matter and neutron matter are calculated. With parameters of the 
three-body force constrained by hypernuclear phenomenology, extrapolations to high baryon density are performed. By comparison of the and neutron chemical potentials at densities characteristic of the core of neutron stars it is found that the combined repulsive effects of two- and three-body correlations can make the appearance of hyperons in neutron stars energetically unfavourable, thus potentially offering a possible answer to a longstanding query.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
