Three-body couplings in RMF and its effects on hyperonic star equation of state

Abstract

We develop a new relativistic mean field (RMF) model including explicit three-body couplings and apply it to hyperonic systems and neutron star matter. The recent observation of the massive mass neutron star has given us a puzzle; when strange hadrons including hyperons are taken into account, the equation of state (EOS) becomes too soft to support the observed two-solar-mass neutron star. Three-baryon repulsion is a promising ingredient to answer this puzzle. We demonstrate that it is possible to consistently explain the massive neutron star and hypernuclear data when we include three-body couplings and modify the hyperon vector couplings from the flavor SU(3) values.