Saturation of nuclear matter and roles of many-body forces: nuclear matter in neutron stars probed by nucleus—nucleus scattering

Abstract

Yoichiro Nambu put a great foot print in nuclear physics in the era of its fundamental developments including his pioneering insight into essential ingredients of repulsive core of nuclear force and its relation to the saturation of nuclear matter. The present review article focuses onto recent developments of the interaction models between colliding nuclei in terms of Brueckner's G-matrix theory starting from realistic nuclear forces and the saturation property of symmetric nuclear matter as well as neutron-star matter. A recently proposed unique scenario of extracting the saturation property of nuclear matter and stiffness of neutron stars through the analysis of nucleus-nucleus elastic scattering in laboratories is presented in some detail.

Tribaryon Configurations and Three Nucleon Repulsions at Short Distance

“…Since we only consider the totally symmetric spatial wave function, the rest part of the wave function should be antisymmetric in SU(3) flavor symmetric case. Additionally, since the color state of the tribaryon is singlet which is [3,3,3] in Young tableau, the flavor-spin state should be its conjugate state which is also [3,3,3]. Then, we can classify the possible flavor and spin state of the tribaryon as follows.…”

“…The newly observed neutron stars [1,2], which has around twice of solar mass, has rekindled the interest in the hyperon puzzle in neutron stars. A natural way to solve this puzzle is to introduce the repulsive short distance three-body nuclear force including hyperons because three-body force becomes more important at high density and its repulsive interaction naturally leads to a stiffer equation of state [3,4]. Although there have been several researches about three-body force using chiral effective field theory [5][6][7], only few studies have investigated the three-nucleon interaction in terms of nine quarks system [8,9].…”

Tribaryon configurations and the inevitable three nucleon repulsions at short distance

“…Phenomenologically, the long distance part of the three nuclear force is obtained using the pion mediated interactions [6,7] which gives the additional attraction necessary to fit the experimental 3 H binding energy. However, as one tries to go beyond the few body system and understand the saturation properties of nuclear matter [6,8] and the compressibility consistent with experiments [9], it becomes clear that the three body nuclear force including those involving hyperons [10] are repulsive at short distance.…”

The effective relativistic quantum field theory for nuclear matter with many‐body forces revisited

“…Encouraged by this formulation, and inspired by recent experimental results (Sakuragi ), in this work, we extend this model by adding to the original theoretical description of many‐body forces involving self‐interaction and meson cross‐interaction terms in the vector–isoscalar and vector–isovector meson sectors.…”

“…The influence of the combination of the relativistic mean field theory and the presence of nonlinear meson self‐interaction and meson cross‐interaction terms to study the properties of neutron star matter in equilibrium with and without hyperon fields has been studied quite frequently in the literature (Sakuragi ; Shao & Liu ). However, in these studies, the lack of a more systematic and consistent conceptual basis for the insertion of different combinations of cross‐terms involving meson fields emerges.…”