https://doi.org/10.1140/epja/i2016-16019-0
Regular Article - Theoretical Physics
Hyperon-mixed neutron star with universal many-body repulsion
1
Nishina Center for Accelerator-Based Science, Institute for Physical and Chemical Research (RIKEN), 351-0198, Wako, Saitama, Japan
2
National Institute of Technology, Ichinoseki College, 021-8511, Ichinoseki, Iwate, Japan
3
Department of Physics, Chiba Institute of Technology, 2-1-1 Shibazono Narashino, 275-0023, Chiba, Japan
4
IMAPP, University of Nijmegen, Nijmegen, The Netherlands
* e-mail: ys_yamamoto@riken.jp
Received:
28
July
2015
Accepted:
14
October
2015
Published online:
3
February
2016
Neutron stars with large masses require the hard stiffness of equation of state (EoS) of neutron-star matter. On the other hand, hyperon mixing brings about remarkable softening of EoS. In order to solve this problem, a multi-pomeron exchange potential (MPP) is introduced as a model for the universal many-body repulsion in baryonic systems on the basis of the Extended Soft Core (ESC) baryon-baryon interaction. The strength of MPP is determined by analyzing the nucleus-nucleus scattering with the G -matrix folding model. The interactions in
,
and
channels are shown to be consistent with experimental indications. The EoS in neutron-star matter with hyperon mixing is obtained from ESC in addition of MPP, and mass-radius relations of neutron stars are derived. The maximum mass is shown to reach
even in the case of including hyperon mixing on the basis of model-parameters determined by terrestrial experiments.
© SIF, Springer-Verlag Berlin Heidelberg, 2016