We employ a comprehensive set of relativistic mean-field(RMF)models to investigate the role of hyperons(Λ,∑^(±,0),andΞ^(-),0)in dense nuclear matter.We consider various RMF models that span a wide range of hig...We employ a comprehensive set of relativistic mean-field(RMF)models to investigate the role of hyperons(Λ,∑^(±,0),andΞ^(-),0)in dense nuclear matter.We consider various RMF models that span a wide range of highdensity behaviors of equations of state(EoSs),symmetry energy coefficients,and hyperon-meson coupling schemes.Our aim is to assess how the inclusion of hyperons in nucleonic matter influences the key neutron star properties,including the maximum mass(M_(max)),stellar radius(R_(max)),and tidal deformability(Λ_(max)).By varying the vector meson-hyperon coupling strength(X_(ωY))over a wide range and considering the SU(6)symmetry,we find that a decrease in X_(ωY)results in an increased hyperon population.This leads to a significant softening of the EoS and a reduction in the maximum mass of a neutron star.The models with strong vector repulsion(larger value of X_(ωY))show a dominance ofΛandΞ^(-)hyperons,withΞ^(0)appearing only at higher densities.The neutron star properties,such as M_(max),R_(max),andΛ_(max),are strongly affected by the hyperonization for all RMF models.It is observed that the canonical star properties like R_(1.4)andΛ_(1.4)remain largely unaffected by the presence of hyperons in nucleonic EoSs under fixed vector coupling strengths,except when couplings are based on SU(6)symmetry.This behavior can be attributed to the fact that,although hyperons appear in the very centre of a 1.4 M_(⊙)star,their population fraction is extremely small and therefore has a negligible effect on global stellar properties like R_(1.4)andΛ_(1.4).Furthermore,to support a star with observational constraint of M_(max)≥2M_(⊙),the vector coupling strength X_(ωY)must lie in the range 0.8−0.9.Our results highlight the critical role of vector coupling strength in governing hyperonization and its impact on neutron star observables.It is found that increasing X_(ωY)improves compliance with the 2M_(⊙)mass constraint by suppressing early hyperonization.The critical role of the slope of symmetry energy(L)in regulating the impact of hyperonization on neutron star observables is also studied.展开更多
文摘We employ a comprehensive set of relativistic mean-field(RMF)models to investigate the role of hyperons(Λ,∑^(±,0),andΞ^(-),0)in dense nuclear matter.We consider various RMF models that span a wide range of highdensity behaviors of equations of state(EoSs),symmetry energy coefficients,and hyperon-meson coupling schemes.Our aim is to assess how the inclusion of hyperons in nucleonic matter influences the key neutron star properties,including the maximum mass(M_(max)),stellar radius(R_(max)),and tidal deformability(Λ_(max)).By varying the vector meson-hyperon coupling strength(X_(ωY))over a wide range and considering the SU(6)symmetry,we find that a decrease in X_(ωY)results in an increased hyperon population.This leads to a significant softening of the EoS and a reduction in the maximum mass of a neutron star.The models with strong vector repulsion(larger value of X_(ωY))show a dominance ofΛandΞ^(-)hyperons,withΞ^(0)appearing only at higher densities.The neutron star properties,such as M_(max),R_(max),andΛ_(max),are strongly affected by the hyperonization for all RMF models.It is observed that the canonical star properties like R_(1.4)andΛ_(1.4)remain largely unaffected by the presence of hyperons in nucleonic EoSs under fixed vector coupling strengths,except when couplings are based on SU(6)symmetry.This behavior can be attributed to the fact that,although hyperons appear in the very centre of a 1.4 M_(⊙)star,their population fraction is extremely small and therefore has a negligible effect on global stellar properties like R_(1.4)andΛ_(1.4).Furthermore,to support a star with observational constraint of M_(max)≥2M_(⊙),the vector coupling strength X_(ωY)must lie in the range 0.8−0.9.Our results highlight the critical role of vector coupling strength in governing hyperonization and its impact on neutron star observables.It is found that increasing X_(ωY)improves compliance with the 2M_(⊙)mass constraint by suppressing early hyperonization.The critical role of the slope of symmetry energy(L)in regulating the impact of hyperonization on neutron star observables is also studied.
