超子耦合参数对热前中子星物质的影响

Effect of Hyperon Couplings on Thermal Protoneutron Star Matter

在相对论平均场理论框架内,利用Λ超子的结合能和中子星质量的观测数据得到超子标量介子耦合参数χσ的范围是0.33—0.77。在这个范围内,研究了χσ取不同值时,包含核子,Λ和Ξ超子的热前中子星(固定单个重子熵s=1)的性质。结果表明,如果超子耦合参数变大,前中子星核心温度变高,中微子丰度变低,前中子星的亚稳态质量范围变小。如果χσ超过了0.75,前中子星不可能演变成黑洞。联系SN1987A讨论了这一结果的意义。

In the framework of the relativistic mean field theory（RMFT）,protoneutron stars with hyperons are studied.To be compatible with neutron star masses,the hyperon scalar coupling χσ should lie in the range of 0.33—0.77.As the hyperon scalar coupling increases,in protoneutron star matter,the core temperature increases whereas the abundance of neutrinos decreases.The metastable mass range of protoneutron stars narrows as the temperature increases.It is found that a protoneutron star cannot subside into a low mass black hole when χσ0.75.Furthermore,the case of SN1987A is discussed.