质子中子星物质的热力学性质(英文)

Thermal Property of Protoneutron Star Matter

在相对论σ-ω-ρ模型的平均场近似下,研究了质子中子星物质在均熵状态下的组成、温度和物态方程．如给定每一个重子的熵,一些热力学量的值将随重子密度的增加而增加,当考虑超子时,这些值会减小．给定重子密度,中子在S=2时的组分比S=1时的小,而质子、电子、μ子在S=2时的组分比S=1时的大,特别是在低密度区域．S是每个重子的熵．保持重子密度不变,在低密度区域,超子在S=2时的组分比S=1时的大,在高密度区域则相反．同样,在同一重子密度处,S=2时的温度、能量密度及压强分别比S=1时的大．另外,有限熵对粒子组分和温度的影响比对质子中子星物质的物态方程的影响大．还研究了反粒子的贡献,他们确实很小．

We study the composition, the temperature and the equation of state of isoentropic protoneutron star matter in the mean field approximation of the relativistic σ-ω-ρ model. It is shown that, fixing the baryon density, the fraction of neutron at S = 2 is smaller than that at S = 1 and the fractions of proton, electron, and muon at S = 2 are larger than those at S = 1, respectively, especially in the region of low baryon density. Keeping baryon density invariant, the fractions of hyperons at S = 2 are larger（smaller） than those at S ： 1 in the region of relative low（high） density of baryons. Also the temperature, the energy density and the pressure at S=2 are larger than those at S =1, respectively. In addition, we demonstrate that the finite entropy impose more influence on the fractions of particles as well as the temperature than on the equation of state of the protoneutron star matter. As a consequence, the contributions of antiparticles are very small under our consideration.