本文選題：中子星 + 超子�。� 參考：《吉林大學》2016年博士論文

【摘要】：中子星熱演化的研究是當前核天體物理領(lǐng)域的前沿課題。本文主要是在相對論平均場理論與相對論Hartree-Fork框架下,在考慮SU(3)對稱的超子—介子耦合、含有δ介子及矢量介子張量相互作用的情況下,在中子星內(nèi)直接URCA過程方面取得了以下三方面的研究結(jié)果:首先,在相對論平均場框架下利用GM1和TM1模型參數(shù),研究中子星內(nèi)重子直接URCA過程的特點。一方面,我們采用SU(6)和SU(3)對稱下的超子—介子耦合參數(shù)來研究核子和超子直接URCA過程的特點。計算結(jié)果表明由于超子的出現(xiàn)使質(zhì)子和輕子的豐度變小,導致核子直接URCA的中微子發(fā)射率變小。另一方面,我們研究了SU(3)對稱下超子自由度對總中微子發(fā)射率和中微子光度的影響。結(jié)果表明在大部分重子數(shù)密度區(qū)域,SU(3)對稱性下核子直接URCA過程的中微子發(fā)射率大于在SU(6)對稱性下的中微子發(fā)射率,超子直接URCA過程也有類似的趨勢。另外,我們發(fā)現(xiàn)無論是否出現(xiàn)超子,重子直接URCA過程總中微子發(fā)光度都是先增加后減小,這表明同一個發(fā)光度會對應(yīng)兩顆質(zhì)量不同的中子星。其次,在相對論平均場理論框架下,我們研究了超子星內(nèi)同位旋矢量-標量δ介子引入對核子和超子直接URCA過程的影響。結(jié)果表明,δ介子出現(xiàn)使核子和超子有效質(zhì)量發(fā)生劈裂,質(zhì)子和Λ、Σ0、Σ-超子的豐度明顯增加,并且導致核子和超子直接URCA過程中微子發(fā)射率明顯增加,可以預(yù)期δ介子的引入將加快中子星的冷卻速度。最后,在相對論Hartree-Fork近似方法下,研究ω和ρ介子張量相互作用對傳統(tǒng)中子星(npeμ物質(zhì))內(nèi)直接URCA過程的影響,并且結(jié)合Bardeen-Cooper-Schrieffer(BCS)理論研究了ω和ρ介子張量相互作用對核子超流的影響。結(jié)果表明,在核子數(shù)密度大于0.42fm-3的區(qū)域,包含ω和ρ介子張量耦合時的核子直接URCA過程中微子發(fā)射率明顯大于不包含ω和ρ介子張量耦合時的核子直接URCA過程中微子發(fā)射率。此外,ω和ρ介子張量耦合對核子01對能隙的影響也很明顯。結(jié)果表明包含ω和ρ介子張量耦合相互作用導致中子1S0對能隙明顯增加,特別是中子01對能隙的峰值增長了約44%;質(zhì)子01對能隙在ρ=0.0~0.079fm-3核子數(shù)密度區(qū)域減小,在ρ=0.079~0.383fm-3密度區(qū)域增加。這些變化必然會影響中子星的冷卻性質(zhì)。我們的結(jié)果為研究ω和ρ介子張量耦合相互作用對中子星冷卻性質(zhì)的影響提供了基礎(chǔ)。
[Abstract]:The thermal evolution of neutron stars is a frontier subject in the field of nuclear astrophysics.In this paper, under the framework of relativistic mean field theory and relativistic Hartree-Fork, the symmetric hyperon-meson coupling with 未 meson and vector meson Zhang Liang is considered.The research results of direct URCA processes in neutron stars are as follows: firstly, the characteristics of direct URCA processes in neutron stars are studied by using the parameters of GM1 and TM1 models under the framework of relativistic mean field.On the one hand, we study the characteristics of direct URCA processes of nucleons and hyperons by using the hyperon-meson coupling parameters under the symmetry of Su ~ (6) and Su ~ (3).The results show that the abundance of protons and leptons is reduced due to the appearance of hyperons, which leads to the reduction of neutrino emissivity of nucleon direct URCA.On the other hand, we study the effect of hyperon degree of freedom on the total neutrino emissivity and neutrino luminosity under SUP3) symmetry.The results show that the neutrino emissivity of the nucleon direct URCA process is higher than that of the nucleon direct URCA process under most baryon density regions. The direct URCA process has a similar trend.In addition, we find that the total neutrino luminosity of baryon direct URCA process increases first and then decreases, which indicates that the same luminosity will correspond to two neutron stars with different mass.Secondly, in the framework of relativistic mean field theory, we study the influence of the introduction of isospin vector-scalar mesons on the direct URCA processes of nucleons and hyperons.The results show that the appearance of 未 mesons cleavage the effective mass of nucleon and hyperon, increase the abundance of proton and 鈭，

本文編號：1744541