论文标题
在修改的NJL模型中对非强制夸克恒星的研究
The study of nonstrange quark stars within a modified NJL model
论文作者
论文摘要
在这项工作中，采用了适当的时间正则化的修改后的Nambu-Jona-Lasinio（NJL）模型来研究非强制夸克恒星的结构。传统NJL模型中四屈服交互的耦合常数被修改为$ g = g_1+g_2 \ langle \barψψ\ rangle $，以突出夸克传播器对Gluon opagator的反馈。为了研究状态方程（EO）对这种修饰以及真空压力的依赖性，我们选择了九个代表性的EOSS进行比较。发现较小的$ g_1 $导致EOS更硬，更高的真空压力（即较小的袋子常数）在低能密度下产生较软的EOS。进一步表明，在此修改后的NJL模型下，最重的夸克恒星不仅满足了PSR J0740+6620的近期质量测量，而且还满足X射线正时观测值的半径约束。相应的潮汐变形性也与GW170817的观测值一致。
In this work, a modified Nambu-Jona-Lasinio (NJL) model with proper-time regularization is employed to study the structure of nonstrange quark stars. The coupling constant of four-fermion interaction in the conventional NJL model is modified as $G=G_1+G_2\langle\barψψ\rangle$ to highlight the feedback of quark propagator to gluon propagator. To study the dependence of the equation of state (EOS) on this modification as well as the vacuum pressure, we choose nine representative EOSs for comparison. It is found that a smaller $G_1$ leads to a stiffer EOS, and a higher vacuum pressure (i.e., a smaller bag constant) yields a softer EOS at low energy density. It is further shown that the heaviest quark star under this modified NJL model satisfies not only the recent mass measurement of PSR J0740+6620, but also the radius constraints from X-ray timing observations. The corresponding tidal deformability is also in agreement with the observations of GW170817.
