密度依赖口袋常数下奇异夸克物质及奇异星

Strange Quark Matter and Strange Stars in the Effective Mass Bag Model with Density Dependent Bag Parameter

在有效质量口袋模型(EMBM)下采用密度依赖口袋常数描述奇异夸克物质,研究了口袋常数的密度依赖性对奇异夸克物质的状态方程及奇异星性质的影响.结果表明,密度依赖口袋常数在低密度处较大,随着密度增大而明显变小,很好地体现了低密度处色禁闭、高密度处夸克退紧闭的量子色动力学(QCD)基本精神.与常数口袋常数的情形相比,密度依赖口袋常数下奇异夸克物质的状态方程变硬,奇异星的引力质量和对应的半径均有明显变大,且均在脉冲星的观测值范围内,表明该模型适合于描述质量和半径较大的奇异星内的夸克物质.

Strange quark matter equations of state and properties of strange stars are studied,using the effective mass bag model with density-dependent bag parameters.Numerical results indicate that the density-dependent bag constants are very large at low baryon number density and decrease distinctly with increasing baryon number density,agreeing with the QCD spirit,i.e.color confinement at low density and quark deconfinement at large baryon number density.Strange quark matter equations of state stiffen and gravitational mass and the corresponding radii of strange stars increase in density-dependent bag parameter compared with the constant bag parameter case,and they still remain in the scope of observational value for pulsars,indicating that this model is suitable for describing quark matter interior of strange stars with big mass and radius.