重离子碰撞中阈能附近超子产生机制

在量子分子动力学输运模型LQMD(Lanzhou quantum molecular dynamics transport model)框架下,研究了不同重离子反应系统中同位旋和核介质效应对超子产生以及动能谱的影响.基于手征有效场理论,引入了动量和密度相关的排斥超子-核子光学势,并且考虑了该势对超子产生截面阈能的修正....

Hyperon Dynamics and Production in Heavy-ion Collisions Near Threshold Energy

Within the framework of Lanzhou quantum molecular dynamics(LQMD) transport model, the isospin and in-medium effects on the hyperon production and kinetic energy spectra in the reaction of different heavy-ion reaction are investigated thoroughly. A repulsive hyperon-nucleon potential which is related to the hyperon momentum and baryon density from the chiral effective field theory is implemented into the model. The correction on threshold energy of the elementary hyperon cross section is taken into account. It is found that the $ \varSigma $yields are suppressed in the domain of midrapidity and domain of kinetic energy spectra with the potential. The emission behavior of the hyperons is also affected by the repulsive hyperon-nucleon potential. The hyperons tend to move along the direction of the beam and along the direction perpendicular to the reaction plane. Finally, we found that $\varSigma^{-}$/$\varSigma^{+}$ yield ratio depends on the stiffness of nuclear symmetry energy in the high-energy region. The $\varSigma^{-}$/$\varSigma^{+}$ yield ratio with a hard symmetry energy is increased by the repulsive hyperon-nucleon potential. And it is found that the compressibility of nuclear matter will affect the hyperon production obviously.