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arXiv 1803.03338nucl-thnucl-ex
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用核子流探讨对称能的密度依赖性

Probing the density dependence of the symmetry energy by nucleon flow

Xiao-Hua Fan, Gao-Chan Yong, Wei Zuo

摘要:

在与同位旋相关的Boltzmann-Uehling-Uhlenbeck输运模型框架下,研究了核子可观测量对核对称能的敏感区域。发现在0.3 GeV/核子的$^{132}$ Sn+ $^{124}$ Sn反应中,对对称能敏感的可观测n/p比实际上只是探测了低于$1.5ρ_0$密度的密度依赖对称能,而有效地探测了饱和密度附近或略低于饱和密度的密度依赖对称能.在半中心$^{132}$ Sn+ $^{124}$ Sn反应中,当入射能量从0.3 GeV/核子到0.6 GeV/核子变化时,核子椭圆流可以探测到对称能从低密度区到高密度区的变化.在0.6 GeV/核子的半中心$^{197}$ Au+ $^{197}$ Au反应中,核子横向流和椭圆流对核对称能的高密度行为更为敏感.因此,在重反应体系中,入射束能量较高的核子观测量更适合于探测对称能的高密度行为。本文的研究有助于从中能重离子碰撞中观察到的核子流中获得有关密度相关对称能的更具体的信息。

英文摘要:

In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, sensitive regions of some nucleon observables to the nuclear symmetry energy are studied. It is found that the symmetry energy sensitive observable n/p ratio in the $^{132}$Sn+$^{124}$Sn reaction at 0.3 GeV/nucleon in fact just probes the density-dependent symmetry energy below the density of $1.5ρ_0$ and effectively probes the density-dependent symmetry energy around or somewhat below the saturation density. Nucleon elliptic flow can probe the symmetry energy from the low-density region to the high-density region when changing the incident beam energies from 0.3 to 0.6 GeV/nucleon in the semi-central $^{132}$Sn+$^{124}$Sn reaction. And nucleon transverse and elliptic flows in the semi-central $^{197}$Au+$^{197}$Au reaction at 0.6 GeV/nucleon are more sensitive to the high-density behavior of the nuclear symmetry energy. One thus concludes that nucleon observables in the heavy reaction system and with higher incident beam energy are more suitable to be used to probe the high-density behavior of the symmetry energy. The present study may help one to get more specific information about the density-dependent symmetry energy from nucleon flow observable in heavy-ion collisions at intermediate energies.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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