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arXiv 1509.04792nucl-th
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重离子碰撞中介质和同位旋对阈能附近粒子产生的影响

In-medium and isospin effects on particle production near threshold energies in heavy-ion collisions

Zhao-Qing Feng, Wen-Jie Xie, Peng-Hui Chen, Jie Chen, Gen-Ming Jin

摘要:

利用兰州量子分子动力学(LQMD)输运模型研究了阈能附近重离子碰撞中产生的赝标介子($π$、$η$、$K$和$\overline{K}$)和超子($Λ$和$Σ$)的动力学行为。通过对基本截面的修正和引入介子(超子)-核子势,并考虑了同位旋效应,实现了对致密核物质中粒子产生的介质内修正.结果表明,介质修正对粒子输运有一定的影响。π介子的总数随着同位旋、密度和动量的变化而减少。然而,带电π介子的比率与列入的潜力提高。在中快高动量区,η的产生对$η$ -核子势敏感,但对对称能的依赖性较弱。反K介子-核子相互吸引势增强了亚阈$\overline{K}$的产生,同时也影响了相空间分布的结构。由于π介子和核子之间的碰撞(共振),π介子势也会影响etas、K介子、反K介子和超子的动力学。研究了平均场势对粒子动力学的影响,如由快度谱、横动量谱、包容不变谱、集体流等得到的相空间分布。

英文摘要:

Dynamics of pseudoscalar mesons ($π$, $η$, $K$ and $\overline{K}$ ) and hyperons ($Λ$ and $Σ$) produced in heavy-ion collisions near threshold energies has been investigated within the Lanzhou quantum molecular dynamics (LQMD) transport model. The in-medium modifications on particle production in dense nuclear matter are implemented in the model through corrections on the elementary cross sections and by inclusion of the meson (hyperon)-nucleon potentials, in which the isospin effects are considered. It is found that the transportation of particles are influenced with the in-medium corrections. The total number of pions is reduced with an isospin, density and momentum dependent pion-nucleon potential. However, the ratios of charged pions is enhanced with inclusion of the potential. The production of eta in the domain of mid-rapidities and high momenta is sensitive to the $η$-nucleon potential, but weakly depends on symmetry energy. The attractive antikaon-nucleon potential enhances the subthreshold $\overline{K}$ production and also influences the structure of phase-space distributions. Dynamics of etas, kaons, antikaons and hyperons is also influenced by the pion potential because of collisions between pions and nucleons (resonances). The impacts of mean-field potentials on particle dynamics are investigated, such as the phase-space distributions from rapidity and transverse momentum spectra, inclusive invariant spectra, collective flows etc.

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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