By considering different values of the time-step for the potential updates in the ultra-relativistic quantum molecular dynamics(UrQMD) model, we examine its influence on observables, such as the yield and collective f...By considering different values of the time-step for the potential updates in the ultra-relativistic quantum molecular dynamics(UrQMD) model, we examine its influence on observables, such as the yield and collective flow of nucleons and pions from heavyion collisions around 1 GeV/nucleon. It is found that these observables are affected to some extent by the choice of the time-step,and the impact of the time-step on the pion-related observables is more visible than that on the nucleon-related ones. However,its effect on the π-/π+yield ratio and elliptic flow difference between neutrons and protons, which have been taken as sensitive observables for probing the density-dependent nuclear symmetry energy at high densities, is fairly weak.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11505057, 11547312, 11375062, and 11605270)the Department of Education of Zhejiang Province (Grant No. Y201533176)+1 种基金the China Postdoctoral Special Science Foundation (Grant No. 2016M591730)support by the computing server C3S2 in Huzhou University
文摘By considering different values of the time-step for the potential updates in the ultra-relativistic quantum molecular dynamics(UrQMD) model, we examine its influence on observables, such as the yield and collective flow of nucleons and pions from heavyion collisions around 1 GeV/nucleon. It is found that these observables are affected to some extent by the choice of the time-step,and the impact of the time-step on the pion-related observables is more visible than that on the nucleon-related ones. However,its effect on the π-/π+yield ratio and elliptic flow difference between neutrons and protons, which have been taken as sensitive observables for probing the density-dependent nuclear symmetry energy at high densities, is fairly weak.
