Nucleon effective mass splitting and density-dependent symmetry energy effects on elliptic flow in heavy ion collisions at Elab=0.09 ～ 1.5 GeV/nucleon

• 来源期刊: 中国物理C（英文版）
• 年，卷（期）: 2020,（7）
• 页码范围: 103-110
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1137/44/7/074103

摘要

By incorporating an isospin-dependent form of the momentum-dependent potential in the ultra-relativistic quantum molecular dynamics (UrQMD) model,we systematically investigate effects of the neutron-proton effective mass splitting m*n-p=m*n-m*p/ m and the density-dependent nuclear symmetry energy Esym(9) on the elliptic flow v2 in 197Au + 197Au collisions at beam energies from 0.09 to 1.5 GeV/nucleon.It is found that at higher beam energies (≥0.25 GeV/nucleon) with the approximately 75 MeV difference in slopes of the two different Esym(ρ),and the variation of m* ranging from-0.03 to 0.03 at saturation density with isospin asymmetry δ =(ρn-ρp)/ρ =0.2,the Esym(ρ) has a stronger influence on the difference in v2 between neutrons and protons,i.e.,vn2-vp2,than m*n-p has.Meanwhile,at lower beam energies (≤ 0.25 GeV/nucleon),v n2-vp2 is sensitive to both the Esym(ρ) and the m*n-p.Moreover,the influence of m*n-p on vn2-vp2 is more evident with the parameters of this study when using the soft,rather than stiff,symmetry energy.