中能重离子碰撞中库仑相互作用对动量耗散的同位旋效应

利用同位旋相关的量子分子动力学模型，研究了中能重离子碰撞过程中的库仑相互作用对于 动量耗散的同位旋效应.计算结果表明: 由于库仑相互作用的存在，使得碰撞过程中的化学 不稳定区和力学不稳定区减小，明显地减弱了动量耗散；其减弱的程度与对称势的形式及强 度有关，对称势越强则动量耗散的减弱幅度越大.动量耗散灵敏地依赖于核子-核子碰撞截 面的同位旋相关性而较弱地依赖于对称势，这一特征不论有无库仑相互作用均存在. 关键词： 中能重离子碰撞 库仑相互作用 动量耗散 同位旋效应

The isospin effects on the momentum dissipation induced by the Coulomb interacti on in the process of heavy-ion collissions

The isospin effects of Coulomb interaction on the momentum dissipation in the heavy ion collissions at an intermediate energy has been studied carefully within the isospin dependent quantum molecular dynamics model. The results show that Co ulomb interaction induces the reduction of momentum dissipation because it leads the shrinking of the mechanical and chemical instability domains, and the degre e of reduction depends sensitively on the form and strength of symmetry potentia l. However, the property that the momentum dissipation depends sensitively on th e isospin dependences of in-medium nucleon_nucleon cross section and insensitiv ely on the symmetry potential, is true for the cases with and without the Coulom b interaction.