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

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

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 .

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 Coulomb interaction induces the reduction of momentum dissipation because it leads the shrinking of the mechanical and chemical instability domains, and the degree of reduction depends sensitively on the form and strength of symmetry potential. However, the property that the momentum dissipation depends sensitively on the isospin dependences of in-medium nucleon-nucleon cross section and insensitively on the symmetry potential, is true for the cases with and without the Coulomb interaction.