中能重离子碰撞过程中的镜像核发射率

Mirror nucleui emissivity in heavy ion collisions

利用量子分子动力学模型研究了中能重离子碰撞中的镜像核发射率,选取4个稳定的轻反应系统(64Ge+64Ge,64Zn+64Zn,64Ni+64Ni,64Fe+64Fe)和5个稳定的重反应系统(124Ba+124Ba,124Xe+124Xe,124Te+124Te,124Sn+124Sn,124Cd+124Cd),分别研究了它们在不同的时间、对称势、入射能量、系统中质比下的镜像核发射率的特征。研究表明,不论轻、重反应系统,发射率Y(n)/Y(p)和镜像核发射率Y(3H)/Y(3He)都随着系统中质比的增大而增大。Y(n)/Y(p)为前平衡发射中子产额与质子产额之比,Y(3H)/Y(3He)为前平衡发射3H产额与3He产额之比。相对于发射率Y(n)/Y(p),同位旋相关平均场对镜像核发射率Y(3H)/Y(3He)更为灵敏。在重反应系统、缺中子反应系统中,镜像核发射率Y(3H)/Y(3He)作为同位旋相关平均场的灵敏探针更为合适。

The mirror nucleui emissivity in medium energy heavy ion collisions was studied by using a quantum molecular dynamics model.Four stable light nuclide reaction systems(64Ge+64Ge,64Zn+64Zn,64Ni+64Ni,64Fe+64Fe)and five stable heavy nuclide reaction systems(124Ba+124Ba,124Xe+124Xe,124Te+124Te,124Sn+124Sn,124Cd+124Cd)were selected to study the change of the characteristics of the mirror nucleui emissivity at different time,under different incident energy and with different system neutron-proton ratio.The results show that both the Y(n)/Y(p)ratio and the Y(3H)/Y(3He)ratio increase with the increase of the system neutron-proton ratio in both light and heavy reaction systems.Y(n)/Y(p)is the ratio of pre-equilibrium neutron yield to proton yield,Y(3H)/Y(3He)is the ratio of pre-equilibrium 3H yield to 3He yield.Compared with the Y(n)/Y(p)ratio,the isospindependent mean field is more sensitive to the Y(3H)/Y(3He)ratio.In the heavy reaction system and neutron deficient reaction system,the mirror nucleui emissivity Y(3H)/Y(3He)is more suitable as a sensitive probe for isospin-dependent mean field.