标题： 6,7Li和7Be核在统一电弱理论中的电子散射截面 显示英文标题

标题： Electron scattering cross sections for 6,7Li and 7Be nuclei within the unified electroweak theory

摘要： 本研究在统一的弱电理论中采用多极展开来研究电子与6,7Li和7Be核的散射截面。 在散射截面表达式中的多极形式因子是直接基于多粒子壳模型和分数母体系数计算的，而没有使用任何近似。 所得结果表明，当入射电子的能量不超过核子质量的两倍时，传统的冲击近似才能应用于电子-核子散射。 此外，7Li从基态到最近激发态的准弹性散射截面以及基态的弹性散射截面被分别处理，而实验中尚未分别测量这些截面。 使用V-A结构计算的散射截面在低（MeV）能量下与现有的实验数据相符，并在高（GeV）能量下提供了预测信息。 发现所有情况下散射截面随着入射电子能量和散射角的增加而迅速减小。 特别是，在数百GeV及更高能量下，只有前向散射过程。 此外，通过比较某一能量和散射角下三种被研究核的弹性截面，清楚地展示了核大小与核子数成正比的规律。 显示英文摘要

摘要： The present study employs the multipole expansion within the unified electroweak theory to investigate the electron scattering cross sections for 6,7Li and 7Be nuclei. The multipole form factors presented in the expressions of the cross sections are directly calculated based on the many-particle shell model and fractional parentage coefficients without using any approximations. The results obtained indicate that the conventional impulse approximation can be applied to the electron-nucleus scattering only when the energy of incident electrons does not exceed twice the nucleon mass. In addition, the quasi-elastic scattering cross section of 7Li in the excitation from its ground state to the nearest excited state and that of elastic scattering in the ground state are independently treated, whereas they have not been separately measured in experiments. The calculated scattering cross sections using the V-A structure agree reasonably well with the available experimental data at low (MeV) energies and provide predictive information at high (GeV) energies. The scattering cross sections are found to rapidly decrease in all cases with increasing the incident electron energy and scattering angle. In particular, at the energies of hundreds of GeV and higher, there are only the forward scattering processes. Furthermore, by comparing the elastic cross sections of three investigated nuclei at a certain energy and scattering angle, the rule that the nuclear size is proportional to the number of nucleons is clearly shown.