AI 中文总结
本研究通过39组新的电荷改变截面数据，揭示了标度因子的普适依赖关系，发现铅这类重靶是确定不稳定原子核质子分布半径的最佳选择。
AI 中文摘要
我们发现，通过电荷改变截面（σ_cc）测量来确定不稳定原子核的质子分布半径时，铅（Pb）这类重靶最为适用。作为重离子探针，低Z靶通常用于确定不稳定同位素的核子分布半径，该方法近期已被扩展到通过σ_cc测量研究质子分布半径，但应用Glauber模型时必须引入经验标度因子。本研究利用约240 MeV/核子能量下，18个p壳层核在氢、碳、银和铅靶上的39组新σ_cc数据，系统研究了标度因子，结合现有数据揭示了标度因子对靶核质量和射核分离能的普适依赖关系：标度因子随靶核质量增大而减小，在最高Z靶时收敛至1，无需再进行标度。我们得出结论：在σ_cc测量中，应采用铅这类重靶而非低Z靶，这是确定不稳定原子核质子分布半径的最佳选择。
英文摘要
We found that a heavy target such as Pb is most suitable for determining the proton distribution radii of unstable nuclei through charge-changing cross-section ($σ_\text{cc}$) measurements. As a heavy ion probe, low-$Z$ targets are routinely used to determine nucleon distribution radii of unstable isotopes. This approach has recently been extended to study proton distribution radii from $σ_\text{cc}$ measurements. However, empirical scaling factors have to be introduced to apply the Glauber models. In the present work, we systematically investigated the scaling factor using 39 new $σ_\text{cc}$ data of 18 $p$-shell nuclei on hydrogen, carbon, silver, and lead targets at around 240 MeV/nucleon. Together with the existing data, we reveal a universal dependence of the scaling factor on both the masses of target nuclei and the separation energies of projectile nuclei. The scaling factors decrease with increasing target-nucleus mass and converge to 1 for the highest-$Z$ target, making the scaling unnecessary. We conclude that instead of a low-$Z$ target, employing a heavy target such as Pb in $σ_\text{cc}$ measurements is the best option to determine the proton distribution radii of unstable nuclei.
