We report on the first measurement of the elemental fragmentation cross sections (EFCSs) of Si29−33 on a carbon target at ∼230 MeV/nucleon. The experimental data covering charge changes of ΔZ = 1-4 are reproduced well by the isospin-dependent quantum molecular dynamics (IQMD) coupled with the evaporation GEMINI (IQMD+GEMINI) model. We further explore the mechanisms underlying the single-proton removal reaction in this model framework. We conclude that the cross sections from direct proton knockout exhibit an overall weak dependence on the mass number of Si projectiles. The proton evaporation induced after the projectile excitation significantly affects the cross sections for neutron-deficient Si isotopes, while neutron evaporation plays a crucial role in the reactions of neutron-rich Si isotopes. It is presented that the relative magnitude of one-proton and one-neutron separation energies is an essential factor that influences evaporation processes. Therefore, proton evaporation should be incorporated into the reaction model in addition to the direct proton knockout in analyses of Gade-Tostevin systematic for single-proton removal reactions.

中文翻译：

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IQMD+GEMINI 模型中的单质子去除反应，以 ∼230 MeV/核子下碳上 29-33Si 的元素碎裂截面为基准


我们报告了在 ∼230 MeV/核子的碳靶上首次测量 Si29-33 的元素碎裂截面 （EFCS）。涵盖 ΔZ = 1-4 电荷变化的实验数据通过同位素依赖性量子分子动力学 （IQMD） 与蒸发 GEMINI （IQMD+GEMINI） 模型耦合得到了很好的再现。我们在这个模型框架中进一步探讨了单质子去除反应的潜在机制。我们得出结论，直接质子敲除的横截面对 Si 弹丸质量数的总体依赖性较弱。弹丸激发后诱导的质子蒸发显着影响中子缺陷 Si 同位素的横截面，而中子蒸发在富中子 Si 同位素的反应中起着至关重要的作用。文中提出，单质子和单中子分离能的相对大小是影响蒸发过程的重要因素。因此，在用于单质子去除反应的 Gade-Tostevin 系统分析中，除了直接敲除质子外，还应将质子蒸发纳入反应模型。