The virtual photon theory (VPT), which is based on first-order Coulomb dissociation restricted to the electric dipole (E1), has been successfully used to explain the breakup data for several cases. Our aim is to study the role of various higher-order processes that are ignored in the VPT, such as the nuclear breakup, interference between nuclear and Coulomb amplitudes, and multistep breakup processes mainly due to strong continuum-continuum couplings in the breakup of two-body projectiles on a heavy target at both intermediate and higher incident energies. For the purpose of numerical calculations, we employed eikonal version of three-body continuum-discretized coupled-channels (CDCC) reaction model. Our results for the breakup of 11Be and 17F on 208Pb target at 100, 250, and 520 MeV/A, show the importance of nuclear breakup contribution, and its significant role in the multistep processes. The multistep effect on Coulomb breakup for core-neutron projectile was found to be negligible, whereas it was important for core-proton projectile. Coulomb-nuclear interference (CNI) effect was also found to be non-negligible. Qantitatively, the multistep effects due to the nuclear breakup was found to depend on the incident energy through the energy dependence of the core-target and nucleon-target nuclear potentials. The nuclear breakup component, the CNI effect, and the multistep breakup processes are all found to be non-negligible; hence, the assumptions adopted in the VPT for the accurate description of breakup cross sections are not valid.

中文翻译：

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各种高阶过程在弱束缚弹体破体中作用的系统研究

基于限制在电偶极子 (E1) 的一阶库仑解离的虚光子理论 (VPT) 已成功地用于解释几种情况下的分裂数据。我们的目的是研究在 VPT 中被忽略的各种高阶过程的作用，例如核分裂、核和库仑振幅之间的干扰，以及主要由于强连续 - 连续耦合在两个分裂中的多步分裂过程- 以中等和较高的入射能量向重型目标发射体弹丸。出于数值计算的目的，我们采用了 eikonal 版本的三体连续离散耦合通道 (CDCC) 反应模型。我们的 11Be 和 17F 在 100、250 和 520 MeV/A 的 208Pb 靶上的解体结果显示了核解体贡献的重要性，及其在多步骤过程中的重要作用。发现核心-中子弹丸对库仑破裂的多步效应可以忽略不计，而对于核心-质子弹丸则很重要。库仑核干扰 (CNI) 效应也被发现是不可忽略的。定量地，通过核心靶和核子靶核势的能量依赖性，发现由于核分裂引起的多步效应取决于入射能量。核分裂成分、CNI 效应和多步分裂过程都被发现是不可忽略的；因此，VPT 中为准确描述解体横截面而采用的假设是无效的。而它对于核心质子弹丸很重要。库仑核干扰 (CNI) 效应也被发现是不可忽略的。定量地，通过核心靶和核子靶核势的能量依赖性，发现由于核分裂引起的多步效应取决于入射能量。核分裂成分、CNI 效应和多步分裂过程都被发现是不可忽略的；因此，VPT 中为准确描述解体横截面而采用的假设是无效的。而它对于核心质子弹丸很重要。库仑核干扰 (CNI) 效应也被发现是不可忽略的。定量地，通过核心靶和核子靶核势的能量依赖性，发现由于核分裂引起的多步效应取决于入射能量。核分裂成分、CNI 效应和多步分裂过程都被发现是不可忽略的；因此，VPT 中为准确描述解体横截面而采用的假设是无效的。通过核心靶和核子靶核势的能量依赖性，发现由于核分裂引起的多步效应取决于入射能量。核分裂成分、CNI 效应和多步分裂过程都被发现是不可忽略的；因此，VPT 中为准确描述解体横截面而采用的假设是无效的。通过核心靶和核子靶核势的能量依赖性，发现由于核分裂引起的多步效应取决于入射能量。核分裂成分、CNI 效应和多步分裂过程都被发现是不可忽略的；因此，VPT 中为准确描述解体横截面而采用的假设是无效的。