The cross section for deep inelastic lepton-proton scattering (DIS) $\ell p\to {\ell }^{\prime }X$ includes a diffractive deep inelastic (DDIS) contribution $\ell p\to {\ell }^{\prime }{p}^{\prime }X$, in which the proton remains intact with a large longitudinal momentum fraction $x_F$ greater than 0.9 and small transverse momentum. The DDIS events, which can be identified with Pomeron exchange in the t-channel, account for approximately 10% of all of the DIS events. Thus, when one measures DIS, one automatically includes the leading-twist Bjorken-scaling DDIS events as a contribution to the DIS cross section, whether or not the final-state proton $p^{\prime }$ is detected. In such events, the missing momentum fraction $x_{p^{\prime }}\sim 0.9$ carried by the final-state proton $p^{\prime }$ in the DDIS events could be misidentified with the light-front momentum fraction carried by sea quarks or gluons in the protons' Fock structure. As we shall show in this article, the underlying QCD Pomeron-exchange amplitude which produces the DDIS events does not obey the operator product expansion nor satisfy momentum sum rules. Thus we conclude that the quark and gluon distributions measured in DIS experiments will be misidentified, unless the measurements explicitly exclude the DDIS events and that a correct determination of the parton distribution functions (PDFs) derived from the DIS data requires the explicit subtraction of the DDIS contribution from the full DIS cross section.

深度非弹性轻子 - 质子散射 (DIS) 的横截面 $\ell p\to {\ell }^{\prime }X$ 包括衍射深非弹性 (DDIS) 贡献 $\ell p\to {\ell }^{\prime }{p}^{\prime }X$，其中质子保持完整，具有较大的纵向动量分数 $X_F$大于 0.9，横向动量小。DDIS 事件可通过t通道中的波梅隆交换识别，约占所有 DIS 事件的 10%。因此，当测量 DIS 时，无论最终状态质子是否为$p^{\prime }$被检测到。在这种情况下，缺失的动量分数$X_{p^{\prime }}～0.9$ 由终态质子携带 $p^{\prime }$在 DDIS 事件中，质子的 Fock 结构中的海夸克或胶子携带的光前动量分数可能会被错误地识别。正如我们将在本文中展示的，产生 DDIS 事件的基础 QCD Pomeron-exchange 振幅不服从算子乘积扩展，也不满足动量和规则。因此，我们得出结论，DIS 实验中测量的夸克和胶子分布将被错误识别，除非测量明确排除 DDIS 事件，并且正确确定从 DIS 数据导出的部分子分布函数 (PDF) 需要明确减去 DDIS来自完整 DIS 横截面的贡献。