标题： MARATHON 数据对\texorpdfstring{$F_{2n}/F_{2p}$}{F2n/F2p}及轻核的非定域效应的影响 显示英文标题

标题： Impact of the MARATHON data on \texorpdfstring{$F_{2n}/F_{2p}$}{F2n/F2p} and off-shell effects in light nuclei

摘要： 中子结构函数$F_{2n}$历史上是从 deuteron（氘核）结构函数的测量中提取出来的，但我们在理解束缚质子和中子的核效应方面存在局限性，这限制了$F_{2n}$的提取。 MARATHON 合作组最近通过比较$^3$H 和$^3$He 靶标提取了$F_{2n}$，尽管这些核效应较大但几乎相同，从而得到了$F_{2n}/F_{2p}$的精确提取。 然后可以将这一精确提取与氘核提取进行比较，为氘核中的核效应提供重要的约束条件。 为了确保这种比较不会因 MARATHON 使用的具体核效应模型而产生偏差，我们考察了一系列核效应模型，以获得一种更保守且更独立于具体模型的$F_{2n}/F_{2p}$提取值，用于与氘核提取进行对比。 即便采用更保守的方法，比较结果仍表明需要显著的非定域修正或其他核效应，即使对于弱束缚态的氘核而言，在大多数计算中也未包含这些效应。 显示英文摘要

摘要： The neutron structure function, $F_{2n}$, has historically been extracted from measurements of the deuteron structure function, but our understanding of the nuclear effects on the bound proton and neutron limits the extraction of $F_{2n}$. The MARATHON collaboration recently extracted $F_{2n}$ from the comparison of $^3$H and $^3$He targets, where the nuclear effects are larger but nearly identical, yielding a precise extraction of $F_{2n}/F_{2p}$. This precise extraction can then be compared to deuteron extractions, providing important constraints on the nuclear effects in the deuteron. To ensure that this comparison is not biased by the specific model of nuclear effects used by MARATHON, we examine a range of models of the nuclear effects to obtain a more conservative, but more model-independent, extraction of $F_{2n}/F_{2p}$ for comparison with deuteron extractions. Even with the more conservative approach, the comparison suggests the need for significant off-shell corrections or other nuclear effects, beyond those include in most calculations, even for the weakly-bound deuteron.