论文标题
$ \ Overline {\ rm {ms}} $ parton发行量为负吗？
Can $\overline{\rm { MS}}$ parton distributions be negative?
论文作者
论文摘要
普遍的知识是，由于沿线扣除，$ \叠加{\ rm {ms}} $分解方案中的parton分布函数（PDF）可能会超出领先顺序，这是为了定义partocononic横截面所需的。我们表明，事实并非如此，次要领先顺序（NLO）$ \ OVERLINE {\ rm {MS}} $ PDFS实际上在扰动方面是积极的。为了证明这一点，我们修改了减法处方，并以党派横截面保持积极的方式执行共线减法。这定义了一个分解方案，其中PDF是阳性的。然后，我们表明，从该方案转换为$ \ overline {\ rm {ms}} $时，保留了PDF的阳性，仅提供强耦合在扰动方面，以使NLO方案更改的变化小于LO术语。
It is common lore that Parton Distribution Functions (PDFs) in the $\overline{\rm { MS}}$ factorization scheme can become negative beyond leading order due to the collinear subtraction which is needed in order to define partonic cross sections. We show that this is in fact not the case and next-to-leading order (NLO) $\overline{\rm { MS}}$ PDFs are actually positive in the perturbative regime. In order to prove this, we modify the subtraction prescription, and perform the collinear subtraction in such a way that partonic cross sections remain positive. This defines a factorization scheme in which PDFs are positive. We then show that positivity of the PDFs is preserved when transforming from this scheme to $\overline{\rm { MS}}$, provided only the strong coupling is in the perturbative regime, such that the NLO scheme change is smaller than the LO term.
