标题： 一种具有共存味数PDF的FONLL方案 显示英文标题

标题： An FONLL prescription with coexisting flavor number PDFs

摘要： 我们提出了一种新的方法，用于在确定部分子分布函数（PDFs）时考虑重夸克质量效应，该方法基于FONLL方案。 我们的方法明确利用了在给定尺度下选择活性味数的自由度，从而可以使用具有不同活性味数的共存PDF。 这种新方法在微扰上等价于以前的方法，但在两个方面改进了实现方式。 首先，它可以自然地推广以同时考虑多个重夸克效应，例如奇夸克和底夸克效应，由于它们的质量差异较小，这些效应在相同尺度下都可能相关。 其次，它可以轻松推广到任何固定阶或共线重求和精度，而以前的方法需要为每个系数进行专门的DGLAP演化核展开。 我们补充了计算此新方法中深度非弹性散射可观测量的代码。 显示英文摘要

摘要： We present a new prescription to account for heavy quark mass effects in the determination of parton distribution functions (PDFs) based on the FONLL scheme. Our prescription makes explicit use of the freedom to choose the number of active flavors at a given scale and, thus, use coexisting PDFs with different active flavor number. This new prescription is perturbatively equivalent to the former but improves the implementation in two ways. First, it can be naturally generalized to account simultaneously for multiple heavy quark effects, such as charm and bottom effects, which can both be relevant at the same scale due to the small mass difference. Second, it can be trivially generalized to use at any fixed-order or collinear resummed accuracy, while previous prescriptions required ad-hoc expansions of the DGLAP evolution kernels for each coefficient. We supplement the paper with codes for the computation of deep inelastic scattering observables in this new prescription.