DOI: 10.1140/epjc/s10052-026-16303-w ISSN: 1434-6052
PDF evolution in alternative factorisation schemes
S. Delorme, A. Kusina, A. Siódmok, J. Whitehead Abstract
Beyond leading order, parton distribution functions (PDFs) require a choice of factorisation scheme to be defined unambiguously. Different choices of factorisation scheme lead to PDFs that satisfy modified DGLAP evolution equations, relative to the conventional
$$\overline{\textrm{MS}}$$
MS
¯
scheme. In this paper we derive the NLO DGLAP splitting functions for PDFs in alternative factorisation schemes, including for a parametrised scheme spanning a subspace of the general factorisation-scheme space. We plot their Mellin-space counterparts, the anomalous dimensions, and study the leading large- and small-
x
behaviour, relevant to resummation. We find that the leading behaviour admits a natural interpretation as a modified effective evolution scale. This is an essential step towards being able to evolve and fit PDFs in alternative schemes for use within QCD calculations.