Low moments of the four-loop splitting functions in QCD

Autor: S. Moch, B. Ruijl, T. Ueda, J.A.M. Vermaseren, A. Vogt
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Physics letters / B 825, 136853 (2022). doi:10.1016/j.physletb.2021.136853
Physics Letters
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 825
Physics Letters B, Vol 825, Iss, Pp 136853-(2022)
DOI: 10.1016/j.physletb.2021.136853
Popis: Physics letters / B 825, 136853 (2022). doi:10.1016/j.physletb.2021.136853
We have computed the four lowest even-N moments of all four splitting functions for the evolution of flavour-singlet parton densities of hadrons at the fourth order in the strong coupling constant αs. The perturbative expansion of these moments, and hence of the splitting functions for momentum fractions x≳0.1, is found to be well behaved with relative αs-coefficients of order one and sub-percent effects on the scale derivatives of the quark and gluon distributions at αs≲0.2. More intricate computations, including other approaches such as the operator-product expansion, are required to cover the full x-range relevant to LHC analyses. Our results are presented analytically for a general gauge group for detailed checks and validations of such future calculations.
Published by North-Holland Publ., Amsterdam
Databáze: OpenAIRE