TY  - EJOUR
AU  - Moch, Sven-Olaf
AU  - Ruijl, Ben
AU  - Ueda, Takahiro
AU  - Vogt, Andreas
AU  - Vermaseren, Jos
TI  - Low moments of the four-loop splitting functions in QCD
IS  - DESY-21-203
M1  - PUBDB-2021-04837
M1  - DESY-21-203
M1  - NIKHEF 21-030
M1  - LTH 1282
M1  - arXiv:2111.15561
N1  - 11 pages, LaTeX, 2 figures. Analytical results in ancillary FORM file
AB  - 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 α<sub>s</sub>. 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 α<sub>s</sub>-coefficients of order one and sub-percent effects on the scale derivatives of the quark and gluon distributions at α<sub>s</sub>  <~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.
KW  - strong interaction: coupling constant (INSPIRE)
KW  - parton: density (INSPIRE)
KW  - evolution equation (INSPIRE)
KW  - DGLAP equation (INSPIRE)
KW  - splitting function (INSPIRE)
KW  - operator product expansion (INSPIRE)
KW  - quantum chromodynamics (INSPIRE)
KW  - quark (INSPIRE)
KW  - gluon (INSPIRE)
KW  - perturbation theory (INSPIRE)
KW  - higher-order: 4 (INSPIRE)
KW  - Mellin transformation (INSPIRE)
LB  - PUB:(DE-HGF)25
UR  - https://bib-pubdb1.desy.de/record/472098
ER  -