Four-loop splitting functions at small x
| Autor: | Marco Bonvini, Simone Marzani |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics
Nuclear and High Energy Physics Particle physics Logarithm 010308 nuclear & particles physics Computation Order (ring theory) FOS: Physical sciences QCD Phenomenology 01 natural sciences Loop splitting High Energy Physics - Phenomenology DGLAP High Energy Physics - Phenomenology (hep-ph) Scheme (mathematics) 0103 physical sciences Code (cryptography) lcsh:QC770-798 lcsh:Nuclear and particle physics. Atomic energy. Radioactivity Resummation 010306 general physics |
| Zdroj: | JHEP Journal of High Energy Physics, Vol 2018, Iss 6, Pp 1-38 (2018) Journal of High Energy Physics |
| Popis: | We consider the expansion of small-$x$ resummed DGLAP splitting functions at next-to-leading logarithmic (NLL) accuracy to four-loop order, namely next-to-next-to-next-to-leading order (N$^3$LO). From this, we extract the exact LL and NLL small-$x$ contributions to the yet unknown N$^3$LO splitting functions, both in the standard $\overline{MS}$ scheme and in the $Q_0 \overline{MS}$ scheme usually considered in small-$x$ literature. We show that the impact of unknown subleading logarithmic contributions (NNLL and beyond) at N$^3$LO is significant, thus motivating future work towards their computation. Our results will be also needed in future to match NLL resummation to N$^3$LO evolution. In turn, we propose an improved implementation of the small-$x$ resummation and therefore release a new version of the resummation code (HELL 3.0) which contains these changes. Comment: 34 pages, 5 figures, 2 appendices. Version published in JHEP |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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