$\{β\}$-expansion in QCD, its conformal symmetry limit: theory + applications

A. L. Kataev; S. V. Mikhailov

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arXiv · 1410.0554

$\{β\}$-expansion in QCD, its conformal symmetry limit: theory + applications

A. L. Kataev·S. V. Mikhailov

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Abstract

The basis of the $\{β\}$-expansion for the perturbative series evaluated in the $\overline{MS}$ scheme for the renormalization group invariant quantities is summarized.Comparison with a similar representation,used within the BLM-motivated Principle of Maximal Conformality,is discussed.We stress that the original $\{β\}$-expansion contains a completed list of terms rather than its PMC analog. The arguments in favour of the complete $\{β\}$-expansion are presented. They are based on the relations which follow from the power $β$-function generalization of the Crewther relation for the nonsinglet $\overline{MS}$ contributions to the Adler $D^{NS}$-functionand to the Bjorken sum rule $C^{Bjp}_{NS}$ of the polarized lepton-nucleon scattering. The terms of the complete $\{β\}$-expansionat the $O(α_s^3)$ level for $D^{NS}$ and $C^{Bjp}_{NS}$ are presented. These perturbative results are expressed in the PMC-type form. The problem of applications of these expressions for phenomenological applications is summarized.

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A. L. Kataev, S. V. Mikhailov. 2015-01-17. $\{β\}$-expansion in QCD, its conformal symmetry limit: theory + applications. https://arxiv.org/abs/1410.0554

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