Broken conformal invariance and spectrum of anomalous dimensions in QCD

Andrei Belitsky, D. Müller

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113 Scopus citations

Abstract

Employing the operator algebra of the conformai group and the conformai Ward identities, we derive the constraints for the anomalies of dilatation and special conformai transformations of the local twist-2 operators in Quantum Chromodynamics. We calculate these anomalies in the leading order of perturbation theory in the minimal subtraction scheme. From the conformai consistency relation we derive then the off-diagonal part of the anomalous dimension matrix of the conformally covariant operators in the two-loop approximation of the coupling constant in terms of these quantities. We deduce corresponding off-diagonal parts of the Efremov-Radyushkin-Brodsky-Lepage kernels responsible for the evolution of the exclusive distribution amplitudes and non-forward parton distributions in the next-to-leading order in the flavour singlet channel for the chiral-even parity-odd and -even sectors as well as for the chiral-odd one. We also give the analytical solution of the corresponding evolution equations exploiting the conformai partial wave expansion.

Original languageEnglish (US)
Pages (from-to)397-442
Number of pages46
JournalNuclear Physics B
Volume537
Issue number1-3
Publication statusPublished - Jan 4 1999
Externally publishedYes

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Keywords

  • Anomalous dimensions
  • Conformal anomalies
  • Conformal Ward identities
  • Evolution equations

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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