English

Dimensional recurrence relations: an easy way to evaluate higher orders of expansion in $\epsilon$

High Energy Physics - Phenomenology 2015-03-17 v2 High Energy Physics - Theory

Abstract

Applications of a method recently suggested by one of the authors (R.L.) are presented. This method is based on the use of dimensional recurrence relations and analytic properties of Feynman integrals as functions of the parameter of dimensional regularization, dd. The method was used to obtain analytical expressions for two missing constants in the ϵ\epsilon-expansion of the most complicated master integrals contributing to the three-loop massless quark and gluon form factors and thereby present the form factors in a completely analytic form. To illustrate its power we present, at transcendentality weight seven, the next order of the ϵ\epsilon-expansion of one of the corresponding most complicated master integrals. As a further application, we present three previously unknown terms of the expansion in ϵ\epsilon of the three-loop non-planar massless propagator diagram. Only multiple ζ\zeta values at integer points are present in our result.

Keywords

Cite

@article{arxiv.1005.0362,
  title  = {Dimensional recurrence relations: an easy way to evaluate higher orders of expansion in $\epsilon$},
  author = {Roman N. Lee and Alexander V. Smirnov and Vladimir A. Smirnov},
  journal= {arXiv preprint arXiv:1005.0362},
  year   = {2015}
}

Comments

Talk given at the International Workshop `Loops and Legs in Quantum Field Theory' (April 25--30, 2010, W\"orlitz, Germany).