English

Two-loop two-point functions with masses: asymptotic expansions and Taylor series, in any dimension

High Energy Physics - Phenomenology 2011-08-17 v1

Abstract

In all mass cases needed for quark and gluon self-energies, the two-loop master diagram is expanded at large and small q2q^2, in dd dimensions, using identities derived from integration by parts. Expansions are given, in terms of hypergeometric series, for all gluon diagrams and for all but one of the quark diagrams; expansions of the latter are obtained from differential equations. Pad\'{e} approximants to truncations of the expansions are shown to be of great utility. As an application, we obtain the two-loop photon self-energy, for all dd, and achieve highly accelerated convergence of its expansions in powers of q2/m2q^2/m^2 or m2/q2m^2/q^2, for d=4d=4.

Keywords

Cite

@article{arxiv.hep-ph/9304303,
  title  = {Two-loop two-point functions with masses: asymptotic expansions and Taylor series, in any dimension},
  author = {D. J. Broadhurst and J. Fleischer and O. V. Tarasov},
  journal= {arXiv preprint arXiv:hep-ph/9304303},
  year   = {2011}
}

Comments

25 pages, OUT--4102--43, BI--TP/92--57