Two-Loop Diagrams in Causal Perturbation Theory

Abstract

The scalar two-loop master diagram is revisited in the massive cases needed for the computation of boson and fermion propagators in QED and QCD. By means of the causal method it is possible in a straightforward manner to express the propagators as double integrals. In the case of vacuum polarization both integrations can be carried out in terms of polylogarithms, whereas the last integral in the fermion propagator cannot be expressed by known special functions. The advantage of the method in comparison with Feynman integral calculations is indicated.

16 pages, latex, the figures can be ordered at the first authors address (A.Aste), the necessary macros are included in the latex-file

References in corpus (1)

• Reduction of general two-loop self-energies to standard scalar integrals

Cited by in corpus (12)

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• Finite calculation of divergent selfenergy diagrams
• Scalar Matter Coupled to Quantum Gravity in the Causal Approach: Finite One-Loop Calculations and Perturbative Gauge Invariance
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• Resummation of mass terms in perturbative massless quantum field theory
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• Dispersive calculation of the massless multi-loop sunrise diagram
• Causal construction of the massless vertex diagram