Loop Integrals, R Functions and their Analytic Continuation

Abstract

To entirely determine the resulting functions of one-loop integrals it is necessary to find the correct analytic continuation to all relevant kinematical regions. We argue that this continuation procedure may be performed in a general and mathematical accurate way by using the ${\cal R}$ function notation of these integrals. The two- and three-point cases are discussed explicitly in this manner.Comment: 10 pages (Latex), MZ-TH/93-1