0000000000204791
AUTHOR
D. Kreimer
ONE-LOOP INTEGRALS REVISITED — THE THREE-POINT FUNCTIONS
This paper presents results concerning a new calculation of the well-known one-loop n- point scalar and tensor functions. In this paper we treat the three-point functions. We give a systematic reduction to a certain class of functions which minimizes the effort for calculating scalar and tensor integrals drastically. We avoid standard techniques such as Feynman parametrization and Wick rotation.
oneloop 2.0 — A program package calculating one-loop integrals
We present an improved version of our program package oneloop which -- written as a package for MAPLE -- solves one-loop Feynman integrals. The package is calculating one-, two- and three-point functions both algebraically and numerically to any tensor rank. In addition to the original version oneloop 2.0 also calculates infrared divergent integrals. Higher powers of propagator terms and the $O(\eps)$ parts relevant for two-loop calculations are now supported.
A new method for computing one-loop integrals
We present a new program package for calculating one-loop Feynman integrals, based on a new method avoiding Feynman parametrization and the contraction due to Passarino and Veltman. The package is calculating one-, two- and three-point functions both algebraically and numerically to all tensor cases. This program is written as a package for Maple. An additional Mathematica version is planned later.
xloops - Automated Feynman diagram calculation
The program package xloops, a general, model independent tool for the calculation of high energy processes up to the two-loop level, is introduced. xloops calculates massive one- and two-loop Feynman diagrams in the standard model and related theories both analytically and numerically. A user-friendly Xwindows frontend is part of the package. xloops relies on the application of parallel space techniques. The treatment of tensor structure and the separation of divergences in analytic expressions is described in this scheme. All analytic calculations are performed with Maple. We describe the mathematical methods and computer algebra techniques xloops uses and give a brief introduction how to …