J functions for the process ud→WA

Autor: E. Uglov, D.Yu. Bardin, W. von Schlippe, Lidia Kalinovskaya
Rok vydání: 2016
Předmět:
Zdroj: Physics of Atomic Nuclei. 79:95-107
ISSN: 1562-692X
1063-7788
Popis: In this paper we present a description of the universal approach for analytic calculations for a certain class of J functions for six topologies of the boxes for the process ud → WA. These functions J arise at the reduction of the infrared divergent box diagrams. The standard Passarino–Veltman reduction of the four-point box diagram with an internal photon line connecting two external lines on the mass shell leads to infrared-divergent and mass-singular D0 functions. In the system SANC a systematic procedure is adopted to separate both types of singularities into the simplest objects, namely C0 functions. The functions J, in turn, are represented as certain linear combinations of the standard D0 and C0 functions. The subtracted J functions are free of both types of singularities and are expressed as explicit and compact linear combinations of dilogarithm functions. We present extensive comparisons of numerical results of SANC with those obtained with the aid of the LoopTools package.
Databáze: OpenAIRE