Speaker
Prof.
Elise de Doncker
(Western Michigan University)
Description
The paper will include numerical integration results
for Feynman loop diagrams through 3-loop such as
those covered by (Laporta, 2000). While Laporta
generated solutions by solving systems of difference
equations, the current methods are based on automatic
adaptive integration, using iterated integration
with programs from the QuadPack package, or multivariate
techniques from the ParInt package. The QuadPack programs
have been parallelized with OpenMP for multicore systems.
In particular, the Dqags algorithm allows handling boundary
singularities of fairly general types. ParInt is a package
for multivariate integration layered over MPI (Message
Passing Interface), which runs on clusters and incorporates
advanced parallel/distributed techniques such as load
balancing among processes that may be distributed over
a network of nodes. We will give results for 3-loop
self-energy diagrams without IR (infra-red) or UV
(ultra-violet) singularities, and 2-loop self-energy
diagrams with UV terms. The latter can be treated with
automatic numerical integration allowing for boundary
singularities, and numerical extrapolation. These cases
include 2-loop self-energy diagrams with three, four
and five internal lines.
Author
Prof.
Elise de Doncker
(Western Michigan University)
Co-authors
Dr
Fukuko Yuasa
(High Energy Accelerator Research Organization (KEK), Japan)
Prof.
Kiyoshi Kato
(Kogakuin University)
Mrs
Omofalakunmi (Fola) Olagbemi
(Western Michigan University)
Dr
Tadashi Ishikawa
(High Energy Accelerator Research Organization (KEK), Japan)
