https://doi.org/10.1140/epjc/s10052-020-8131-3
Regular Article - Theoretical Physics
New series representations for the two-loop massive sunset diagram
1
Centre for High Energy Physics, Indian Institute of Science, Bangalore, Karnataka, 560012, India
2
Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405, Orsay, France
3
Univ Lyon, Univ Claude Bernard Lyon1, CNRS/IN2P3, IP2I Lyon, UMR 5822, F-69622, Villeurbanne, France
4
Helmholtz-Institut für Strahlen- und Kernphysik & Bethe Center for Theoretical Physics, Universität Bonn, D-53115, Bonn, Germany
* e-mail: shayanghosh@gmail.com
Received:
29
November
2019
Accepted:
9
June
2020
Published online:
4
July
2020
We derive new convergent series representations for the two-loop sunset diagram with three different propagator masses 
and 
and external momentum p by techniques of analytic continuation on a well-known triple series that corresponds to the Lauricella 
function. The convergence regions of the new series contain regions of interest to physical problems. These include some ranges of masses and squared external momentum values which make them useful from Chiral Perturbation Theory to some regions of the parameter space of the Minimal Supersymmetric Standard Model. The analytic continuation results presented for the Lauricella series could be used in other settings as well.
© The Author(s), 2020
