English

Multiple Mellin-Barnes integrals with straight contours

High Energy Physics - Phenomenology 2023-02-01 v1 High Energy Physics - Theory Mathematical Physics math.MP

Abstract

We show how the conic hull method, recently developed for the analytic and non-iterative evaluation of multifold Mellin-Barnes (MB) integrals, can be extended to the case where these integrals have straight contours of integration parallel to the imaginary axes in the complex planes of the integration variables. MB integrals of this class appear, for instance, when one computes the ϵ\epsilon-expansion of dimensionally regularized Feynman integrals, as a result of the application of one of the two main strategies (called A and B in the literature) used to resolve the singularities in ϵ\epsilon of MB representations. We upgrade the Mathematica package MBConicHulls.wl which can now be used to obtain multivariable series representations of multifold MB integrals with arbitrary straight contours, providing an efficient tool for the automatic computation of such integrals. This new feature of the package is presented, along with an example of application by calculating the ϵ\epsilon-expansion of the dimensionally regularized massless one-loop pentagon integral in general kinematics and D=42ϵD=4-2\epsilon.

Keywords

Cite

@article{arxiv.2212.11839,
  title  = {Multiple Mellin-Barnes integrals with straight contours},
  author = {Sumit Banik and Samuel Friot},
  journal= {arXiv preprint arXiv:2212.11839},
  year   = {2023}
}

Comments

17 pages, 2 figures, code repository: https://github.com/SumitBanikGit/MBConicHulls

R2 v1 2026-06-28T07:49:10.823Z