Expansion by regions meets angular integrals

Fuente: arXiv
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Autori principali: Smirnov, Vladimir A., Wunder, Fabian
Natura: Preprint
Pubblicazione: 2024
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author Smirnov, Vladimir A.
Wunder, Fabian
author_facet Smirnov, Vladimir A.
Wunder, Fabian
contents We study the small-mass asymptotic behavior of so-called angular integrals, appearing in phase-space calculations in perturbative quantum field theory. For this purpose we utilize the strategy of expansion by regions, which is a universal method both for multiloop Feynman integrals and various parametric integrals. To apply the technique to angular integrals, we convert them into suitable parametric integral representations, which are accessible to existing automation tools. We use the the code \texttt{asy.m} to reveal regions contributing to the asymptotic expansion of angular integrals. To evaluate the contributions of these regions in an epsilon expansion we apply the method of Mellin-Barnes representation. Our approach is checked against existing results on angular integrals revealing a connection between contributing regions and angular integrals constructed from an algebraic decomposition. We explicitly calculate the previously unknown asymptotics for angular integrals with three and four denominators and formulate a conjecture for the leading asymptotics and the pole part for a general number of denominators and masses.
format Preprint
id arxiv_https___arxiv_org_abs_2405_13120
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Expansion by regions meets angular integrals
Smirnov, Vladimir A.
Wunder, Fabian
High Energy Physics - Phenomenology
High Energy Physics - Theory
We study the small-mass asymptotic behavior of so-called angular integrals, appearing in phase-space calculations in perturbative quantum field theory. For this purpose we utilize the strategy of expansion by regions, which is a universal method both for multiloop Feynman integrals and various parametric integrals. To apply the technique to angular integrals, we convert them into suitable parametric integral representations, which are accessible to existing automation tools. We use the the code \texttt{asy.m} to reveal regions contributing to the asymptotic expansion of angular integrals. To evaluate the contributions of these regions in an epsilon expansion we apply the method of Mellin-Barnes representation. Our approach is checked against existing results on angular integrals revealing a connection between contributing regions and angular integrals constructed from an algebraic decomposition. We explicitly calculate the previously unknown asymptotics for angular integrals with three and four denominators and formulate a conjecture for the leading asymptotics and the pole part for a general number of denominators and masses.
title Expansion by regions meets angular integrals
topic High Energy Physics - Phenomenology
High Energy Physics - Theory
url https://arxiv.org/abs/2405.13120