Header

UZH-Logo

Maintenance Infos

The two-loop five-particle amplitude in N = 8 supergravity


Chicherin, Dmitry; Gehrmann, Thomas; Henn, Johannes M; Wasser, Pascal; Zhang, Yang; Zoia, Simone (2019). The two-loop five-particle amplitude in N = 8 supergravity. Journal of High Energy Physics, 2019(3):115.

Abstract

We compute for the first time the two-loop five-particle amplitude in N = 8 supergravity. Starting from the known integrand, we perform an integration-by-parts reduction and express the answer in terms of uniform weight master integrals. The latter are known to evaluate to non-planar pentagon functions, described by a 31-letter symbol alphabet. We express the final result for the amplitude in terms of uniform weight four symbols, multiplied by a small set of rational factors. We observe that one of the symbol letters is absent from the amplitude. The latter satisfies the expected factorization properties when one external graviton becomes soft, and when two external gravitons become collinear. We verify that the soft divergences of the amplitude exponentiate. We extract the finite remainder function, which depends on fewer rational factors. By analyzing identities involving rational factors and symbols we find a remarkably compact representation in terms of a single seed function, summed over all permutations of external particles. Finally, we work out the multi-Regge limit, and present explicitly the leading logarithmic terms in the limit. The full symbol of the IR-subtracted hard function is provided as a supplementary file.

Abstract

We compute for the first time the two-loop five-particle amplitude in N = 8 supergravity. Starting from the known integrand, we perform an integration-by-parts reduction and express the answer in terms of uniform weight master integrals. The latter are known to evaluate to non-planar pentagon functions, described by a 31-letter symbol alphabet. We express the final result for the amplitude in terms of uniform weight four symbols, multiplied by a small set of rational factors. We observe that one of the symbol letters is absent from the amplitude. The latter satisfies the expected factorization properties when one external graviton becomes soft, and when two external gravitons become collinear. We verify that the soft divergences of the amplitude exponentiate. We extract the finite remainder function, which depends on fewer rational factors. By analyzing identities involving rational factors and symbols we find a remarkably compact representation in terms of a single seed function, summed over all permutations of external particles. Finally, we work out the multi-Regge limit, and present explicitly the leading logarithmic terms in the limit. The full symbol of the IR-subtracted hard function is provided as a supplementary file.

Statistics

Citations

Dimensions.ai Metrics
14 citations in Web of Science®
13 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

25 downloads since deposited on 22 May 2019
25 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Physics Institute
Dewey Decimal Classification:530 Physics
Uncontrolled Keywords:Nuclear and High Energy Physics
Language:English
Date:1 March 2019
Deposited On:22 May 2019 12:16
Last Modified:25 Sep 2019 00:35
Publisher:Springer
ISSN:1029-8479
OA Status:Gold
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.1007/jhep03(2019)115

Download

Gold Open Access

Download PDF  'The two-loop five-particle amplitude in N = 8 supergravity'.
Preview
Content: Published Version
Filetype: PDF
Size: 565kB
View at publisher