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DOE OSTI · 2870308

All-order splits and multi-soft limits for particle and string amplitudes

Arkani-Hamed, Nima [Institute for Advanced Study, Princeton, NJ (United States)] (ORCID:0009000527503999)·Figueiredo, Carolina [Princeton University, NJ (United States)] (ORCID:0000000273989089)
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Abstract

The most important aspects of scattering amplitudes have long been thought to be associated with their poles. But recently a very different sort of “split” factorizations for a wide range of particle and string tree amplitudes have been discovered away from poles. In this paper, we give a simple, conceptual origin for these splits arising from natural properties of the binary geometry of the curve integral formulation for scattering amplitudes for Tr(Φ 3 ) theory. The most natural way of “joining” smaller surfaces to build larger ones directly produces a choice of kinematics for which higher amplitudes factor into lower ones. This gives a generalization of splits to all orders in the topological expansion. These splits allow us to access and compute loop-integrated multi-soft limits for particle and string amplitudes, at all loop orders. This includes split factorizations and multisoft limits for pion and gluon amplitudes, that are related to Tr(Φ 3 ) theory by a simple kinematical shift.

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Arkani-Hamed, Nima [Institute for Advanced Study, Princeton, NJ (United States)] (ORCID:0009000527503999), Figueiredo, Carolina [Princeton University, NJ (United States)] (ORCID:0000000273989089). 2025-10-09. All-order splits and multi-soft limits for particle and string amplitudes. https://doi.org/10.1007/jhep10(2025)077

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