Novel cluster-algebraic letters for six- and five-point QCD processes

Georgios Papathanasiou (UOA)

Mar 18. 2026, 10:30 — 11:30

By breaking dual conformal invariance, we transform cluster-algebraic predictions for the alphabet of 9-point amplitudes in N=4 super Yang-Mills theory to analogous predictions for 5- and 6-point processes in QCD. We start by obtaining, for the first time, candidate letters for 6-point processes with one massive external leg, and discover that they surprisingly also contain nested square roots. We confirm that our results essentially contain the alphabet of all 1-loop integrals with these kinematics, and in their massless limit also the recently computed alphabet of finite, planar 2-loop amplitudes for 6-point massless QCD processes. In the latter case, we additionally find 162 letters that may appear at higher loops. We similarly produce candidate letters for 5-point 2-mass processes, whose comparison with the literature reveals a nontrivial overlap that also includes new letters.

Further Information
Venue:
ESI Boltzmann Lecture Hall
Associated Event:
Amplitudes and Algebraic Geometry (Thematic Programme)
Organizer(s):
Daniele Agostini (U Tübingen)
Lara Bossinger (UNAM, Oaxaca)
Ruth Britto (Trinity College, Dublin)
Johannes Henn (MPP, Munich)
Jianrong Li (U of Vienna)
Anna-Laura Sattelberger (MPI MIS, Leipzig)
Oliver Schlotterer (Uppsala U)