Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

Three-loop four-particle QCD amplitudes

Jul 8, 2022, 9:30 AM
Room 7 (Gialla)

Room 7 (Gialla)

Parallel Talk Formal Theory Formal Theory


Piotr Bargiela (University of Oxford)


Scattering amplitudes are the fundamental building blocks of collider observables. Comparing high precision measurements to theory predictions requires computing them to high perturbative order. The growth in the number of loops significantly increases the complexity of the problem. Using novel mathematical methods allowed to compute QCD corrections to four-point massless processes at state-of-the-art three-loop order. We will describe these modern tools and show their example application to recently published diphoton production in gluon fusion channel. This particular process is a leading background for Higgs production in the discovery channel. The analytic amplitude which we have computed can be used to derive fully differential NNLO hadronic cross section, since the subtraction schemes are already available. Because of the interference with the signal, it can put stronger bounds on the Higgs width.

In-person participation Yes

Primary authors

Piotr Bargiela (University of Oxford) Giulio Gambuti (Istituto Nazionale di Fisica Nucleare)


Presentation materials