Speaker
Vsevolod Chestnov
(University of Oxford)
Description
In this talk I will present the numerical calculation of two-loop QCD amplitude
for the associated production of a top-anti-top pair and a $W$ boson in the
leading-colour approximation.
The amplitude is expressed as linear combinations of special transcendental
functions with rational function coefficients, evaluated using differential
equations and finite-field techniques, respectively. I will highlight the main
challenges of the computation, which arise from the analytic structure of the
differential equations and the high dimensionality of the phase space.
We evaluate the finite two-loop remainder on a phase-space grid, and use it to
obtain the NNLO QCD corrections to the inclusive cross section for $t\bar{t}W$
production at the LHC.
Author
Vsevolod Chestnov
(University of Oxford)