Speaker
Matteo Fael
(CERN)
Description
We present the QCD corrections of order $\alpha_s^3$ to the decay rate of $b \to u l \bar \nu_l$, originating from diagrams with closed fermion loops and neglecting the mass of the up quark. Our calculation relies on integration-by-parts reduction of Feynman integrals with one propagator raised to a symbolic power in Kira.
The five-loop master integrals are then evaluated with AMFlow numerically, together with an ad hoc interface to Kira. This allows us to obtain results for the fermionic contributions to the total semileptonic rate with an accuracy of more than thirty digits
Author
Matteo Fael
(CERN)
Co-author
Johann Usovitsch
(CERN)
