Contributor info: Dr Fabian Lange

Matteo Fael, Fabian Lange, Kay Schönwald, Matthias Steinhauser

SciPost Phys. Proc. 7, 041 (2022) · published 22 June 2022 | Toggle abstract · pdf

We discuss a practical approach to compute master integrals entering physical quantities which depend on one parameter. As an example we consider four-loop QCD corrections to the relation between a heavy quark mass defined in the $\overline{\rm MS}$ and on-shell scheme in the presence of a second heavy quark.

Fabian Lange

SciPost Phys. Proc. 7, 033 (2022) · published 21 June 2022 | Toggle abstract · pdf

Over the last decade the gradient flow formalism became an important tool for lattice simulations of Quantum Chromodynamics. It offers remarkable renormalization properties which pave the way for cross-fertilization between perturbative and lattice calculations. In this contribution we discuss the perturbative approach. As first application we compute vacuum expectation values of flowed operators which could help to extract parameters like the strong coupling constant from lattice simulations. Afterwards, we apply the flowed operator product expansion to the time-ordered product of two currents which could be employed for an alternative first-principle evaluation of vacuum polarization functions on the lattice.

Fabian Lange, Philipp Maierhöfer, Johann Usovitsch

SciPost Phys. Proc. 7, 017 (2022) · published 21 June 2022 | Toggle abstract · pdf

Last year we released version 2.0 of the Feynman integral reduction program Kira. In this contribution we first report on changes and new features since then and, secondly, on new features for upcoming releases.