Neutral $B$ meson mixing and $B$ meson lifetimes are theory-side parametrised in terms of $\Delta B=2$ and 0 four-quark operators which can be determined by calculating weak decay matrix elements using lattice QCD.
While calculations of $\Delta B=2$ mixing matrix elements are standard, matrix elements with $\Delta B=0$ for extracting lifetimes suffer from complications in standard...
The baryon asymmetry of the universe requires sources of CP-violation beyond those predicted by the SM. At the same time, experimental constraints on the neutron electric dipole moment leave a large window for CP-violating contributions beyond the SM. Such contributions can be described by CP-violating effective interactions at hadronic energies in QCD. Because of confinement, these...
Non-perturbative static force measurements on the lattice can be used to extract the QCD scale $\Lambda_\mathrm{QCD}$ by comparison to perturbative results. We measure the static force on the lattice directly. The corresponding observable consists of a Wilson loop with a discretized $E$-field insertion in one of the temporal Wilson lines. This causes discretization effects, which have to be...
We have applied the gradient flow to an SU(4) gauge theory with two sets of fermions in separate gauge representations. We have a clean result for the beta function of the theory up to and beyond an infrared fixed point. Using the fermion GF we have obtained anomalous dimensions for mesonic operators and for the chimera operators that are needed for top quark mixing. We were able to reach...
A lattice implementation is described for the beta-function defined over infinite Euclidean space-time in the continuum. It is based on scale changes of the renormalized gauge coupling generated by infinitesimal or finite steps on the gradient flow. Harlander and Neumann calculated in this scheme the three-loop approximation to the continuum beta-function. Our goal is the nonperturbative...