High-precision computations on fine lattices

Lattice Quantum Chromodynamics (LQCD) is the only known ab-initio approach to compute observables in the non-perturbative regime of the strong interactions of particles and fields. The theory of strong interactions is solved numerically in finite volumes on an Euclidean space-time grid. The framework of LQCD has systematically improvable statistic and systematic uncertainties.

It provides highly relevant theoretical input for high-energy and nuclear physics.

The precision of LQCD computations has significantly improved in the last years thanks to algorithmic advancements.This project aims to further improve the precision of phenomenologically important observables.

The improvement will be achieved by the development and application of noise reduction techniques to reduce statistical uncertainties at computationally challenging, very fine resolutions of LQCD simulations.The focus of this project will be on the improved determination of the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon.

Precise theoretical predictions of this observable are of utmost importance in the search for physics beyond the Standard Model of particles as the uncertainties of the experimental results will significantly decrease in the upcoming years.

The computation of the hadronic vacuum polarization in the framework of LQCD suffers from an exponentially enhanced increase of the noise-to-signal ratio in the low energy region.

Furthermore, the precision of state-of-the-art determinations is bounded by systematic uncertainties due to the presence of the finite grid.

Both uncertainties will be addressed and reduced in this work.Furthermore, the approach will be tested in the computation of B-physics observables that are needed to investigate currently observed anomalies in the heavy quark flavor sector of the Standard Model.