High-precision determination of the charm and bottom quark masses

Abstract

Quark masses are fundamental parameters of the Standard Model that play a keyrole in precision tests of the theory. They cannot be directly observed due to the confining nature of the strong interactions and can only be measured indirectly through observables that strongly depend on them and which can be computed with high precision in QCD. An example of these observables are moments of the inclusive $e^+e^-$ hadronic cross section. Their theoretical counterpart can be obtained through the use of the method of QCD sum rules. This framework can be adapted to pseudo-scalarcurrents as well, where experimental data are replaced by results from lattice QCD simulations. The agreement between these two methods is a non-trivial test of both the procedure and latticeQCD. However, so far, the charm quark mass determinations using the pseudo-scalar current suffer from large theoretical incertitudes. The main aim of this project is to improve the determination of the charm and bottom quark masses through the understanding of the origin of their uncertainties and the use of renormalization scheme variations to improve the convergence ofthe perturbative series. This would certainly lead to a much more reliable and precise extraction of these fundamental parameters. (AU)