Precise determination of the C quark mass

Abstract

In the absence of direct observation of Beyond Standard Model physicsat the LHC, precise tests of the theory require increasing precision.In many calculations, the limiting factor is the precision of thefundamental parameters of QCD, namely the strong coupling and quarkmasses. In the case of the c quark mass, a promising method for itsextraction is the use of sum rules for the pseudoscalar correlator,where the theoretical prediction in pertubative QCD is compared tolattice QCD data, which have increased a lot in precision lately. Atthe moment, this determination is limited by the theoreticalprediction, since the pertubative series of the pseudoscalarcorrelator, known up to third order in $\alpha_s$, is rather unstable.The main goal of this research project is to understand the origin ofthis instability in the pertubative series in terms of thesingularities known as renormalons. Thereby, one can find rigorousmethods in order to circumvent this instability and be able to fullyuse lattice QCD data for a precise determination of $m_c$ andtherefore contribute to precise tests of the Standard Model. (AU)