Charm Mass Determination from QCD Charmonium Sum Rules at Order alpha_s^3

por Vicent Mateu (MIT Boston and IFIC Valencia)

viernes 21 ene. 2011 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

We determine the MS-bar charm quark mass from a charmonium QCD sum rules analysis. On the theoretical side we use input from perturbation theory at alpha_s^3. Improvements with respect to previous analyses include (1) an account of all available e+ e- hadronic cross section data and (2) an appropriate estimate of perturbative uncertainties. Using a method to combine different hadronic cross section data sets we demonstrate that using all available experimental data up to c.m. energies of 10.5 GeV allows for determinations of experimental moments and their correlations with small errors and that there is no need to rely on theoretical input above the charmonium resonances. We also show that the good convergence properties of the perturbative series for the theoretical sum rule moments need to be considered with some care and that a wider range of scheme variations has to be applied to obtain a more appropriate estimate of the perturbative uncertainty.