We present a determination of the strong coupling constant in the MS-bar scheme at the Z-mass scale, using low energy quantities, namely pion/kaon decay constants and masses, as experimental input. The computation employs two different massless finite volume renormalization schemes to non-perturbatively trace the scale dependence of the respective running couplings from a scale of about 200 MeV ... More

Models for what may lie behind the Standard Model often require non-perturbative calculations in strongly coupled field theory. This creates opportunities for lattice methods, to obtain quantities of phenomenological interest as well as to address fundamental dynamical questions. I will survey recent work in this area.

I emphasize the importance of an accurate determination of the strong coupling constant for precision and discovery physics at the LHC. I review critically the main sources of experimental information on alphas, and their experimental and theoretical limitations and potential. I specifically discuss issues related to selecting possibly more reliable measurements, to discarding apparent outliers, ... More