Non-power functional expansions for QCD observables at low energies

by Dmitry Shirkov (JINR, Dubna)

Thursday 10 Mar 2005, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

Presentation of the progress made during the last few years in further developing the ghost-free Analytic Approach to low-energy QCD. It is formulated as a closed 'Analytic Perturbation Theory' (APT) algorithm. Its most spectacular feature, besides the absence of ghosts, is non-power functional expansions for QCD observables. Expansion functions are oscillating in the low-energy domain, where the QCD coupling is not weak. This, in turn, suppresses the influence of higher-loop contributions, diminishes the scheme dependence and improves the convergence properties of expansion for observables. We review recent applications of the APT algorithm, discuss its convergence properties and outline some further possible development.