Dr. Diogo Boito (Technische Universitaet Muenchen --- TUM)
I present a discussion of recent developments in the QCD description of hadronic tau decays with emphasis in the perturbative contribution. The perturbative series is the main ingredient in the extraction of the strong coupling (alpha_s) from these decays. The ambiguity due to the different prescriptions regarding the renormalization group improvement of the series is studied under different assumptions for the large-order corrections. Our results show that some of the hadronic spectral function moments employed in alpha_s determinations have poor perturbative behaviour and should be avoided. Exploiting this information we develop the optimal theoretical framework for precise alpha_s extractions from the 2014 update of the ALEPH data. Some preliminary results of our 2014 analysis will be discussed.