Conveners
Wednesday before lunch: QCD
- Zbigniew Andrzej Was (Polish Academy of Sciences)
Perturbative QCD gives a precise description of the Euclidean Adler function at large momenta. A comprehensive study of the perturbative approach is presented for momenta of the order of the tau mass, including the different expansions at all known orders. We then compare to the corresponding Adler functions obtained from experimental data and lattice simulations and comment on the...
This talk is based on the main results of the published article JHEP 04 (2022) 152. Model independent bounds on new physics are obtained using hadronic tau decays as observables. To do this, we determine the dependence of several inclusive and exclusive tau observables on the Wilson coefficients of the low-energy effective theory describing charged-current interactions between light...
The hadronic tau decay width is regarded as an important observable from which the strong coupling can be extracted precisely. However, the inconsistency in the calculations between two perturbative methods, known as FOPT and CIPT, had been a long standing problem until recently. We propose a new method to remove the renormalon divergence, which has turned out to cause the problem, by...
We discuss recent work on the methodology for determining
the strong coupling, alpha_s, from hadronic tau decays. In
particular, we address a number of concerns that have been
raised with regard to the method we employ, showing that
all of these concerns are unfounded.
Using standard mathematical methods for asymptotic series and the large-β0
approximation, we define a Minimum Distance between the Fixed-Order pertur-
bative series and the Contour-Improved perturbative series in the strong coupling
α_s for finite-energy sum rules as applied to hadronic τ decays. This distance is
similar, but not identical, to the Asymptotic Separation of Hoang and...
