The 17th International Workshop on Tau Lepton Physics (TAU2023)

Session

Wednesday before lunch

6 Dec 2023, 10:50

Conveners

Wednesday before lunch: QCD

• Zbigniew Andrzej Was (Polish Academy of Sciences)

38. The Euclidean Adler function and its interplay with low-energy data and $\alpha_s$

Antonio Rodriguez Sanchez

06/12/2023, 10:50

Plenary Presentation

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...

9. New Physics in Hadronic Tau Decays

David Díaz Calderón

06/12/2023, 11:10

Plenary Presentation

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...

81. Renormalon subtraction in hadronic tau decays

Dr Hiromasa Takaura

06/12/2023, 11:30

Plenary Presentation

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...

30. Update on alpha_s from hadronic tau decays

Maarten Golterman

06/12/2023, 11:50

Plenary Presentation

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.

44. Difference between fixed-order and contour-improved perturbation theory

Santi Peris

06/12/2023, 12:10

Plenary Presentation

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...