12–14 Feb 2025
University of Zürich
Europe/Zurich timezone

Gradient-flow renormalon subtraction and the hadronic tau decay series

14 Feb 2025, 13:30
30m
Y36-K08 (University of Zürich)

Y36-K08

University of Zürich

Winterthurerstrasse 190 8057 Zürich Switzerland
Invited talk Session 11

Speaker

M Beneke

Description

The inconsistency between the fixed-order (FO) and contour-improved (CI) representation of the QCD corrections to the inclusive hadronic tau decay width limits the precision to which the strong coupling can be determined from this process. It has been shown that subtracting the infrared renormalon divergence related to the gluon condensate resolves the discrepancy. We employ the gradient flow to define gauge-invariant regularized operators and to use the corresponding condensates in the operator product expansion. The associated rearrangement of the perturbative series results in automatic renormalon subtraction without the need to determine explicitly the Stokes constants that normalize the divergent asymptotic series. Applying this method to the gluon condensate, we find that the CI series is modified and now agrees with the (unmodified) FO series.

Author

M Beneke

Co-author

Hiromasa Takaura

Presentation materials