Topical Seminar: The CIPT-FOPT discrepancy for hadronic tau decays

por Andre Hoang (University of Vienna)

viernes 30 jun. 2023 10:00 → 11:59 Europe/Madrid

1001-Primera-1-1-1 - Paterna. Seminario (Universe)

The discrepancy of the contour-improved (CIPT) and fixed-order perturbative (FOPT) expansion of moments for the hadronic tau decay invariant mass distribution has affected the uncertainty of strong coupling measurements for many years. Recently, the origin of the discrepancy has been finally understood to be related to a sensitivity to infrared momenta of the CIPT method that is not consistent with the operator product expansion of QCD.The discrepancy can be reconciled by switching to a renormalon-free scheme for the dimension-4 gluon condensate matrix element, which renders CIPT to become compatible with FOPT. This will lead to a reduction of the uncertainties in strong coupling determinations. In the talk review the results I have obtained in a number of recent publications on this topic, elaborating on mathematical as well as conceptual aspects.

A ZOOM connection is available here:

https://dicv-csic-es.zoom.us/j/84735465044?pwd=
MVltSWJ6L3ZGZSs2UitIYWM5c1dZdz09

A recording is found here ( password FrVx8*9$ ):

https://dicv-csic-es.zoom.us/rec/share/mcKnRAXNQhluR8oaErGbYWVtZgxizvde-61WUshva3o1bANzDUEJamIimZt2EMs.hxV5LDnn4ZG03Fov

Hoang-Tau-CIPT-FOPT-Valencia-2023.pdf