Thursday, April 16, 2025, 16:00
WHGA/001
Jordy de Vries, University of Amsterdam/Nikhef
Abstract:
All good things come in threes. The Standard Model takes this to heart and
contains three generations of quarks. The weak interaction can transmute one
generation into another. Each such transition is governed by a quark mixing
angle, and while the Standard Model does not predict their values, it does
insist that they fit together in clean unitarity relations. The most precise
extractions of the up‑quark sector mixing angles now appear to violate these
relations: the so‑called Cabibbo angle anomaly. Whether this is a crack in the
Standard Model or a mirror held up to our theoretical machinery is not yet
clear. The optimist sees a hint of new physics; the pessimist blames the
difficult radiative corrections in meson, nucleon, and nuclear beta decays.
In this talk I will play both sides and discuss how beyond‑the‑Standard‑Model
scenarios could explain the anomaly, and how improved control of radiative
corrections reshapes the picture.