Prospects in flavour physics at the FCC

The sample of 6×10^12 Z decays that will be produced by FCC-ee offers immense opportunities for
flavour physics. The low background environment, and high acceptance and reconstruction efficiencies
of the detectors will allow this dataset to be fully exploited for a wide range of studies in the beauty,
charm and tau sectors. In many cases, it is expected that these measurements will be world-leading in
precision, and thereby be powerful in probing for the effects of New Physics. Interesting possibilities also
exist for the measurement of the magnitude of CKM elements from W-boson and top decays. Discussion
and numerical estimates are provided for the prospects of FCC-ee in a set of benchmark measurements,
as requested by the Physics Preparatory Group of the European Strategy for Particle Physics Update
2025. Additional discussion is included on some other studies of interest. Finally, brief consideration is
given to the prospects for flavour-physics studies at FCC-hh.

Contribution to the European Strategy for Particle Physics Update (2025-2026)