Short- vs long-distance dynamics in $b \to s \ell \ell$ decays and connection to other flavor anomalies

by Arianna Tinari

Thursday 27 Nov 2025, 14:00 → 15:00 Europe/London

Rare flavor-changing processes offer very sensitive probes of physics beyond the Standard Model. The persistent discrepancies between theory and experiment in $b \to s \ell \ell$ decays, both in branching ratios and angular observables, can be explained by a 20-25% shift in the Wilson coefficient $C_9$, potentially signaling new short-distance physics or underestimated long-distance effects from non-local hadronic contributions. We discuss the non-local effects associated with rescattering through $D^{(*)} D_s^{(*)}$ intermediate states. $b \to s \ell\ell$ anomalies, together with other small deviations in flavor observables, can be simultaneously explained in models of new physics at the TeV scale mostly coupled to third-generation fermions, featuring an approximate $U(2)^5$ flavor symmetry acting on the light families. We discuss the constraints on these models from current data.