U-spin Sum Rules: From Amplitudes to Observables. Bonus if time allows: some news on b->s tau tau measurements

by Margarita Gavrilova

Wednesday 29 Oct 2025, 11:30 → 12:30 Europe/Zurich

4/2-037 - TH meeting room (CERN)

Abstract: In the first part of my talk, I will review our recent results on the systematics of U-spin amplitude sum rules. Our study revealed a rich mathematical structure underlying the sum rules. Building on this, we developed an algorithm that allows the derivation of all U-spin amplitude sum rules to any order in symmetry breaking and for any system of hadron decays related by U-spin. The procedure requires no explicit calculations and allows for a simple diagrammatic interpretation. 

However, I’m most excited to share our newest results that extend this to sum rules between decay rates. Strikingly, much of the underlying structure persists at the level of rates, even when phase space is taken into account. With the systematic framework in hand, higher-order rate sum rules in concrete hadron decay families become apparent immediately, and I’ll show several new examples.

I am looking forward to a discussion of possible phenomenological applications of these results.