Low-energy Effects of Lepton Flavour Universality Violation

Understand

The persisting anomalous data in semileptonic B-decays point towards New Physics models exhibiting large sources of Lepton Flavour Universality Violation.

• In this work we generalise previous studies by considering frameworks which include an enlarged set of semileptonic four-fermion operators invariant under the SM gauge group, with New Physics affecting mainly the third generation.
• We derive the low-energy effective Lagrangian including the leading electroweak corrections, mandatory to obtain reliable predictions.
• As a particularly interesting case, we analyse the scenario where the dominant New Physics effects are encoded in the Wilson coefficient C_9, as favoured by global fit analyses of b -> s data.