Abstract

Rare decays of beauty hadrons provide some of the most sensitive probes of physics beyond the Standard Model, offering indirect access to energy scales orders of magnitude above the direct reach of the Large Hadron Collider. These processes occur via flavour-changing neutral currents, in which a beauty quark transforms into another down-type quark and two charged leptons. Forbidden at tree level in the Standard Model and therefore highly suppressed, such decays are particularly sensitive to contributions from heavy new particles.

Over the past decade and a half, the LHCb experiment has studied these processes with steadily increasing precision. Intriguingly, several measurements – particularly of branching fractions and angular observables – have shown tensions with Standard Model predictions. These anomalies may provide hints of new fundamental physics, although their interpretation is complicated by theoretical uncertainties associated with hadronic effects.

In this talk I will review recent progress in the study of rare beauty decays at LHCb and discuss how the rapidly growing dataset from the upgraded detector is transforming these modes into precision probes of new physics. I will highlight new measurements that can clarify the origin of the current anomalies and outline future opportunities for discovering physics beyond the Standard Model.