Probing New Physics with heavy hadron decays

TL;DR

This paper investigates heavy hadron decays, especially polarized beauty baryons, to identify observables sensitive to new physics beyond the Standard Model, using a model-independent effective Hamiltonian approach.

Contribution

It extends the analysis of semileptonic decays to include all D=6 operators with left-handed neutrinos, providing new observables for future experimental tests.

Findings

Identified promising observables for new physics searches.

Extended the theoretical framework to include all relevant semileptonic operators.

Provided predictions applicable to future collider experiments like FCC-e.

Abstract

The increasing number of flavour anomalies calls for the investigation of new processes where tensions similar to the observed ones could emerge. Observables sensitive to physics beyond the Standard Model need to be identified. We discuss the inclusive semileptonic decays of polarized beauty baryons, computed through the heavy quark expansion at ${\cal O}(1/m_b^3)$ and at the leading order in $\alpha_s$. We account for New Physics interactions in a model-independent way, extending the Standard Model $b \to U \ell {\bar \nu}_ \ell$ low energy Hamiltonian (with $U=u,\,c$ and $\ell=e,\,\mu,\,\tau$) with the inclusion of the full set of D=6 semileptonic operators with left-handed neutrinos. We identify a set of promising observables, the study of which can be included in the physics programmes of future facilities, such as FCC-e.