Inclusive semileptonic Λb decays in the Standard Model and beyond

Inclusive semileptonic decays of beauty baryons are studied using the heavy quark expansion to O1/mb3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \mathcal{O}\left(1/{m}_b^3\right) $$\end{document}, at leading order in αs. The case of a polarized decaying baryon is examined, with reference to Λb. An extension of the Standard Model effective Hamiltonian inducing b → Uℓν¯ℓ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ U\mathrm{\ell}{\overline{\nu}}_{\mathrm{\ell}} $$\end{document} transitions (U = u, c and ℓ = e, μ, τ) is considered, which comprises the full set of D=6 semileptonic operators with left-handed neutrinos. The effects of the new operators in several observables are described.