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, at leading order in alpha (s). The case of a polarized decaying baryon is examined, with reference to Lambda (b). An extension of the Standard Model effective Hamiltonian inducing b -> Ulnu l transitions (U = u, c and l = e, mu, tau) 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.