We study inclusive semileptonic \(\overline{B}\to {X }_{c}{\ell}\overline{\nu }\) decays (ℓ = e, μ) in the presence of generic physics Beyond the Standard Model (BSM) that is heavy compared to the b-quark mass. Its effect is encoded in the Wilson coefficients of dimension-six operators of the Weak Effective Theory (WET). We compute the resulting BSM contributions to the experimentally measured kinematic moments and the total decay rate through order \(\mathcal{O}\left({\Lambda}_{\text{QCD}}^{3}/{m}_{b}^{3}\right)\) in the Heavy Quark Expansion, as well as the \(\mathcal{O}\left({\alpha }_{s}\right)\) corrections for the right-handed vector current. We then perform fits to the full set of available inclusive measurements in several single-mediator scenarios and in the full WET basis. We find qualitatively new bounds in several of these scenarios, complementary to and competitive with constraints from exclusive decays.
