Standard Model predictions for lepton flavour universality ratios of inclusive semileptonic B decays

We present Standard Model predictions for lepton flavour universality ratios of inclusive B → X(c)ℓν¯ _ℓ. For the ℓ = μ, e, these ratios are very close to unity as expected. For the τ mode, we update the SM prediction for the branching ratio including power-corrections in the heavy-quark expansion up to 1/mb3. These inclusive ratios serve as an important cross-check of the exclusive B → D ^(*)ℓν¯ _ℓ modes, in which tensions exists between the predictions and measurements in those modes.