Semileptonic B decays from Belle and Belle II

This report summarizes recent measurements of the CKM matrix elements |Vcb|, |Vub|, and lepton-flavor universality tests in semileptonic B decays from the Belle and Belle~II experiments. The decay branching factions R(D*) and $R(X)$ are measured with the Belle~II early dataset and the results are found to be consistent with the Standard Model predictions. From a simultaneous measurement of untagged B⁰ → π⁻ ⁺ ν and B⁺ → ρ⁰ ⁺ ν, the |Vub| value is determined incorporating external theoretical constraints on the decay form factors. The first measurement of the full angular coefficients for B → D^* ν decays at Belle provides comprehensive information for determining the decay form factors and |Vcb|. This presentation also includes measurements of the ratios |Vub|ᵉˣᶜˡ/|Vub|ⁱⁿᶜˡ and |Vub|ⁱⁿᶜˡ/|Vcb|ⁱⁿᶜˡ.