New results on $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$ using inclusive and exclusive $B$ decays from the Belle experiment

We present two recent measurements of semileptonic B decays at Belle, offering valuable insights into the determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$. These analyses use the full Belle dataset, comprising $772\times {10}^6$ $B\bar{B}$ pairs collected at the $\mathrm{{\rm Y}}(4S)$ resonance. With an innovative strategy, the inclusive $B\to X_u\mathrm{\ell }\nu$ and exclusive $B\to \pi \mathrm{\ell }\nu$ decays are simultaneously analyzed for the first time, and the $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$ ratio is extracted as $\mathrm{\mid }{V}_{ub}^{\mathrm{e}\mathrm{x}\mathrm{c}\mathrm{l}\mathrm{.}}\mathrm{\mid }\mathrm{/}\mathrm{\mid }{V}_{ub}^{\mathrm{i}\mathrm{n}\mathrm{c}\mathrm{l}\mathrm{.}}\mathrm{\mid }=0.97\pm 0.12$. Furthermore, we provide preliminary results for the inclusive branching fractions ratio of $B\to X_u\mathrm{\ell }\nu$ and $B\to X_c\mathrm{\ell }\nu$ decays, accompanied by additional interpretations aimed at deriving the inclusive $\mathrm{\mid }{V}_{ub}\mathrm{\mid }\mathrm{/}\mathrm{\mid }{V}_{cb}\mathrm{\mid }$ ratio.