Study of $B^{+}\to {\mu }^{+}{\nu }_{\mu }$ decays at Belle and Belle II

Belle, Belle II Collaborations, : +412

We report a measurement of the branching fraction for the leptonic decay $B^{+}\to {\mu }^{+}{\nu }_{\mu }$. This work presents the first $B^{+}\to {\mu }^{+}{\nu }_{\mu }$ result using Belle~II data, an updated Belle me…