Measurement of Branching Fraction and Longitudinal Polarization in $B^0\to {\rho }^{+}{\rho }^{-}$ Decays at Belle II

Belle II Collaboration, F. Abudinén, I. Adachi +584

We present a measurement of the branching fraction and longitudinal polarization of $B^0\to {\rho }^{+}{\rho }^{-}$ decays. SuperKEKB electron-positron collision data corresponding to 189~fb$^{-…