Speaker
Description
The Belle and Belle II experiments have collected a 1.1 ab$^{-1}$ sample of $e^+ e^-\to B\bar{B}$ collisions at a centre-of-mass energy corresponding to the $\Upsilon(4S)$ resonance. These data, with low particle multiplicity and constrained initial state kinematics, are an ideal environment to search for rare electroweak penguin $B$ decays and lepton-flavour violating decays to final states with missing energy from neutrinos. Results include those of the decay $B\to K^+\nu\bar{\nu}$ using an inclusive tagging technique. In addition, we present searches for the $SM$ processes $B\to K^{(*)}\tau^+\tau^-$. In addition, we present radiative B decay results. Finally, our search for the lepton-flavour violating decay $B^0\to K^{0}_{\rm S}\tau^+\ell^-$, where $\ell$ is an electron or muon, is described.
