Background studies of B → K^(*) ν anti ν decays at Belle II

The B → K^(*) ν anti ν decays provide some of the cleanest experimentally measurable instances of the flavour changing neutral current process b → sν anti ν, which presents an excellent opportunity to investigate physics beyond the standard model. The missing energies of the two neutrinos make the measurement experimentally challenging and require the full reconstruction of the spectator B meson in e⁺e^- → Υ(4S) → B anti B events. Observation of the B → K^(*) ν anti ν decays will only become possible with the large data set that will be collected at the upgraded Belle II detector at the SuperKEKB accelerator in Tsukuba, Japan. A challenge of this decay analysis will be the understanding and suppression of the backgrounds. New techniques will be required to identify and simulate background events in sufficient volumes for statistical analysis.