Searches for Invisible New Particles at Belle II

Belle II has unique sensitivity for a broad class of models postulating the existence of dark matter particles with masses in the MeV–GeV range. We present recent world-leading results from Belle II searches for several non-SM particles. These include production of $$Z^{\prime}$$ bosons, axion-like particles, and dark scalars in association with two muons in $$e^{+}e^{-}$$ collisions; long-lived (pseudo)scalars produced in decays of B-mesons; and invisible particles produced in decays of $$\tau$$ leptons.