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.