Some theories predict the existence of additional elementary bosons and fermions that are not found in the Standard Model.
Supersymmetry predicts the existence of superpartners to particles in the Standard Model, none of which have been confirmed experimentally.
Forms a supermultiplet, together with the axino and the axion, in supersymmetric extensions of Peccei–Quinn theory.
Other superpartner categories include: The following hypothetical particles have been proposed to explain dark energy: The following categories are not unique or distinct: For example, either a WIMP or a WISP is also a FIP.
These hypothetical particles were claimed to be found or hypothesized to explain unusual experimental results.