Neutralino

In particle physics, the neutralino is a hypothetical particle and part of the doubling of the menagerie of particles predicted by supersymmetric theories.

Since the superpartners of the Z boson (zino), the photon (photino) and the neutral higgs (higgsino) have the same quantum numbers, they mix to form eigenstates of the mass operator, called neutralinos. The lightest neutralino is thought to be stable. Virtually undetectable, it participates only in weak and gravitational interactions. Of the weakly-interacting massive particles (WIMPs) under consideration, the lightest neutralino at 30–5000 proton masses, is the leading candidate for cold dark matter. The exact behaviour of this particle depends on, which of it constituent dominates, the higgsino, photino or zino.