Supersymmetry

There are more abstract symmetries in physics, and a prominent example of this is called supersymmetry. One consequence of this symmetry, assuming it is borne out in nature, is that every particle has a shadow particle called its superpartner. The superpartners would have identical properties to the original particle, except for having different spins. The selectron, for example, is the inferred superpartner of the electron. It has the same mass and charge as the electron but, unlike the electron, it has no spin.