The Standard Model is a remarkably successful but incomplete theory. Supersymmetry (SUSY) offers an elegant solution to the Standard Model's limitations, extending it to give each particle a heavy "superpartner" with different spin properties (an important quantum number distinguishing matter particles from force particles and the Higgs boson). For example, sleptons are the spin 0 superpartners of spin 1/2 electrons, muons and tau leptons, while charginos and neutralinos are the spin 1/2 counterparts of the spin 0 Higgs bosons (SUSY postulates a total of five Higgs bosons) and spin 1 gauge bosons.
* This article was originally published here