In particle physics, the chargino is a hypothetical particle which refers to the mass eigenstates of a charged superpartner, i.e. any new electrically charged fermion (with spin 1/2) predicted by supersymmetry. They are linear combinations of the charged wino and charged higgsinos. There are two charginos that are fermions and are electrically charged, which are typically labeled C͂ 1 (the lightest) and C͂ 2 (the heaviest), although sometimes χ χ ~ ~ 1 ± ± and χ χ ~ ~ 2 ± ± are also used to refer to charginos, when χ χ ~ ~ i 0 is used to refer to neutralinos. The heavier chargino can decay through the neutral Z boson to the lighter chargino. Both can decay through a charged W boson to a neutralino: