Charge radius the composite particle must be modeled as a sphere of negative rather than positive electric charge for the interpretation of electron scattering experiments. In these cases, the square of the charge radius of the particle is defined to be negative, with the same absolute value with units of length squared equal to the positive squared charge radius that it would have had if it was identical in all other respects but each quark in the particle had the opposite electric charge (with the charge radius itself having a value that is an imaginary number with units of length). It is
Charge (physics) a particular representation of that symmetry; the charge quantum number is then the weight of the representation. Various charge quantum numbers have been introduced by theories of particle physics. These include the charges of the Standard Model: Charges of approximate symmetries: Hypothetical charges of extensions to the Standard Model: In supersymmetry: In conformal field theory: In gravitation: In the formalism of particle theories, charge-like quantum numbers can sometimes be inverted by means of a charge conjugation operator called C. Charge conjugation simply means that a given symmetry group occurs in two inequivalent (but still isomorphic) group representations. It is usually