In particle physics, a spinor field of order 2s describes a particle of spin s, where s is an integer or half-integer. Therefore, a spinor of order 4s contains as much information as a tensor of order 2s. As a result of this, particles of integer spin (bosons) can be described equally well by tensor fields or spinor fields, whereas particles of half-integer spin (fermions) can be described only by spinor fields. Spinor fields describing particles of zero rest mass satisfy the zero rest mass equation.

spinor | twistor | zero rest mass equation