Mathematically it may look as though all of the fields are vector-valued (in addition to being operator-valued), since they all have several components, can be multiplied by matrices, etc., but physicists assign a more specific physical meaning to the word: a vector is something that transforms like a four-vector under Lorentz transformations, and a scalar is something that is invariant under Lorentz transformations. The , and fields are all vectors in this sense, so the corresponding particles are said to be vector bosons. The Higgs field is a scalar field.