  All known elementary vector particles, the photon, Z, W and the gluons, are
described by the gauge theory. They belong to the real representation (1/2,1/2)
of the Lorentz group. On the other hand inequivalent representations (1,0) and
(0,1) also correspond to particles with spin 1. It is natural to suppose that,
along with the known vector particles, the new particles can exist. Evidence
for the existence of these particles in nature is the presence of the
axial-vector meson resonances with quantum numbers 1^{+-}. Other indications
for their existence are discussed. The signatures of their contributions into
different physical processes are presented.
