Photon mass and the fieldB (3)

The connection between finite photon mass and the fieldB⁽³⁾ is developed with reference to special relativity in the vacuum. The existence of the physical and longitudinal fieldB⁽³⁾ implies that there are three degrees of polarization associated with the photon, which cannot therefore be a massless boson. The fieldB⁽³⁾ can be observed experimentally through the magnetization of a plasma with microwave pulses, and this experiment serves to demonstrate unequivocally the existence of photon mass.