THE PHOTOMAGNETON AND PHOTON HELICITY

It is shown that the real and physical Pauli-Lubansky pseudo-four-vect or (V-mu) dual to the electromagnetic four-tenser in free space is pro portional to photon helicity. Therefore V-mu is rigorously non-zero, s howing that the photomagneton ($) over cap B-(3) is rigorously non-zer o in the theory of special relativity. In the conventional approach to free space electromagnetism, the photomagneton is at best not conside red (because it is not a transverse wave), and at worst asserted to be zero. Physical effects are expected from the interaction of ($) over cap B-(3) with matter. The vector V-mu contains the expectation value (B-z) of ($) over cap B-(3) as it, space-like and time-like component, i.e. V-mu = epsilon(0)c(0,0,B-z, iB(z)). The imaginary pseudo-four-ve ctor W-mu = - i epsilon(0)(0,0, E(z),iE(z)) is dual to V-mu in free sp ace, but its components are unphysical because they are imaginary. The refore B, in free space is dual to an imaginary and unphysical longitu dinal electric field.