Helicity, spin, and infra-zilch of light: A Lorentz covariant formulation

In this paper, a novel conserved Lorentz covariant tensor, termed the helicity is introduced in Maxwell theory. The conservation of tensor expresses laws contained array, by Cameron et al., including helicity, spin, and spin-flux or infra-zilch. covariance contrast to previous formulations hierarchy laws, which required non-Lorentz transverse gauge. shown arise as Noether current for variational symmetry duality-symmetric Lagrangian This transformation generalizes duality includes underlying spin part angular momentum.