Speaker
Description
We present an efficient algorithm for constructing all the covariant tensor
currents of massless particles of arbitrary spins in the covariant formulation. This
algorithm enables us to extract directly the field theoretical current structures from
their three-point vertices and to find clearly the in-out matrix elements in the
lightlike limit. We revisit the closely-related two restrictions on massless particles
called the Landau-Yang (LY) and Weinberg-Witten (WW) theorems in terms of
arbitrary spins. We find the covariance conditions on form factors leading to the
corresponding tensor currents being covariant and verify that the continuity
assumption of matrix elements taken for obtaining the WW theorem in the original
paper is correct at least in quantum field theory involving conventional fields.
