How the Little Group Constrains Massless Field Representations in Higher   Even Dimensions
  Assuming trivial action of Euclidean translations of the little group, we derive a simple correspondence between massless field representations transforming under the full generalized even dimensional Lorentz group, and highest weight states of the relevant little group. This yields a connection between `helicity' and `chirality' in all dimensions, and highlights the special nature of the restricted representations under `gauge' transformations. 
Vineer Bhansali