Spin-2 fields and helicity
  By considering the irreducible representations of the Lorentz group, an analysis of the different spin-2 waves is presented. In particular, the question of the helicity is discussed. It is concluded that, although from the point of view of representation theory there are no compelling reasons to choose between spin-2 waves with helicity = + - 1 or helicity = + - 2, consistency arguments of the ensuing field theories favor waves with helicity = + - 1. 
H. I. Arcos, C. S. O. Mayor, G. Otalora and J. G. Pereira
gr-qc