Hi

I am supposed to write a 5000 word essay on a Weinberg-Witten Theorem which forbids the existence of massless particles with helicity j > 1

in any theory with a Lorentz-covariant energy-momentum tensor and how both graviton and gluon evade the assumptions of this proof due to gauge symmetry. I was wondering whether anybody could point out some references which might be useful. Thanks in advance

I never fully undersood it, but basically it is because higher spin particles will not couple to gravity in a consistent way.

 

David Bailin gave a short talk on this at Sussex as part of the theory groups informal seminars. There is a link to the ps notes here