Probing the Green-Schwarz mechanism at the CERN Large Hadron Collider

We investigate the phenomenology of new Abelian gauge bosons, which we denote as X bosons, that suffer a mixed anomaly with the standard model, but are made self-consistent by the Green-Schwarz mechanism. A distinguishing aspect of the resulting effective theory is the decay of X bosons into standard model gauge bosons, X→ZZ, WW, γZ. We compute the production cross section of the X boson from vector boson fusion at the Large Hadron Collider. We study the pp→X→ZZ→4l signal, and analyze the prospects of discovery. We argue that such a discovery could indirectly probe high energies, even up to the string scale.