Enhanced color gauge invariance and a new di-photon state at the LHC
  We propose to interpret the possible resonance seen in di-photons at the LHC at 750 Gev as a bound state of a new pair of heavy gluons associated with an enhanced color gauge invariance. These have a conservation law which enforces their production and decay in pairs and hence requires that the leading coupling to quarks is quadratically through a dimension 5 operator. One way to realize these hypotheses is if the SU(3) color gauge invariance is enhanced to SL(3, C), while at the same time promoting the internal metric, which picks out what is a unitary transformation, to a dynamical degree of freedom. This theory was first proposed by Cahill[3], Dell[4], Kim and Zee[5], and Julia and Luciani[6]. The dynamical internal metric spontaneously breaks SL(3,C) to SU(3) giving a mass to the vector bosons associated with the generators in SL(3,C)/SU(3). The coupling to the internal metric also ensures that the energy is bounded from below. The new state is produced by gluon fusion and decays to a pair of photons via a direct coupling to a new set of vector quarks allowed by the symmetries. 
Stephon Alexander, Lee Smolin
hep-ph