Enhancement of h→γγh→γγ via spin-0 and spin-1/2 charged unparticle loops

We calculate the spin-0 and spin-1/2 charged unparticle loop contributions to the Higgs diphoton decay within an unparticle gauge model and show that they can significantly enhance or suppress SM predictions for the same. In the SM limits of scalar and fermion conformal dimensions, dUs→1dUs→1 and dUf→3/2dUf→3/2 respectively, our results exactly reproduce the contributions of the spin-0 and spin-1/2 particle cases. Furthermore the decoupling from the Higgs boson occurs only for the spin-0 case in the critical limit dUs→2dUs→2. Using the recent ATLAS data which reported an excess of diphoton decay rate of SM-like Higgs boson around 125 GeV, and taking into account the vacuum stability and perturbativity conditions, the parameters of the gauge unparticle model are constrained.