Gravi-Natural Higgs and Conformal New Physics
We study gauge hierarchy problem of the Standard Model (SM) not by introducing new physics at the electroweak scale but by utilizing gravitational frames, frames generated by conformal transformations, as a renormalization medium. The essence of the naturalization mechanism is that a particular conformal transformation with respect to the Higgs field completely decouples Higgs from matter fields so that the terms causing quadratic divergences become genuine benign. In this frame, we analyze stability, unitarity and renormalizability of the interactions, and construct the effective $SM$ theory at the electroweak scale by taking into account the conformal anomalies. We scrutinize certain salient features of the framework, and discuss h -> gamma gamma decay as an application. The proposed mechanism naturalizes not only the SM but also its extensions if they involve no new mass scales and exhibit strict conformal invariance. The new physics thus forms a conformal field theory (CFT), and can involve additional fermion generations, extra gauge groups as well as all kinds of SM singlets. Certain phenomena, for instance, CP-violating Higgs sector, Dark Matter and Inflation, can be modeled with less free parameters. Scalar and vector singlets can directly interact with the SM spectrum, and can be searched for in certain scattering processes such as the invisible decays of the Higgs boson.