A Higgs-Free Model for Fundamental Interactions and its Implications

A model for strong, electroweak and gravitational interactions based on the local symmetry group $G=SU(3)\times SU(2)_{L}\times U(1)\times C$ where $C$ is the local conformal symmetry group is proposed. The natural minimal $G$-invariant form of total lagrangian is postulated. It contains all Standard Model fields and the gravitational interaction, however the Higgs mass term $\mu^2\Phi^{\dagger}\Phi$ is forbidden. Using the unitary gauge and the conformal scale fixing conditions we can eliminate all four real components of the Higgs field in this model. In spite of that the tree level masses of vector mesons, leptons and quarks are automatically generated and are given by the same formulas as in the conventional Standard Model. In this manner one gets the mass generation without the mechanism of spontaneous symmetry breaking. We calculated in this model the predictions for a series of electroweak observables such as $m_{W_{\pm}}/m_Z$, $sin^2\theta_W^{eff}$, Z-boson widths, $A^l_{FB}$, etc, and we show that they are in agreement with experimental data. The gravitational sector of the model is also analyzed and it is shown that the model admits in the classical limit the Einsteinian form of gravitational interactions.