Probing Dynamical Symmetry Breaking Using Top Quark

We report our study on probing dynamical symmetry breaking physics using top quark. We assume (i)technicolor-like scenario for inducing W mass, and (ii)an effective 4-fermi interaction for inducing top mass. With these minimal assumptions, we obtain lower bound for the strength G and the upper bound for the intrinsic mass scale M of the 4-fermi interaction (ii), as we vary the interaction (i). We find that the coupling is strong, G/4π ∼ script O sign(1). From the tree-level unitarity constraint it is suggested that M should be of the order of Λ_TC ≃ 1 ∼ 2 TeV or less. We also study the consistency with the present T parameter data, and obtain another upper bound for M. Using the obtained result, we estimate the non-standard-model correction to the polarized cross section for γγ → t̄t at script O sign(G). e.g. The correction exceeds 8% at √s = 1 TeV for the case N_TC = 3.