Strongly interacting W's and Z's and the elastic unitarity constraint

Abstract

By employing the dictum that axiomatic principles are devoid of predictive power, we find that the the elastic unitarity constraint, applied to strong WLWL scattering, does not alter the assumed spectrum of intermediate states. In other words, if one integrates out the heavy degrees of freedom in an effective theory, then imposing elastic unitarity on the resultant low-energy theory effectively integrates back in the original heavy degrees of freedom, but otherwise leaves the spectrum unchanged. As a case study, we consider intermediate states involving a heavy Higgs and heavy fermions of a hypothetical fourth doublet. In contrast to recent studies, we find no p-wave resonance.