Alberto Tonero (Trieste):

First steps toward an asymptotically safe model of electroweak interactions

Abstract:

In a minimal realization of the standard model that contains no Higgs boson the breaking of SU(2)xU(1) symmetry is provided by the coupling of gauge bosons and fermions to a nonlinear sigma model. Normally this is regarded only as an approximate description valid below some cutoff energy scale. However, if there is a UV fixed point, the higgsless theory in which the Nambu-Goldstone bosons are thought of as fundamental degrees of freedom could hold up to higher energies, becoming asymptotically safe. In this talk I will present the RG analysis of the pure bosonic model and the predictions about the contributions to the oblique S and T parameters. Moreover, I will also discuss the inclusion of fermions and the (possible) modification they introduce to the asymptotic safety picture.

download document (pdf, 873 kB)