Theory HEP Seminar

The Conformal Standard Model

Hermann Nicolai

MPG Potsdam

One of the most striking features of the Standard Model of particle physics is its “near conformal invariance”. In this talk I will review recent work which re-examines the question of radiative symmetry breaking in the Standard Model in the presence of right-chiral neutrinos and a minimally enlarged scalar sector. It will be argued that, with these extra ingredients, the hypothesis of classically unbroken conformal symmetry, besides naturally stabilizing a hierarchy, may be compatible with all available data; in particular, there exists a set of parameters for which the model may remain viable even up to the Planck scale. The decay modes of the extra scalar field provide a unique signature of this model which can possibly be tested at LHC.