Abstract

An outstanding problem in particle physics is the hierarchical pattern of fermion masses. While it is now understood the mechanism that generates these masses, it is unclear why the Yukawa couplings assume such different values, with the mass difference between the lightest and heaviest fermion that spans more than 10 orders of magnitude. Here we present a simple dynamical solution to this problem by exploring an anomaly-free twist of the Froggatt – Nielsen model. We introduce a new scalar, the so called flavon, and a set of vector-like fermions charged under an extra abelian gauge group $U(1)$. The spontaneous symmetry breaking of $U(1){FN}$ induced by the flavon generates exponentially suppressed mass eigenstates which can reproduce the fermion mass spectrum. Furthermore, the consequences of gauging such group can be explored in a rich set of both flavor conserving and flavor violating processes.

The slides of this talk can be found here