Speaker
Niko Koivunen
(University of Helsinki)
Description
The models with the gauge group $SU(3)_c\times SU(3)_L\times U(1)_X$ (331-models) have
been advocated to explain why there are three fermion generations in Nature. As such they
provide partial understanding of the flavour sector. The hierarchy of fermion masses in
the Standard Model is another puzzle which remains without compelling explanation. In this
talk I present a model that incorporates Froggatt-Nielsen mechanism into a 331-model in
order to explain both fundamental problems. It turns out that no new additional scalar
representations are needed to take care of this. The 331-models thus naturally include
explanations to both the number of fermion generations and their mass hierarchy. This talk
is based on arXiv:1706.09463[hep-ph].
