Ponente
Dr.
Fredy Ochoa
(Universidad Nacional de Colombia)
Descripción
In the standard model, the fermion masses are provided by Yukawa interactions consistent with the gauge symmetry and with the inclusion of only one scalar doublet. However, the mass spectrum of the quarks exhibit very different mass values, which require unnatural large tuning of the Yulawa parameters without any apparent fundamental reason. In this work we propose a new nonuniversal U(1)´ extension of the standard model with the addition of three quark singlets, two scalar singlets and one scalar doublet. By introducing additional global symmetries and mixing couplings between ordinary quarks and the new quark singlets, we obtain predictable mass relations of quarks with few free parameters. The model exhibit a natural scenary where a large hierarchical mass spectrum can be obtained by providing Yukawa couplings with a soft breaking of the global symmetry.
Autor primario
Dr.
Fredy Ochoa
(Universidad Nacional de Colombia)
Coautor
Dr.
Roberto Martinez
(Universidad Nacional de Colombia)
