Quark mixing from softly broken symmetries
High Energy Physics - Phenomenology
2009-11-10 v1
Abstract
Quark flavor mixing may originate in the soft breaking of horizontal symmetries. Those symmetries, which in the simplest case are three family U(1) groups, are obeyed only by the dimension-4 Yukawa couplings and lead, when unbroken, to the absence of mixing. Their breaking may arise from the dimension-3 mass terms of SU(2)-singlet vector-like quarks. Those gauge-singlet mass terms break the horizontal symmetries at a scale much higher than the Fermi scale, yet softly, leading to quark mixing while the quark masses remain unsuppressed.
Cite
@article{arxiv.hep-ph/0312330,
title = {Quark mixing from softly broken symmetries},
author = {W. Grimus and L. Lavoura},
journal= {arXiv preprint arXiv:hep-ph/0312330},
year = {2009}
}
Comments
9 pages, plain Latex, no figures