Universality of strength for Yukawa couplings with extra down-type quark singlets

Katsuichi Higuchi; Masato Senami; Katsuji Yamamoto

doi:10.1016/j.physletb.2006.06.002

paper

Universality of strength for Yukawa couplings with extra down-type quark singlets

arXiv:hep-ph/0603219 · doi:10.1016/j.physletb.2006.06.002

Abstract

We investigate the quark masses and mixings by including vector-like down-type quark singlets in universality of strength for Yukawa couplings (USY). In contrast with the standard model with USY, the sufficient $C P$ violation is obtained for the Cabibbo-Kobayashi-Maskawa matrix through the mixing between the ordinary quarks and quark singlets. The top-bottom mass hierarchy $m_{t} ≫ m_{b}$ also appears naturally in the USY scheme with the down-type quark singlets.

Only the title is shortened, accepted for Phys. Lett. B, 10 pages, 1. figure