Eur. Phys. J. C (2008) 55: 303-308
https://doi.org/10.1140/epjc/s10052-008-0562-1

Regular Article - Theoretical Physics

A₄ model for the quark mass matrices

¹ Centro de Física Teórica de Partículas, Instituto Superior Técnico, 1049-001, Lisboa, Portugal
² Fakultät für Physik, Universität Wien, Boltzmanngasse 5, 1090, Wien, Austria

^* e-mail: balio@cftp.ist.utl.pt
^** e-mail: helmut.kuehboeck@univie.ac.at

Received: 12 November 2007
Revised: 28 January 2008
Published online: 8 March 2008

Abstract

We propose a model for the quark masses and mixings based on an A₄ family symmetry. Three scalar SU(2) doublets form a triplet of A₄. The three left-handed-quark SU(2) doublets are also united in a triplet of A₄. The right-handed quarks are singlets of A₄. The A₄-symmetric scalar potential leads to a vacuum in which two of the three scalar SU(2) doublets have expectation values with equal moduli. Our model makes an excellent fit of the observed |V_ub/V_cb|. CP symmetry is respected in the charged gauge interactions of the quarks.