Eur. Phys. J. C (2008) 53: 607-614
https://doi.org/10.1140/epjc/s10052-007-0509-y

Regular Article - Theoretical Physics

Spontaneous CP violating phase as the CKM matrix phase

¹ Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, R.O.C.
² Institute of Theoretical Science, University of Oregon, Eugene, OR, 97403, USA

^* e-mail: hexg@phys.ntu.edu.tw

Received: 17 August 2007
Revised: 8 October 2007
Published online: 8 January 2008

Abstract

We propose that the CP violating phase in the CKM mixing matrix is identical to the CP phases responsible for the spontaneous CP violation in the Higgs potential. A multi-Higgs model with Peccei–Quinn (PQ) symmetry is constructed to realize this idea. The CP violating phase does not vanish when all Higgs masses become large. In general, here are flavor changing neutral current (FCNC) interactions mediated by neutral Higgs bosons at the tree level. However, unlike general multi-Higgs models, the FCNC Yukawa couplings are fixed in terms of the quark masses and CKM mixing angles. Implications for meson–anti-meson mixing, including recent data on D–D̄ mixing, and the electric dipole moment (EDM) of the neutron are studied. We find that the neutral Higgs boson masses can be at the order of one hundred GeV. The neutron EDM can be close to the present experimental upper bound.