Europhys. Lett.
Volume 76, Number 3, November 2006
Page(s) 388 - 394
Section The physics of elementary particles and fields
Published online 07 October 2006
Europhys. Lett., 76 (3), pp. 388-394 (2006)
DOI: 10.1209/epl/i2006-10293-3

Split two-Higgs-doublet model and neutrino condensation

F. Wang1, W. Wang1 and J. M. Yang2, 1

1  Institute of Theoretical Physics, Academia Sinica - Beijing 100080, PRC
2  CCAST(World Laboratory) - P.O. Box 8730, Beijing 100080, PRC

received 29 May 2006; accepted in final form 14 September 2006
published online 7 October 2006

We split the two-Higgs-doublet model by assuming very different vevs for the two doublets: the vev is at weak scale (174$\un{GeV}$) for the doublet $\Phi_1$ and at neutrino-mass scale ( $ 10^{-2}\mbox{--}10^{-3}\un{eV}$) for the doublet $\Phi_2$. $\Phi_1$ is responsible for giving masses to all fermions except neutrinos; while $\Phi_2$ is responsible for giving neutrino masses through its tiny vev without introducing the see-saw mechanism. Among the predicted five physical scalars H, h, A0 and $H^{\pm}$, the CP-even scalar h is as light as $ 10^{-2}\mbox{--}10^{-3}\un{eV}$ while the others are at weak scale. We identify h as the cosmic-dark-energy field and the other CP-even scalar H as the Standard Model Higgs boson; while the CP-odd A0 and the charged $H^{\pm}$ are the exotic scalars to be discovered at future colliders. Also we demonstrate a possible dynamical origin for the doublet $\Phi_2$ from neutrino condensation caused by some unknown dynamics.

12.60.Fr - Extensions of electroweak Higgs sector.
12.60.Rc - Composite models.
14.60.Pq - Neutrino mass and mixing.

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