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Split two-Higgs-doublet model and neutrino condensation

Wang, F.; Wang, W.; Yang, J. M.Subjects: Physics >> The Physics of Elementary Particles and Fields

We split the two-Higgs-doublet model by assuming very different vevs for the two doublets: the vev is at weak scale (174 GeV) for the doublet Phi(1) and at neutrino-mass scale (10(-2) - 10(-3) 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, A(0) and H-+/-, the CP-even scalar h is as light as 10(-2) - 10(-3) 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 A(0) and the charged H-+/- 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. |

Subjects: Physics >> The Physics of Elementary Particles and Fields

In split supersymmetry, gauginos and Higgsinos are the only supersymmetric particles that are potentially accessible at soon-to-be-completed colliders. While direct experimental research, such as the LEP and Tevatron experiments, have given robust lower bounds on the masses of these particles, cosmic dark matter can give some upper bounds and thus have important implications for research at future colliders. In this work we scrutinize such dark matter constraints and show the allowed mass range for charginos and neutralinos (the mass eigenstates of gauginos and Higgsinos). We find that the lightest chargino must be lighter than about 1 TeV under the popular assumption M-1 = M-2/2 and about 2 or 3 TeV in other cases. The corresponding production rates of the lightest chargino at the CERN large hadron collider (LHC) and the International Linear Collider (ILC) are also given. While in some parts of the allowed region the chargino pair production rate can be larger than 1 pb at the LHC and 100 fb at the ILC, other parts of the region correspond to very small production rates, and thus there is no guarantee of finding the charginos of split supersymmetry at future colliders. |

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