Quark mixings and flavor changing interactions with singlet quarks

Abstract

Aspects of the quark mixings and flavor changing interactions are investigated in electroweak models with singlet quarks. The effects on the ordinary quark mixing are determined in terms of the quark masses and the parameters describing the mixing between the ordinary quarks q and the singlet quarks Q (q-Q mixing). Some salient features arise in the flavor changing interactions through the q-Q mixing. The unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix within the ordinary quark sector is violated, and the flavor changing neutral currents (FCNC's) appear both in the gauge and scalar couplings. The flavor changing interactions are calculated appropriately in terms of the q-Q mixing parameters and the quark masses, which really exhibit specific flavor structures. It is found that there are reasonable ranges of the model parameters to reproduce the ordinary quark mass hierarchy and the actual CKM structure even in the presence of q-Q mixing. Some phenomenological effects of the singlet quarks are also discussed. In particular, the scalar FCNC's may be more important in some cases, if the singlet quarks as well as the extra scalar particles from the singlet Higgs fields have masses $\sim$ 100 GeV -- 1 TeV.

32 pages, 7 figures, added references

References in corpus (1)

• Weak-Singlet Fermions: Models and Constraints

Cited by in corpus (12)

• Effects of mixing with quark singlets
• Probing top flavour-changing neutral scalar couplings at the CERN LHC
• Updated constraints on new physics in rare charm decays
• Signals from extra dimensions decoupled from the compactification scale
• Top flavour-changing neutral coupling signals at a linear collider
• Top and Higgs Flavor Changing Neutral Couplings in two Higgs Doublets Model
• The size of chi = arg (-Vts Vtb* Vcs* Vcb) and physics beyond the Standard Model
• Search for t->ch at e+e- Linear Colliders
• Non-unitarity of CKM matrix from the vector singlet quark mixing and neutron electric dipole moment
• Flavor-changing interactions with singlet quarks and their implications for the LHC
• Universality of strength for Yukawa couplings with extra down-type quark singlets
• Large effects on $\BsBs$ mixing by vector-like quarks