10 | | This model is an extension of the SM, where a new fourth generation of fermions, a t' and a b' with SM couplings, is added. The CKM matrix is parametrized by Vtps and Vtpb, which are supposed small, and to leading order in the expansion in Vtps and Vtpb it is given by, |

11 | | |

12 | | {{{ |

13 | | 1 0 0 0 |

14 | | 0 1-Vtps^2/2 0 Vtps |

15 | | 0 -Vtps Vtpb 1-Vtpb^2/2 Vtpb |

16 | | 0 -Vtps -Vtpb 1-Vtps^2/2 -Vtpb^2/2 |

17 | | }}} |

18 | | |

| 10 | This model is an extension of the SM, where a new fourth generation of fermions, a t' and a b' with SM couplings, is added. The CKM matrix is a generic 3x3 matrix. |