## Abstract

We calculate a number of observables related to particle-antiparticle mixing in the Littlest Higgs model with T-parity (LHT). The resulting effective Hamiltonian for ΔF = 2 transitions agrees with the one of Hubisz et al., but our phenomenological analysis goes far beyond the one of these authors. In particular, we point out that the presence of mirror fermions with new flavour and CP-violating interactions allows to remove the possible Standard Model (SM) discrepancy between the CP asymmetry S_{ψKS} and large values of |V_{ub}| and to obtain for the mass difference ΔM_{s} < (ΔM_{s})_{SM} as suggested by the recent result by the CDF collaboration. We also identify a scenario in which simultaneously significant enhancements of the CP asymmetries S_{ψφ} and A _{SL}^{q} relative to the SM are possible, while satisfying all existing constraints, in particular from the B → X_{s}γ decay and A_{CP}(B → X_{s}γ) that are presented in the LHT model here for the first time. In another scenario the second, non-SM, value for the angle γ = -(109 ± 16)° from tree level decays, although unlikely, can be made consistent with all existing data with the help of mirror fermions. We present a number of correlations between the observables in question and study the implications of our results for the mass spectrum and the weak mixing matrix of mirror fermions. In the most interesting scenarios, the latter one turns out to have a hierarchical structure that differs significantly from the CKM one.

Original language | English |
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Article number | 003 |

Journal | Journal of High Energy Physics |

Volume | 2006 |

Issue number | 12 |

DOIs | |

State | Published - 1 Dec 2006 |

## Keywords

- Beyond Standard Model
- CP violation
- Technicolor and Composite Models

## Fingerprint

Dive into the research topics of 'Particle-antiparticle mixing, ε_{K}, ΔΓ

_{q}, A

_{SL}

^{q}, A

_{CP}(B

_{d}→ ψK

_{S}), A

_{CP}(B

_{s}→ ψφ) and B → X

_{s,d}γ in the Littlest Higgs model with T-parity'. Together they form a unique fingerprint.