We study the D-over(D, ̄) mixing and rare D decays in the littlest Higgs model. As the new weak singlet quark with the electric charge of 2/3 is introduced to cancel the quadratic divergence induced by the top quark, the standard unitary 3 × 3 Cabibbo-Kobayashi-Maskawa matrix is extended to a non-unitary 4 × 3 matrix in the quark charged currents and Z-mediated flavor changing neutral currents are generated at tree level. In this model, we show that the D-over(D, ̄) mixing parameter can be as large as the current experimental value and the decay branching ratio (BR) of D → Xu γ is small but its direct CP asymmetry could be O(10%). In addition, we find that the BRs of D → Xu ℓ+ ℓ-, D → Xu ν over(ν, ̄) and D → μ+ μ- could be enhanced to be O (10-9), O (10-8) and O (10-9), respectively.
|Number of pages||8|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2007 Oct 25|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics