Thursday, December 20, 2012

1212.4607 (P. Ko et al.)

B -> D^(*) tau nu and B -> tau nu in chiral U(1)' models with flavored
multi Higgs doublets
   [PDF]

P. Ko, Yuji Omura, Chaehyun Yu
We discuss semileptonic and leptonic B decays, B to D^{(*)} tau nu and B to tau nu, in the chiral U(1)' models which were proposed by the present authors in the context of the top forward-backward asymmetry (A^t_FB) observed at the Tevatron. In these models, extra Higgs doublets with nonzero U(1)' charges are required in order to make the realistic mass matrix for up-type quarks. Then the extra (pseudo)scalars contribute to A^t_FB with large flavor-changing Yukawa couplings involving top quark. The contribution of the charged Higgs to A^t_FB is negligible, but it may significantly affect B decays: especially, B to D^(*) tau nu and B to tau nu. We investigate constraints on the B decays, based on the recent results in BaBar and Belle experiments, and discuss the possibility that the allowed parameter region in the B decays can achieve large A^t_ FB.
View original: http://arxiv.org/abs/1212.4607

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