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Difference in B^+ and B^0 Direct CP Asymmetry as Effect of a Fourth Generation

Wei-Shu Hou·Makiko Nagashima·Andrea Soddu
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Abstract

Direct CP violation in B^0-> K^+π^- decay has emerged at -10% level, but the asymmetry in B^+ -> K^+π^0 mode is consistent with zero. This difference points towards possible New Physics in the electroweak penguin operator. We point out that a sequential fourth generation, with sizable V^*_{t's}V_{t'b} and near maximal phase, could be a natural cause. We use the perturbative QCD factorization approach for B-> Kπamplitudes. While the B^0-> K^+π^- mode is insensitive to t', we critically compare t' effects on direct CP violation in B^+ -> K^+π^0 with b-> s\ell^+\ell^- and B_s mixing. If the K^+π^0-K^+π^- asymmetry difference persists, we predict \sin2Φ_{B_s} to be negative.

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Wei-Shu Hou, Makiko Nagashima, Andrea Soddu. 2005-08-23. Difference in B^+ and B^0 Direct CP Asymmetry as Effect of a Fourth Generation. https://doi.org/10.1103/physrevlett.95.141601

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