## Abstract

We propose a new method for the precise determination of |V_{td}/V_{ub}| from the ratios of branching ratios B(B→ρνν̄)/B(B→ρlν) and B(B→πνν̄)/B(B→πlν). These ratios depend only on the ratio of the Cabibbo-Kobayashi-Maskawa (CKM) elements |V_{td}/V_{ub}| with little theoretical uncertainty, when very small isospin breaking effects are neglected. As is well known, |V_{td}/V_{ub}| equals (sin γ/sin β) for the CKM version of CP violation within the standard model. We also give in detail analytical and numerical results on the differential decay width dΓ(B→K*νν̄)/dq^{2} and the ratio of the differential rates dB(B→ρνν̄)/dq^{2}/ dB(B→K*νν̄)/dq^{2} as well as B(B→ρνν̄)/B(B→K*νν̄) and B(B→πνν̄)/B(B→Kνν̄).

Original language | English |
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Article number | 013003 |

Pages (from-to) | 130031-130035 |

Number of pages | 5 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 58 |

Issue number | 1 |

Publication status | Published - 1998 Jul 1 |

## All Science Journal Classification (ASJC) codes

- Physics and Astronomy (miscellaneous)