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arXiv · hep-lat/9503002

Form Factors for B -> pi l nu-bar_l and B -> K* gamma Decays on the Lattice

UKQCD Collaboration·D. R. Burford·H. D. Duong·J. M. Flynn·B. J. Gough·N. M. Hazel·J. Nieves·H. P. Shanahan
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Abstract

We present a unified method for analysing form factors in B -> pi l nu-bar_l and B -> K* gamma decays. The analysis provides consistency checks on the q^2 and 1/M extrapolations necessary to obtain the physical decay rates. For the first time the q^2 dependence of the form factors is obtained at the B scale. In the B -> pi l nu-bar_l case, we show that pole fits to f^+ may not be consistent with the q^2 behaviour of f^0, leading to a possible factor of two uncertainty in the decay rate and hence in the value of |V_{ub}|^2 deduced from it. For B -> K* gamma, from the combined analysis of form factors T_1 and T_2, we find the hadronisation ratio R_{K^*} of the exclusive B -> K* gamma to the inclusive b -> s gamma rates is of order 35% or 15% for constant and pole-type behaviour of T_2 respectively.

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UKQCD Collaboration, D. R. Burford, H. D. Duong, J. M. Flynn, B. J. Gough, N. M. Hazel, J. Nieves, H. P. Shanahan. 1995-03-02. Form Factors for B -> pi l nu-bar_l and B -> K* gamma Decays on the Lattice. https://doi.org/10.1016/0550-3213(95)00223-f

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