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Subleading corrections to the V_ub determination from exclusive B decays

Benjamin Grinstein·Dan Pirjol
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Abstract

It has been proposed to determine the CKM matrix element |V_ub| in a model-independent way from a combination of rare and semileptonic B and D decays near the zero recoil point. An essential ingredient in such a determination is a heavy quark symmetry relation connecting the form-factors appearing in B -> K* e+e- to semileptonic form factors relevant for B -> rho eν. We estimate the leading corrections to this symmetry relation, of order α_s(m_b) and Λ/m_b, pointing out that they can be as large as 20%, depending on the value of the matrix element of a dimension-4 operator. Dimensional analysis estimates of this matrix element give a corresponding uncertainty in |V_ub| of the order of a few percent.

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Benjamin Grinstein, Dan Pirjol. 2002-09-18. Subleading corrections to the V_ub determination from exclusive B decays. https://doi.org/10.1016/s0370-2693(02)02929-5

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