Subleading corrections to the V_ub determination from exclusive B decays
High Energy Physics - Phenomenology
2011-01-27 v1
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 e\nu. We estimate the leading corrections to this symmetry relation, of order \alpha_s(m_b) and \Lambda/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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Cite
@article{arxiv.hep-ph/0209211,
title = {Subleading corrections to the V_ub determination from exclusive B decays},
author = {Benjamin Grinstein and Dan Pirjol},
journal= {arXiv preprint arXiv:hep-ph/0209211},
year = {2011}
}
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8 pages