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A Precision Model Independent Determination of |Vub| from B -> pi e nu

M. Christian Arnesen·Ben Grinstein·Ira Z. Rothstein·Iain W. Stewart
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Abstract

A precision method for determining |Vub| using the full range in q^2 of B-> pi \ell nu data is presented. At large q^2 the form factor is taken from unquenched lattice QCD, at q^2=0 we impose a model independent constraint obtained from B-> pi pi using the soft-collinear effective theory, and the shape is constrained using QCD dispersion relations. We find |Vub| =(3.54\pm 0.17\pm 0.44) x 10^{-3}. With 5% experimental error and 12% theory error, this is competitive with inclusive methods. Theory error is dominated by the input points, with negligible uncertainty from the dispersion relations.

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M. Christian Arnesen, Ben Grinstein, Ira Z. Rothstein, Iain W. Stewart. 2005-04-25. A Precision Model Independent Determination of |Vub| from B -> pi e nu. https://doi.org/10.1103/physrevlett.95.071802

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