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Subleading shape functions in B -> X_u l νand the determination of |Vub|

Christian W. Bauer·Michael Luke·Thomas Mannel
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Abstract

We calculate the subleading twist contributions to the endpoint of the inclusive lepton energy spectrum in B -> X_u l ν. We show that the same two subleading twist functions that appear in the decay B -> X_s γgovern the subleading effects in this decay. Using these results we find large O(Lambda/mB) corrections to the determination of |Vub| from the endpoint of the charged lepton spectrum. Using a simple model for the relevant subleading shape functions, we estimate the uncertainty in |Vub| from Lambda/mb corrections to be at the ~ 15% level for a lower lepton energy cut of 2.2 GeV.

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Christian W. Bauer, Michael Luke, Thomas Mannel. 2002-05-15. Subleading shape functions in B -> X_u l νand the determination of |Vub|. https://doi.org/10.1016/s0370-2693(02)02444-9

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