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Taming the end-point singularities in heavy-to-light decays

Jong-Phil Lee
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Abstract

It is argued that there is a fundamental momentum cutoff in heavy-to-light transitions, which is caused by possible Cherenkov gluon radiation when an energetic light parton travels through the ''brown muck''. The soft-overlap contributions where the partonic momenta configuration is highly asymmetric are disfavored, and the problematic end-point singularities and the double countings are absent in this framework. A simple calculation with a natural scale for the cutoff gives a plausible result for the $B\toπ$ form factor.

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Jong-Phil Lee. 2007-01-30. Taming the end-point singularities in heavy-to-light decays. https://doi.org/10.1103/physrevd.75.031501

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