$B$ to light meson form factors with end-point cutoff

Abstract

Decay form factors of $B$ to light pseudoscalar ($P$) and vector ($V$) mesons are analyzed with the momentum cutoff near end point. The cutoff is caused by possible Cherenkov gluon radiation when an energetic light parton from the weak vertex travels through the ''brown muck'' of light degrees of freedom. The end-point singularities and the double countings are naturally absent. The soft-overlap contributions where the partonic momenta configuration is highly asymmetric are very suppressed in this framework. A simple calculation gives a plausible results for $B\to P,V$ form factors.