In this paper we calculate the weak form factors of the decays Bc(B)→Dlν~ by using the chiral current correlator within the framework of the QCD light-cone sum rules (LCSR). The expressions of the form factors only depend on the leading twist distribution amplitude (DA) of the D meson. Three models of the D-meson distribution amplitude are employed and the calculated form factor FBc→D(0) is given. Our prediction, by using the D-meson distribution amplitude with the exponential suppression at the end points, is compatible with other approaches, and favors the three-points sum rules (3PSR) approach with the Coulumb corrections included.
@article{arxiv.hep-ph/0611113,
title = {$B_c(B){\to}D l\tilde{\nu}$ form factors in Light-Cone Sum Rules and the $D$-meson distribution amplitude},
author = {Fen Zuo and Tao Huang},
journal= {arXiv preprint arXiv:hep-ph/0611113},
year = {2008}
}