Form Factor for $B\to Dl\tilde{\nu }$ in Light-Cone Sum Rules With Chiral Current Correlator

Abstract

Within the framework of QCD light-cone sum rules (LCSR), we calculate the form factor for $B\to Dl\tilde{\nu }$ transitions with chiral current correlator. The resulting form factor depends on the distribution amplitude(DA) of the $D$-meson. We try to use three kinds of DA models of the $D$-meson. In the velocity transfer region $1.14<y<1.59$, which renders the Operator Product Expansion (OPE) near light-cone $x^2=0$ go effectively, the yielding behavior of form factor is in agreement with that extracted from the data on $B\to Dl\tilde{\nu }$, within the error. In the larger recoil region $1.35<y<1.59$, the results are observed consistent with those of perturbative QCD (pQCD). The presented calculation can play a bridge role connecting those from the lattice QCD with the heavy quark symmetry and perturbative QCD(pQCD) to have an all-around understanding of $B\to Dl\tilde{\nu }$ transitions.

Comments: 13 pages, 4figures,published version in PLB