Re-analysis of the $D^{\ast }D\pi$ coupling in the light-cone QCD sum rules

Abstract

The recent measurement from the CLEO experiment presents the $D{D}^{\ast }\pi$ coupling, $17.9\pm 0.3\pm 1.9$. This value is much larger than any of QCD sum rule predictions available in literature. We report that, with a relevant treatment of the continuum subtraction as well as with the asymptotic form of the twist-2 pion wave function, the light-cone QCD sum rule can provide the coupling comparable to the experimental value. The stability of the resulting sum rule becomes much better with these corrections.

Comments: 8 pages including 1 postscript figure