https://doi.org/10.1140/epjc/s10052-009-0968-4
Regular Article - Theoretical Physics
B→D (*) form factors from QCD light-cone sum rules
1
Theoretische Physik 1, Fachbereich Physik, Universität Siegen, 57068, Siegen, Germany
2
Theory Division, Department of Physics, CERN, 1211, Geneva 23, Switzerland
* e-mail: khodjam@hep.physik.uni-siegen.de
Received:
6
September
2008
Revised:
5
February
2009
Published online:
18
March
2009
We derive new QCD sum rules for B→D and B→D * form factors. The underlying correlation functions are expanded near the light-cone in terms of B-meson distribution amplitudes defined in HQET, whereas the c-quark mass is kept finite. The leading-order contributions of two- and three-particle distribution amplitudes are taken into account. From the resulting light-cone sum rules we calculate all B→D (*) form factors in the region of small momentum transfer (maximal recoil). In the infinite heavy-quark mass limit the sum rules reduce to a single expression for the Isgur–Wise function. We compare our predictions with the form factors extracted from experimental B→(*) l ν l decay rates fitted to dispersive parameterizations.
© Springer-Verlag, 2009
