The semileptonic decay within the LCSR approach under heavy quark effective field theory *

Abstract

Abstract The heavy quark effective field theory (HQEFT) provides an effective way to deal with heavy meson decays. In this paper, we adopt two different correlators to derive the light-cone sum rules (LCSR) for the transition form factors (TFFs) in the framework of HQEFT. We label the two LCSR results as LCSR- and LCSR- , which stand for the conventional correlator and the right-handed correlator. We observe that the correlation parameter for the branching ratio is , implying a consistency of LCSRs with the other correlators. Furthermore, we obtain and . We also obtain and , both of which agree with the lattice QCD predictions. Thus, HQEFT provides a useful framework for studying B meson decays. Moreover, by using the right-handed correlator, the twist-2 terms are dominant in TFF , as their contribution is over ~97% in the whole region, while the large twist-3 uncertainty of the conventional correlator is greatly suppressed. Hence, the LCSR- predictions can be used to test the properties of the various models for the pion twist-2 distribution amplitudes.