Branching fractions and polarizations of D→Vℓν_{ℓ} within QCD light-cone sum rule

Abstract

In this paper, we make a detailed study of the D→V helicity form factors (HFFs) within the framework of the QCD light-cone sum rule (LCSR) up to twist-4 accuracy. After extrapolating the LCSR predictions of HFFs to the whole physical q^{2} region, we get the longitudinal, transverse, and total |V_{cq}|-independent decay widths of semileptonic decay D→Vℓ^{+}ν_{ℓ}. Meanwhile, the branching fractions of these decays are also obtained by using the D^{0}(D^{+})-meson lifetime, which agrees well with the BESIII results within the error bars. As a further step, we also investigate the differential and mean predictions for charged lepton (vector meson) polarization in the final state P_{L,T}^{ℓ} (F_{L,T}^{ℓ}), the forward-backward asymmetry A_{FB}^{ℓ}, and the lepton-side convexity parameters C_{F}^{ℓ}. Our predictions are consistent with covariant confining quark model results within errors. Thus, we think the LCSR approach for HFFs is applicable for dealing with the D-meson semileptonic decays.