2026/07/19 by Sheng-Bo Wu, Dong Huang, Fang-Ping Peng +2
#hep-ph
In this paper, we calculate the transition form factors (TFFs) A1,2(q2) and V(q2) of Ds+ → K*0 decays by using the QCD light-cone sum rule (QCD LCSR) and constructing a correlation function containing the usual current, in which the twist-2 transverse and longitudinal light-cone distribution amplitudes (LCDAs) ϕλ2;K*0(x,μ0) with λ=(\bot,‖) of the K*0 meson constitute the main source of theoretical uncertainty. Based on this, we construct these LCDAs using the light-cone harmonic oscillator model. Subsequently, the TFFs obtained in the large recoil region are A1(0)=0.579-0.028+0.024, A2(0)=0.414-0.023+0.021, and V(0)=0.830-0.020+0.020, and the corresponding ratios are obtained to be rV=1.433-0.090+0.110 and r2=0.715-0.067+0.075. Furthermore, we predict the correlation of TFFs and their corresponding ratios. Then, we extrapolate the TFFs over the whole physical q2-region and calculate the decay widths and branching fractions for the semileptonic decays Ds+→ K*0ℓ+νℓ. The results are B(Ds+→ K*0e+νe)=(2.05-0.16+0.13)× 10-3 and B(Ds+→ K*0μ+νμ)=(1.95-0.15+0.13)× 10-3. Meanwhile, we calculated the branching fraction ratio Rμ/e^K*0 to be 0.950-0.002+0.004. In addition, we extract values of the CKM matrix element, obtaining |Vcd|(e-Channel) = 0.225-0.005+0.005 and |Vcd|(μ-Channel) = 0.227-0.004+0.011. Finally, we calculated the forward-backward asymmetry parameters for the Ds+→ K*0 ℓ+νℓ decay.