基于全息AdS/QCD分布振幅D→ρ跃迁形状因子及半轻衰变的研究

Studies on D→ρ transition form factors and semileptonic decays using holographic distribution amplitudes for theρmeson

基于新的全息AdS/QCDρ介子分布振幅,利用完整QCD光锥求和规则计算了D→ρ半轻跃迁形状因子A1、A2、A3、V,并与以前基于传统分布振幅的光锥求和规则、格点计算及最新CLEO实验给出的结果进行了比较.研究表明,所给出的跃迁形状因子整体上与CLEO实验给出的结果符合的更好.在此基础上,我们对D→ρlν半轻衰变进行了研究,计算了D+→ρ0l+ν、D0→ρ-l+ν的衰变宽度并结合分值比的最新实验测量值抽取了CKM矩阵元Vcd.利用D0→ρ-l+ν过程抽取的CKM矩阵元与当前世界平均值符合的很好,D+→ρ0l+ν对应的结果也在误差范围内与世界平均值一致.

Based on the new holographic distribution amplitudes （DAs） for ρmeson ,we calculate the D → ρform factors A1 ,A2 ,A3 ,V by using the full QCD light cone sum rules （LCSR） and compare our results with those given by LCSR based on the traditional DAs ,lattice calculation and the latest CLEO experiment .It is found that the form factors presented in this paper are more consistent with the CLEO data .Then we calculate the decay width for D0 → ρ^- l^＋ ν,D＋ → ρ^0 l^＋ νand extract the CKM matrix element Vcd by combining with the corresponding branching ratio measurements .The CKM matrix element extracted via D0 → ρ^- ^l＋ νis consistent with the current world average value （WAV） and the corresponding result for D＋ → ρ^0 l^＋ νalso compatible with WAV .