摘要
利用全息分布振幅,通过光锥求和规则在完整QCD框架内计算了D、D_s→K~*跃迁形状因子.由于只与带电流相关,D→K~*衰变只涉及4个半轻类型的跃迁形状因子A_1、A_2、A_0、V.D_s→K~*衰变既与带电流相关也与味改变中性流相关,除了上述4个跃迁形状因子外还涉及3个张量类型的跃迁形状因子T_1、T_2、T_3.整体上来看,所给出的跃迁形状因子与以前文献中通过其他方法(基于传统分布振幅的光锥求和规则、格点模拟、光前夸克模型、重轻手征夸克模型)给出的结果在误差允许的范围内基本一致.利用给出的跃迁形状因子通过半轻衰变D^+→K^(*0)l^+νl、D^0→K^(*-)l^+ν_l结合分支比的最新实验测量结果确定了CKM矩阵元︱V_(cs)︱.预言了D_s^+→K^(*0)l^+ν_l过程的分支比并和当前实验测量结果进行了比较,可以被将来更为精确的实验所检验.
By using the new holographic distribution amplitudes（DAs）for K^＊ meson,we calculate the D_（（s））→K^＊ transition form factors via the light cone sum rules（LCSR）in full QCD.Induced by the charged currents,the D→K＊transitions involve only four semileptonic form factors,i.e.A_1,A_2,A_0,V.The Ds→K＊decays can be generated by both the charged and flavor changing neutral currents and therefore involve three additional tensor form factors T_1,T_2,T_3.Generally speaking,the transition form factors given by us are compatible with corresponding results obtained via other approaches（LCSR based on the traditional DAs,Lattice,LFQM,HLχQM）in the literature.Then we extract the CKM matrix element ︱V_（cs）︱ via the experimentally well measured semileptonic decays D^＋→K^（＊0）l^＋ν_l and D^0→K^（＊-）l^＋ν_l.For the D_s→K^（＊0）l^＋ν_l decay,we predict the branching ratio with comparison to current experiments,which can be tested by more precise experiments in the future.
出处
《辽宁师范大学学报（自然科学版）》
CAS
2016年第3期332-341,共10页
Journal of Liaoning Normal University:Natural Science Edition
基金
高等学校博士学科点专项基金联合资助项目(20132136120003)
