中文摘要：

采用手征流关联函数改进的光锥QCD求和规则（LCSR）方法，消掉了3扭度和5扭度K介子波函数的贡献，计算了-6〈q^2〈12范围的Bs→K矢量形状因子f^bS→k-（q^2）和张量形状因子片州f^bS→k-（q^2）．进而采用z级数参数化形式拟合LCSR的结果，将其解析延拓至整个半轻子运动学区域．利用获得的形状因子形状，预言了标准模型下稀有半轻衰变Bs→k^e＋e^-（e=e,μ）的q^2分布和衰变分支比．

英文摘要：

A chiral correlator modified QCD light cone sum rule （LCSR） approach, in which the contributions can-cel out from the twist-3 and-5 wavetunctions of K meson, is empioyeo to calculate the r,Bs→K ＋ and f^bS→k-（q^2） in the region-6 〈 q^2 〈 12. Then fitted to a z-series parameterization, the resulting form factors are extrapolated analytically to the whole semileptonic region. In the framework of standard model, a prediction is made for the q^2 distributions and the decay branching ratios of Bs→k^e＋e^-（e=e,μ）.