The semileptonic decays of B/B_s meson in the perturbative QCD approach:a short review  

作　　者：Zhen-Jun Xiao Ying-Ying Fan Wen-Fei Wang Shan Cheng 

机构地区：[1]Department of Physics and Institute of Theoretical Physics,Nanjing Normal University [2]Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems,Nanjing Normal University [3]Institute of High Energy Physics and Theoretical Physics Center for Science Facilities,Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2014年第29期3787-3800,共14页

基　　金：supported by the National Natural Science Foundation of China (11235005 and 10975074)

摘　　要：In this short review,we present the current status about the theoretical and experimental studies for some important semileptonic decays of B=Bsmesons.We firstly gave a brief introduction for the experimental measurements for B=Bs!Peltl;l ml;m mT decays,the BaBar’s ReDT and ReD T anomaly,the P05deviation for B0!K 0ltl decay.We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule,the heavy quark effective theory,and the perturbative QCD factorization approach.By using the form factors calculated in the perturbative(pQCD)approach,we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B=Bsmesons.We also made careful phenomenological analysis for these pQCD predictions and found,in general,the following points:(a)For all the considered B=Bssemileptonic decays,the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods;(b)For ReDT and ReD T,the pQCD predictions agree very well with the data,the BaBar’s anomaly of ReDe TT are therefore explained successfully in the standard model by employing the pQCD approach;and(c)We defined several new ratios Rl;s Dand Rl;s Ds,they may be more sensitive to the QCD dynamics which controls the B=Bs!eDe T;De T sT transitions than the old ratios,we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.In this short review, we present the current status about the theoretical and experimental studies for some important semileptonic decays of B/Bs mesons. We firstly gave a brief introduction for the experimental measurements for B/Bs → P（l＋l-, l-v-l, vv-） decays, the BaBar＇s R（D） and R（D＊） anomaly, the P′5 deviation for B0→ K＊0μ＋μ decay. We then made a careful discussion about the evaluations for the relevant form factors in the light-cone QCD sum rule, the heavy quark effective theory, and the perturbative QCD factorization approach. By using the form factors calculated in the perturbative （pQCD） approach, we then calculate and show the pQCD predictions for the decay rates of many semileptonic decays of B/Bs mesons. We also made careful phenomenological analysis for these pQCD predictions and found, in general, the following points： （a） For all the considered B/Bs semileptonic decays, the next-to-leading order pQCD predictions for their decay rates agree well with the data and those from other different theoretical methods; （b） For R（D） and R（D＊）, the pQCD predictions agree very well with the data, the B aBar＇s anomaly of R （D（＊）） are therefore explained successfully in the standard model by employing the pQCD approach; and （c） We defined several new ratios RD^l,τ and RDs^l,τ, they may be more sensitive to the QCD dynamics which controls the B/Bs→（D（＊）, Ds（＊）） transitions than the old ratios, we therefore strongly suggest LHCb and the forthcoming Super-B experiments to measure these new ratios.

关 键 词：微扰QCD 衰变率 BS 介子 光锥QCD求和规则 实验测量 评论 QCD因子化 

分 类 号：O572.33[理学—粒子物理与原子核物理] O572.2[理学—物理]