Supported by the National Natural Science Foundation of China(10935007,11305180);the National Program on Key Basic Research Project of China(973 Program)(2009CB825200,2015CB856700)
supported by the National Natural Science Foundation of China(10975074 and 11235005)
In this paper,we study the B→D^(*) l-l -ι semileptonic decays and calculate the branching ratios B(B→D^(*) l-l -ι) and the ratios R(D^(*)) and R_D^( l,s) by employing the perturbative QCD(pQCD)factorization appro...