摘要
We study two-body B(c)→Mc(π,K) and semileptonic Bc→Mcl^-v^-1 decays with Mc=(J/φ,Xc^0),where Xc^0=X^0(3872) is regarded as the tetraquark state ccuu(dd).With the decay constant fxc^0=(234±52) MeV determined from the data,we predict that B(B^-→Xc^0π^-) =(11.5±5.7)×10^-6,B(B^0→Xc^0K^-0)=(2.1±1.0)×10^-4,and B(Bs^0→Xc^0K^0)=(11.4±5.6)×10^-6.With the form factors in QCD models,we calculate that B(Bc^-→Xc^0π^-,Xc^0K^-)=(6.0±2.6)×10^-5 and(4.7±2.0)×10^-6,and B(Bc^-→J/φμ^-vμ^-vμ,Xc^0μ^-v^-μ)=(2.3±0.6)×10^-2 and(1.35±0.18)×10^-3,respectively,and extract the ratio of the fragmentation fractions to be fc/fu=(6.4±1.9)×10^-3.
We study two-body B(c)→Mc(π,K) and semileptonic Bc→Mcl^-v^-1 decays with Mc=(J/φ,Xc^0),where Xc^0=X^0(3872) is regarded as the tetraquark state ccuu(dd).With the decay constant fxc^0=(234±52) MeV determined from the data,we predict that B(B^-→Xc^0π^-) =(11.5±5.7)×10^-6,B(B^0→Xc^0K^-0)=(2.1±1.0)×10^-4,and B(Bs^0→Xc^0K^0)=(11.4±5.6)×10^-6.With the form factors in QCD models,we calculate that B(Bc^-→Xc^0π^-,Xc^0K^-)=(6.0±2.6)×10^-5 and(4.7±2.0)×10^-6,and B(Bc^-→J/φμ^-vμ^-vμ,Xc^0μ^-v^-μ)=(2.3±0.6)×10^-2 and(1.35±0.18)×10^-3,respectively,and extract the ratio of the fragmentation fractions to be fc/fu=(6.4±1.9)×10^-3.
基金
Supported in part by National Center for Theoretical Sciences,National Science Council(NSC-101-2112-M-007-006-MY3)
MoST(Mo ST-104-2112-M-007-003-MY3)
National Science Foundation of China(11675030)