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 ...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.展开更多
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)
文摘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.
