Branching fractions of B-→D-X0,1(2900) and their implications.

The exotic states X 0 , 1 (2900) with the quark flavor of c s u ¯ d ¯ are recently observed in the mass spectrum of D + K - in B - → D - D + K - by the LHCb collaboration. To explore the nature of X 0 , 1 (2900) , except for analyzing their masses and decay widths as usually did in literatures, the study of their production mechanism in B-meson weak decays would provide another important information. The amplitude of B - → D - X 0 , 1 is non-factorizable. We consider the final-state-interaction effects and calculate them via the rescattering mechanism. The measured branching fractions of B - → D - X 0 , 1 are revealed. It is manifested by B - → Λ c - Ξ c (′) 0 and Λ b 0 → P c + K - that the rescattering mechanism can result in the relatively large branching fractions. The similar processes of B - → π - X 0 , 1 are also analyzed. The isospins of X 0 , 1 can be investigated by B → D X 0 , 1 ± , 0 decays. [ABSTRACT FROM AUTHOR]