Strong decays of $${\bar{D}}^{*}K^{*}$$ D ¯ ∗ K ∗ molecules and the newly observed $$X_{0,1}$$ X 0 , 1 states

• Main Authors: Yin Huang, Jun-Xu Lu, Ju-Jun Xie, Li-Sheng Geng
• Format: Article
• Language: English
• Published: SpringerOpen 2020-10-01
• Series: European Physical Journal C: Particles and Fields
• Online Access: http://link.springer.com/article/10.1140/epjc/s10052-020-08516-4

Abstract Lately, the LHCb Collaboration reported the discovery of two new states in the $$B^+\rightarrow D^+D^- K^+$$ B + → D + D - K + decay, i.e., $$X_0(2866)$$ X 0 ( 2866 ) and $$X_1(2904)$$ X 1 ( 2904 ) . In the present work, we study whether these states can be understood as $${\bar{D}}^*K^*$$ D ¯ ∗ K ∗ molecules from the perspective of their two-body strong decays into $$D^-K^+$$ D - K + via triangle diagrams and three-body decays into $${\bar{D}}^*K\pi $$ D ¯ ∗ K π . The coupling of the two states to $${\bar{D}}^*K^*$$ D ¯ ∗ K ∗ are determined from the Weinberg compositeness condition, while the other relevant couplings are well known. The obtained strong decay width for the $$X_0(2866)$$ X 0 ( 2866 ) state, in marginal agreement with the experimental value within the uncertainty of the model, hints at a large $${\bar{D}}^*K^*$$ D ¯ ∗ K ∗ component in its wave function. On the other hand, the strong decay width for the $$X_1(2904)$$ X 1 ( 2904 ) state, much smaller than its experimental counterpart, effectively rules out its assignment as a $${\bar{D}}^*K^*$$ D ¯ ∗ K ∗ molecule.