European Physical Journal C: Particles and Fields (Oct 2020)

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

  • Yin Huang,
  • Jun-Xu Lu,
  • Ju-Jun Xie,
  • Li-Sheng Geng

DOI
https://doi.org/10.1140/epjc/s10052-020-08516-4
Journal volume & issue
Vol. 80, no. 10
pp. 1 – 8

Abstract

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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.