Regular Article - Theoretical Physics
Strong decays of molecules and the newly observed states
School of Physical Science and Technology, Southwest Jiaotong University, 610031, Chengdu, China
2 School of Physics and Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, 100191, Beijing, China
3 Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
4 School of Nuclear Sciences and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
5 School of Physics and Microelectronics, Zhengzhou University, 450001, Zhengzhou, Henan, China
6 Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Beihang University, 100191, Beijing, China
Accepted: 2 October 2020
Published online: 21 October 2020
Lately, the LHCb Collaboration reported the discovery of two new states in the decay, i.e., and . In the present work, we study whether these states can be understood as molecules from the perspective of their two-body strong decays into via triangle diagrams and three-body decays into . The coupling of the two states to are determined from the Weinberg compositeness condition, while the other relevant couplings are well known. The obtained strong decay width for the state, in marginal agreement with the experimental value within the uncertainty of the model, hints at a large component in its wave function. On the other hand, the strong decay width for the state, much smaller than its experimental counterpart, effectively rules out its assignment as a molecule.
© The Author(s) 2020
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