Regular Article – Theoretical Physics
Triangle singularity as the origin of and observed in
Department of Physics, School of Science, Tianjin University, 300350, Tianjin, China
2 School of Physics, Beihang University, 100191, Beijing, China
3 College of Physics and Engineering, Qufu Normal University, 273165, Qufu, China
4 Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
5 School of Nuclear Sciences and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
6 School of Physics and Microelectronics, Zhengzhou University, 450001, Zhengzhou, Henan, China
Accepted: 13 December 2020
Published online: 22 December 2020
The LHCb collaboration recently reported the observation of a narrow peak in the invariant mass distributions from the decay. The peak is parameterized in terms of two resonances and with the quark contents , and their spin-parity quantum numbers are and , respectively. We investigate the rescattering processes which may contribute to the decays. It is shown that the rescattering via the loop and the rescattering via the loop can simulate the and with consistent quantum numbers. Such phenomena are due to the analytical property of the scattering amplitudes with the triangle singularities located to the vicinity of the physical boundary.
© The Author(s) 2020
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