Eur. Phys. J. C (2021) 81: 812
https://doi.org/10.1140/epjc/s10052-021-09603-w

Regular Article - Theoretical Physics

$X_1(2900)$ as a ${\overline{D}}_{1}K$ molecule

¹ Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871, Beijing, China
² Department of Engineering Physics, Tsinghua University, 100084, Beijing, China
³ College of Physics, Sichuan University, 610065, Chengdu, Sichuan, China

^b qihongrong@tsinghua.edu.cn

Received: 5 August 2021
Accepted: 28 August 2021
Published online: 14 September 2021

Abstract

The analyses of the LHCb data on X(2900) in the $D^{-}{K}^{+}$ spectrum are performed. Both dynamically generated and explicitly introduced $X_1(2900)$ are considered. The results show that both these two approaches support the interpretation of $X_1(2900)$ as a ${\overline{D}}_{1}K$ molecular state, with $J^P=1^{-}$ and an iso-singlet interpretation is much more favorable. The effect of triangle singularity on the production of $X_1(2900)$ is also discussed, and it is found that it cannot be interpreted as a pure triangle cusp.