Eur. Phys. J. C (2020) 80: 1184
https://doi.org/10.1140/epjc/s10052-020-08747-5

Regular Article – Theoretical Physics

Description of the newly observed ${\mathrm{\Xi }}_c^0$ states as molecular states

¹ College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing, People’s Republic of China
² School of Nuclear Science and Technology, Lanzhou University, 730000, Lanzhou, People’s Republic of China
³ School of Physical Science and Technology, Southwest Jiaotong University, 610031, Chengdu, People’s Republic of China

^c huangy2019@swjtu.edu.cn

Received: 8 July 2020
Accepted: 10 December 2020
Published online: 23 December 2020

Abstract

Very recently, three new structures ${\mathrm{\Xi }}_c{(2923)}^0$, ${\mathrm{\Xi }}_c{(2938)}^0$, and ${\mathrm{\Xi }}_c{(2964)}^0$ at the invariant mass spectrum of ${\mathrm{\Lambda }}_c^{+}{K}^{-}$ observed by the LHCb Collaboration trigger a hot discussion about their inner structure. In this work, we study the strong decay mode of the newly observed ${\mathrm{\Xi }}_c^0$ assuming that the ${\mathrm{\Xi }}_c^0$ is a $\overline{D}\mathrm{\Lambda }-\overline{D}\mathrm{\Sigma }$ molecular state. With the possible quantum numbers $J^p=1/2^{\pm }$ and $3/2^{\pm }$, the partial decay widths of the $\overline{D}\mathrm{\Lambda }-\overline{D}\mathrm{\Sigma }$ molecular state into the ${\mathrm{\Lambda }}_c^{+}{K}^{-}$, ${\mathrm{\Sigma }}_c^{+}{K}^{-}$,and ${\mathrm{\Xi }}_c^{+}{\pi }^{-}$ final states through hadronic loop are calculated with the help of the effective Lagrangians. By comparison with the LHCb observation, the current results of total decay width support the ${\mathrm{\Xi }}_c{(2923)}^0$ as $\overline{D}\mathrm{\Lambda }-\overline{D}\mathrm{\Sigma }$ molecule while the decay width of the ${\mathrm{\Xi }}_c{(2938)}^0$ and ${\mathrm{\Xi }}_c{(2964)}^0$ can not be well reproduced in the molecular state picture. In addition, the calculated partial decay widths with S wave $\overline{D}\mathrm{\Lambda }-\overline{D}\mathrm{\Sigma }$ molecular state picture indicate that allowed decay mode, ${\mathrm{\Xi }}_c^{+}{\pi }^{-}$, may have the biggest branching ratio for the ${\mathrm{\Xi }}_c{(2923)}^0$. The experimental measurements for this strong decay process could be a crucial test for the molecule interpretation of the ${\mathrm{\Xi }}_c{(2923)}^0$.