https://doi.org/10.1140/epjc/s10052-021-09422-z
Regular Article - Theoretical Physics
Studying the 
molecule in the Bethe–Salpeter equation approach
1
Junior College, Zhejiang Wanli University, 315101, Ningbo, Zhejiang, China
2
Physics Department, Ningbo University, 315211, Ningbo, Zhejiang, China
3
College of Nuclear Science and Technology, Beijing Normal University, 100875, Beijing, China
b
wangzhenyang@nbu.edu.cn
d
xhguo@bnu.edu.cn
Received:
10
May
2021
Accepted:
5
July
2021
Published online:
21
July
2021
We interpret the 
as an S-wave molecular state in the Bethe–Salpeter equation approach with the ladder and instantaneous approximations for the kernel. By solving the Bethe–Salpeter equation numerically with the kernel containing one-particle-exchange diagrams and introducing three different form factors (monopole, dipole, and exponential form factors) in the verties, we find the bound state exists. We also study the decay width of the decay to 
.
© The Author(s) 2021
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