Eur. Phys. J. C (2012) 72: 2033
https://doi.org/10.1140/epjc/s10052-012-2033-y

Regular Article - Theoretical Physics

Studying the D ^∗ K molecular structure of in the Bethe–Salpeter approach

¹ Institute of High Energy Physics, CAS, P.O. Box 918(4), Beijing, 100049, China
² Theoretical Physics Center for Science Facilities, CAS, Beijing, 100049, China
³ College of Nuclear Science and Technology, Beijing Normal University, Beijing, 100875, China
⁴ Institute of Particle Physics, Central China Normal University, Wuhan, 430079, China

^* e-mail: fenggq@ihep.ac.cn

Received: 3 May 2012
Published online: 2 June 2012

Abstract

In the heavy quark limit, we study the possible S-wave D ^∗ K molecular bound state in the Bethe–Salpeter approach in the ladder and covariant instantaneous approximations. With the kernel induced by ρ and ω exchanges, we solve the Bethe–Salpeter equation numerically and find that the bound state may exist. We assume that the observed state is an S-wave D ^∗ K molecular bound state and then calculate the decay width of the strong decay including the η–π ⁰ mixing effect. Our result for the decay width is consistent with the previous calculations and the experimental data.