DKmolecule in the Bethe-Salpeter equation approach in the heavy quark limit

Abstract

In the heavy quark limit, we establish the Bethe-Salpeter equation for the possible molecular state containing one heavy meson D and one light meson K. With the kernel induced by one-particle-exchange diagrams, we solve the Bethe-Salpeter equation numerically in the ladder and covariant instantaneous approximations and find that the DK bound state may exist. Assuming the observed state D*(s0)(2317)(+) is an S-wave DK molecular bound state we calculate the strong decay width of D*(s0)(2317)(+). Our prediction for the decay width Gamma(D*(s0)(2317)(+) -> D-s(+) pi(0)) is consistent with the previous investigations and the current experimental data.