Excited K meson, Kc(4180), with hidden charm as a D(D)over-barK bound state

Motivated by the recent discovery of two new states in the B+ -> D+D-K+ decay by the LHCb Collaboration, we study the D (D) over barK three-body system by solving the Schrodinger equation with the Gaussian Expansion Method. We show that the D (D) over barK system can bind with quantum numbers I(J(P)) = 1/2(0(-)) and a binding energy of B-3(D (D) over barK) = 48.9(-2.4)(+1.4) MeV. It can decay into J/psi K and D-s(D) over bar* via triangle diagrams, yielding a partial decay width of about 1 MeV. As a result, if discovered, it will serve as a highly nontrivial check on the nature of the many exotic hadrons discovered so far and on nonperturbative QCD as well. Assuming heavy quark spin symmetry, the same formalism is applied to study the D (D) over bar *K system, which is shown to also bind with quantum numbers I(J(P)) = 1/2(1(-)) and a binding energy of B-3(D (D) over bar *K) similar or equal to 77.3(-6.6)( +)(3.1) MeV, consistent with the results of previous works.

Automated summary

The study shows that the D(D) over barK and D(D) over bar *K systems can bind to form exotic hadrons, and can decay into different channels, providing a significant impact on verifying the properties of various exotic hadrons.