One Way to Verify the Molecular Picture of Exotic Hadrons: From DK to DDK/D(D)over-bar(*) K

Starting from 2003, a large number of the so-called exotic hadrons, such as X(3872) and D-s0*(2317), were discovered experimentally. Since then, understanding the nature of these states has been a central issue both theoretically and experimentally. As many of these states are located close to two hadron thresholds, they are believed to be molecular states or at least contain large molecular components. We argue that if they are indeed molecular states, in the way that the deuteron is a bound state of proton and neutron, then molecular states of three or more hadrons are likely, in the sense that atomic nuclei are bound states of nucleons. Following this conjecture, we study the likely existence of DDK, D (D) over barK, and D (D) over bar *K molecular states. We show that within the theoretical uncertainties of the two-body interactions deduced, they most likely exist. Furthermore, we predict their strong decays to help guide future experimental searches. In addition, we show that the same approach can indeed reproduce some of the known three-body systems from the two-body inputs, such as the deuteron-triton and the Lambda(1405)-(K) over bar N N systems.

Automated summary

Starting from 2003, the discovery of a large number of exotic hadrons triggered theoretical and experimental investigations into their nature. These exotic hadrons are believed to be molecular states with large molecular components. Experimental data and theoretical uncertainties suggest the likely existence of DDK, D (D) over barK, and D (D) over bar *K molecular states.