Quark mass dependence of the X(3872) binding energy. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics Volume 726, Issue 1-3, 2013, Pages 537-543

We explore the quark-mass dependence of the pole position of the X(3872) state within the molecular picture. The calculations are performed within the framework of a nonrelativistic Faddeev-type three-body equation for the DD-π system in the JPC=1 channel. The πD interaction is parametrised via a D* pole, and a three-body force is included to render the equations well defined. Its strength is adjusted such that the X(3872) appears as a DD-* bound state 0.5 MeV below the neutral threshold. We find that the trajectory of the X(3872) depends strongly on the assumed quark-mass dependence of the short-range interactions which can be determined in future lattice QCD calculations. At the same time we are able to provide nontrivial information on the chiral extrapolation in the X channel.
Author keywords
Charmonium; Chiral dynamics; Effective field theory; Exotic hadrons