Light-quark mass behaviour of the X(3872) as a molecular state

Chiral extrapolations of the binding energy of the X (3872) molecular state are investigated using an explicitly renormalizable framework free of finite cut-off artefacts. Insights into the binding mechanisms are discussed: if the X is less bound with the growing pion mass, its binding energy is governed by the explicit pion mass dependence from one-pion exchange; an opposite behaviour would indicate the importance of the pionmass dependent short-range interactions, in addition to pionic effects. The important role of the three-body DDπ dynamics is emphasised.