Generalized weak-binding relations of compositeness in effective field theory

Understand

We study the compositeness of near-threshold states to investigate the internal structure of exotic hadron candidates.

• Within the framework of effective field theory, Weinberg's weak-binding relation is extended to more general cases by easing several preconditions.
• First, by evaluating the contribution from the decay channel, we obtain the generalized relation for unstable quasibound states.
• Next, we generalize the relation to include the nearby CDD (Castillejo-Dalitz-Dyson) pole contribution with the help of the Pade approximant.