Two bosons in a narrowly resonant trap

Understand

It is rare for an $S$-wave resonance to remain narrow while approaching threshold as a result of the interaction parameters being fine tuned.

• Such an interaction is, however, realized by pion-charmed baryon system $\pi \Sigma_c$, which has a narrow resonance $\Lambda_c^+(2595)$ located a few MeVs above its threshold.
• We study the consequence of narrowly resonant inter-species interaction in a three-body system composed of two identical light bosons and an extremely heavy particle.
• We concern ourselves in the present paper with resonances of the three-body system, as opposed to bound states.