Convenient location of a near-threshold proton-emitting resonance in 11B

Polish scientists working in Poland, France and USA explained the mysterious β-delayed proton decay of the neutron halo ground state of 11Be. Studies within the SMEC model suggest the existence of collective resonance, carrying many characteristics of a nearby proton-decay channel, which explains this puzzling decay. It was argued that the appearance of such near-threshold resonant states is a generic phenomenon in any open quantum system, in which bound and unbound states strongly mix.