Efimov effect in 2n–core halo nuclei and appearance of resonant states in n–19C scattering

A brief overview of the attempts carried out by us in recent years to study the structural properties of 2n-rich halo nuclei such as 14Be, 19B, 22C, and 20C in the light of Efimov effect is presented. In particular, the effect of occurrence of Efimov state in 20C is analysed to show how it causes a resonance in n–19C scattering near scattering threshold. The observed asymmetric structure has been identified to have a close resemblance to Fano resonance widely known to occur in atomic and molecular phenomena.