In physics, Feshbach resonance, named after Herman Feshbach, is a resonance of a many-body system in which a bound state is achieved if the coupling(s) between at least one internal degree of freedom and the reaction coordinates which lead to dissociation vanish. The opposite situation, when a bound state is not formed, is a shape resonance.
Feshbach resonances have become important in the study of fermi gases, as these resonances allow for the creation of Bose–Einstein condensates (BECs). In the context of a BEC, the Feshbach resonance occurs when the energy of a bound state of an interatomic potential is equal to the kinetic energy of a colliding pair of atoms, which have hyperfine structure coupled via Coulomb or exchange interactions. This condition is rare in our local conditions, but can be satisfied in ultracold alkali atoms. Wikipedia, Feshbach Resonance
See Also
07 - Resonance Co-vibration or Sympathy of Tones
Aggregation
Assimilation
Attraction
Efimov state
Sympathetic Resonance