Simple Model of Overlapping Feshbach Resonances

  Yaakov Yudkin  ,  Lev Khaykovich  
Bar-Ilan University

While Efimov physics is usually investigated with isolated Feshbach resonance theories many real world resonances appear in close vicinity to each other and are therefore overlapping. Here we derive a realistic model based on the mutual coupling of an open channel and two closed molecular channels while neglecting short-range physics as permitted by the narrow character of the considered resonances. It is applied to three distinct scenarios with experimental relevance. We conclude that the effect of overlapping resonances is best observed at to a truly narrow resonance in whose vicinity there is a slightly broader one. In this system the Efimov features are pushed to lower binding energies and smaller scattering lengths making their experimental observation more feasible.