Universality In The Atom-Exchange Reaction Involving Feshbach Molecules

We study the atom-exchange reaction involving Feshbach molecules in the overlapping Feshbach resonance at about 106.8 G in the Na-23 K-40 system. We measure the reaction-rate coefficients as a function of the magnetic field in the exothermic regime. The measured reaction-rate coefficients in the current work and the reaction-rate coefficients measured in the previous work [Phys. Rev. A 100, 032706 (2019)] in the vicinity of the overlapping Feshbach resonance at a magnetic field of about 130 G can be quantitatively explained by a universal model using the three-body parameter. Our results indicate that the universality might exist in the atom-exchange reaction involving Feshbach molecules.