We calculate the effective three-body force for bosons interacting with each other by a two-body potential tuned to a narrow zero crossing. We use the standard two-channel model parameterized by the background atom-atom interaction strength, the amplitude of the open-channel to closedchannel coupling, and the atom-dimer interaction strength. The three-body force originates from the atom-dimer interaction, but it can be dramatically enhanced for narrow crossings, i.e., for small atom-dimer conversion amplitudes.
PACS numbers:arXiv:1907.02236v1 [cond-mat.quant-gas]