Eur. Phys. J. D 65, 67-82 (2011)
https://doi.org/10.1140/epjd/e2011-20071-x

Regular Article

Atom-dimer and dimer-dimer scattering in fermionic mixtures near a narrow Feshbach resonance

¹ T.C.M. Group, University of Cambridge, Cavendish Laboratory, J. J. Thomson Ave., Cambridge CB3 0HE, UK
² Laboratoire de Physique Théorique et Modèles Statistiques, CNRS and Université Paris Sud, UMR8626, Bât. 100, 91405 Orsay, France
³ Russian Research Center Kurchatov Institute, Kurchatov Square, 123182 Moscow, Russia

^a e-mail: jfl36@cam.ac.uk

Received: 30 January 2011
Published online: 23 June 2011

Abstract

We develop a diagrammatic approach for solving few-body problems in heteronuclear fermionic mixtures near a narrow interspecies Feshbach resonance. We calculate s-, p-, and d-wave phaseshifts for the scattering of an atom by a weakly-bound dimer. The fermionic statistics of atoms and the composite nature of the dimer lead to a strong angular momentum dependence of the atom-dimer interaction, which manifests itself in a peculiar interference of the scattered s- and p-waves. This effect strengthens with the mass ratio and is remarkably pronounced in ⁴⁰K-(⁴⁰K-⁶Li) atom-dimer collisions. We calculate the scattering length for two dimers formed near a narrow interspecies resonance. Finally, we discuss the collisional relaxation of the dimers to deeply bound states and evaluate the corresponding rate constant as a function of the detuning and collision energy.