Low-energy three-body dynamics in binary quantum gases

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Atomic, molecular, and optical physics, 2007-04, Vol.40 (7), p.1429-1441
• Main Authors: Kartavtsev, O I, Malykh, A V
• Format: Article
• Language: English
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/40/7/011

The universal three-body dynamics in ultra-cold binary Fermi and Fermi-Bose mixtures is studied. Two identical fermions of mass m and a particle of mass m1 with the zero-range two-body interaction in states of total angular momentum L = 1 are considered. Using the boundary condition model for the s-wave interaction of different particles, both eigenvalue and scattering problems are treated by solving hyper-radial equations, whose terms are derived analytically. The dependences of the three-body binding energies on the mass-ratio m/m1 for the positive two-body scattering length are calculated; it is shown that the ground and excited states arise at m/m1 > = lambda1 8.172 60 and m/m1 > = lambda2 12.917 43, respectively. For m/m1 lambda1 and m/m1 lambda2, the relevant bound states turn to narrow resonances, whose positions and widths are calculated. The 2 + 1 elastic scattering and the three-body recombination near the three-body threshold are studied, and it is shown that a two-hump structure in the mass-ratio dependences of the cross sections is connected with the rise of the bound states.