Magnetic field dependence of ultracold inelastic collisions near a Feshbach resonance

Inelastic collision rates for ultracold Rb-85 atoms in the F = 2, m(f) = -2 state have been measured as a function of magnetic field. At 250 gauss (G), the two- and three-body loss rates were measured to be K-2 = (1.87 +/- 0.95 +/- 0.19) x 10(-14) cm(3)/s and K-3 = (4.24(-0.29)(+0.70) +/- 0.85) x 10(-25) cm(6)/s, respectively. As the magnetic field is decreased from 250 G towards a Feshbach resonance at 155 G, the inelastic rates decrease to a minimum and then increase dramatically, peaking at the Feshbach resonance. Both two- and three-body losses are important, and individual contributions have been compared with theory.