### Session I4: Ultracold Scattering and Interactions

8:00 AM–10:24 AM, Thursday, May 29, 2008
Nittany Lion Inn Room: Ballroom AB

Chair: Marjatta Lyyra, Temple University

Abstract ID: BAPS.2008.DAMOP.I4.12

### Abstract: I4.00012 : Finite energy effects on dimer-dimer collisions in two-spin ultracold Fermi gases

10:12 AM–10:24 AM

Preview Abstract MathJax On | Off   Abstract

#### Authors:

Jose P. D'Incao
(JILA, Department of Physics, University of Colorado)

Seth T. Rittenhouse
(JILA, Department of Physics, University of Colorado)

Nirav P. Mehta
(JILA, Department of Physics, University of Colorado)

Chris H. Greene
(JILA, Department of Physics, University of Colorado)

We demonstrate important properties of few-body parameters which may offer deeper insight into the many-body phenomena in two-spin Fermi gases at finite temperatures. Our results indicate, for instance, that previously obtained zero energy results for the dimer-dimer scattering length can have a limited applicability to a finite temperature ultracold gas near a Feshbach resonance. In order to account for finite temperature effects we have calculated the energy dependent {\em complex} dimer-dimer scattering length, $a_{dd}(E)$, where the real and imaginary parts correspond to contributions from elastic and inelastic collisions, respectively. Our results were obtained by solving the four-body Schr\"odinger equation in the hyperspherical adiabatic representation which, despite the high complexity of the problem, offers a simple, intuitive, and quantitative picture for the collision processes. This work was supported by the National Science Foundation.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2008.DAMOP.I4.12