Ultracold collisions of He with highly rotationally-excited CO$_2$

POSTER

Abstract

Elastic and rotationally inelastic processes are studied for collisions of rotationally excited CO$_2$ with He. In the ultracold limit, complex scattering lengths were computed for rotational levels up to $j=200$ using the close-coupling method and the coupled-states approximation. As illustrative examples, some cross sections are also presented. This work was motivated by recent experimental efforts to generate highly excited CO$_2$ rotational states with an optical centrifuge [1] and the possibility of translationally cooling carbon dioxide with helium buffer-gas techniques. Experiments with rotationally excited and cold CO$_2$ may be feasible as the ratio of the real to imaginary components of the scattering length exceeds $\sim$30 for $j=200$. \\[4pt] [1] A. S. Mullin, L. Yuan, S. Teitelbaum, and A. Robinson, APS Bulletin, DAMOP Abstract E1.00016 (2009).

*This work was partially supported by NASA grant NNX07AP12G and NSF grant PHY-0554794.

Authors

  • W. el Qadi

    • University of Georgia

  • B.H. Yang

    • University of Georgia

  • Phillip Stancil

    • Dept. of Physics \& Astronomy, University of Georgia, Athens, GA 30602, USA
    • University of Georgia

  • Robert Forrey

    • Penn State University, Berks Campus
    • Penn State, Berks Campus
    • Pennsylvania State University
    • Penn State University

  • Balakrishnan Naduvalath

    • University of Nevada Las Vegas