Three-Body Recombination of Cold Atoms
Hiroya Suno, Brett D. Esry
Department of Physics, Kansas State University
Chris H. Greene
Department of Physics,JILA and University of Colorado
James P. Burke, Jr.
NIST, Gaithersburg
Three-body recombination processes are one of the main factors limiting the achievable density and lifetime of the current generation of Bose-Einstein condensates (BECs). Such processes are also important in nuclear physics and chemical dynamics.
In the present work, we shall study three-body recombination of cold helium atoms: 4He +4He +4He - 4He2 +4He. This study extends previous work1 where ultra-cold alkali atoms were treated. An extra difficulty comes from the fact that not only zero total angular momentum J = 0 states, but also J > 0 states should be taken into account because of their higher binding energy.
We will use a modified version of Smith- Whitten hyperspherical coordinates2. Using these coordinates, one can easily introduce the symmetrization effects for three identical bosons, so that the configuration space can be reduced by a factor of 3. Coupled equations in an adiabatic hyperspherical representation are then solved using the variational R-matrix method. The interaction used is a sum of helium dimer potentials from A.R. Janzen and R.A. Aziz3.
Our goal is to calculate the "event rate constant" K3 = (hbar κ/μ) σ, or the "recombination length" ρ3 = (μ K3/hbar)1/4, where σ is the cross section for three-body recombination, μ is the three-body reduced mass.
References:
1) B.D. Esry et al., Phys. Rev. Lett., 83-1751 (1999)
2) B.K. Kendrick et al., J. Chem. Phys., 110;6673 (1999)
3) A.R. Janzen and R.A. Aziz, J. Chem. Phys., 103;9626 (1995)
This work was supported by the
Chemical Sciences, Geosciences and Biosciences Division,
Office of Basic Energy Sciences,
Office of Science,
U.S. Department of Energy.
Submitted to ICPEAC 2001, July 2001 in Santa Fe, NM.
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