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Spin-dipole induced lifetime of the least-bound quintet sigma state of He(2S)+He(2S)

Timothy J. Beams·Gillian Peach·Ian B. Whittingham
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Abstract

The properties of the least-bound vibrational level (v=14) of the quintet sigma state formed during the ultracold collision of two spin-polarized metastable helium atoms are crucial to studies of photoassociation spectroscopy of metastable helium. We report a calculation of the autoionization lifetime of this state induced by spin-dipole coupling of the quintet sigma state to the singlet sigma state from which Penning and associative ionization processes are highly probable. We find a lifetime of about 150 microseconds, significantly larger than the recent experimental estimates of (4-5) microseconds.

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Timothy J. Beams, Gillian Peach, Ian B. Whittingham. 2006-04-24. Spin-dipole induced lifetime of the least-bound quintet sigma state of He(2S)+He(2S). https://doi.org/10.1103/physreva.74.014702

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