Journal of Physics B Atomic Molecular and Optical Physics

Qualitative analysis of the right - left scattering asymmetry in low-energy collisions

E. I. Dashevskaya, E. E. Nikitin, F Perales, J. Baudon

Published Feb 14, 1997• 3 citations

Abstract

The experimental results on the right - left scattering asymmetry of helicopter-polarized atoms, either in state or colliding with Ar, are presented and qualitatively interpreted in the framework of the sudden-locking model. It is shown that this model provides a simple description of key features of the cross section difference and the relation between it and the total cross section for scattering of unpolarized atoms.

DOI: 10.1088/0953-4075/30/3/023

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Journal of Physics B Atomic Molecular and Optical Physics

Qualitative analysis of the right - left scattering asymmetry in low-energy collisions

E. I. Dashevskaya, E. E. Nikitin, F Perales, J. Baudon

Published Feb 14, 1997• 3 citations

Publisher

Abstract

DOI: 10.1088/0953-4075/30/3/023

Related papers

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Physical Review AJun 1, 19983 citations

The influence of coherence terms on the differential cross section for

\mathrm{K}(4^{2}P_{\frac{3}{2}})

interacting with Ar has been measured. The excitation with circularly polarized light directed perpendicularly to the scattering plane induces oscillations in the cross section for ${\ensuremath{\sigma}}^{+}$ light in contrast to ${\ensuremath{\sigma}}^{\ensuremath{-}}$. This asymmetry is verified by the measurement of the corresponding left-right asymmetry with respect to the scattering angle.

s

-wave amplitude for low-energy-electron scattering from the other atom. In its most accurate form, the theory requires a convolution of the electron-scattering amplitude and the initial momentum-space wave function of the Rydberg state. However, an approximate analytic solution is derived in which the

l

-mixing cross section at a particular

n

is written as the electron-scattering cross section at the mean electronic kinetic energy of the Rydberg state, multiplied by a scaling function that depends only on

n

. The analytic solution clearly exhibits the asymptotic scaling behavior of the cross sections. Collisions of

\mathrm{Na}(\mathrm{nd})+\mathrm{He}

, Ne, and Ar are treated as specific examples.

A quasiclassical analysis of the differential inelastic scattering of oriented

\mathrm{Ca}{(4s5p,}^{1}{P}_{1})

atoms on He at a collision energy of 1 eV is presented. Inelastic channels correspond to spin-changing events populating different Zeeman sublevels of three fine-structure states of

\mathrm{Ca}{(4s5p,}^{3}{P}_{j}),

j=0,

1, and 2. The magnitude of the right-left scattering asymmetry in the helicopter plane is shown to depend on the locking dynamics. The relative values of different Zeeman-specific cross sections are determined by the diffraction scattering on the attractive ${}^{1}\ensuremath{\Pi}$ state in the entrance channels, by the Coriolis mixing between degenerate components of the repulsive ${}^{3}{\ensuremath{\Sigma}}^{+}$ intermediate state, and by the radial coupling between 1-1 and ${0}^{\ensuremath{-}}{\ensuremath{-}0}^{\ensuremath{-}}$ fine-structure components of the ${}^{3}{\ensuremath{\Sigma}}^{+}{\ensuremath{-}}^{3}{\ensuremath{\Pi}}_{\ensuremath{\Omega}}$ states in the exit channels. The predicted large right-left scattering asymmetry suggests that it can be measured experimentally.