Experimental data are presented for the scattering of cold electrons by for both integral and backward scattering, down to energies of a few meV with an energy resolution of 0.95–1.5 meV (full width at half maximum) in the electron beam. The experimental data show evidence for the phenomenon of virtual-state scattering, a subject of extensive theoretical study. The measured scattering cross sections rise rapidly at low energy, to a limiting value in integral scattering in excess of 120 . In addition, analysis shows that scattering is s-wave dominated and that the s-wave scattering length is negative. All features are characteristic of virtual state scattering.
- Received 21 November 2000
- Published 9 July 2001
© 2001 The American Physical Society