Ho, YK.
2008.
Atomic resonances involving positrons. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 266:516-521., Number 3
AbstractThe recent theoretical studies of atomic resonances involving positrons are reviewed. The topics under discussions are the doubly-excited states of the positronium negative ion and resonance scattering in e+–H, e+–He+, Ps–H, e+–He, e+–Li, e+–Na and e+–K.
Ho, YK.
1979.
Autoionisation states of helium isoelectric sequence below the n=3 hydrogenic thresholds. Journal of Physics B: Atomic and Molecular Physics. 12:387., Number 3
AbstractThe complex rotation method is applied to calculate autoionisation states ( 1 S e , 1 P o and 3 P o ) of the helium isoelectronic sequence (Z=2-10) below the n=3 hydrogenic thresholds. The Hylleraas-type wavefunctions are employed and up to 161 terms for S states and 165 terms for P states are used, so that several lower-lying states are determined. For He and Li + states, comparisons are made with other calculations and experiments. The width of the lowest 1 P o state of helium below the n=3 threshold is determined to be (191+or-7) meV which differs quite significantly from the experimental value of (132+or-14) meV of Dhez and Ederer (1973). Furthermore, it is concluded that the width computed by the complex rotation method would not reduce to the experimental value even if more terms in the wavefunction are used.
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