Asymmetry of field-induced shape resonances in hydrogen

Asymmetric resonance profiles observed in H atoms in a strong electric field are derived analytically. The most significant deviations from a Lorentzian line shape, $H^F$=γ/(${\mathrm{scre}}^2$+${\gamma }^2$), occur for resonances near the top of a potential barrier. Parametrization as a Fano profile is inappropriate. The line-shape formula, a Lorentzian with energy-dependent reduced width ${\gamma }_Q$(scre) =ln[1+Q(1-Q${)}^{\mathrm{-}1\mathrm{-}\mathrm{scre}}$]/ln[( 1-Q${)}^{\mathrm{-}1}$], depends on a single asymmetry parameter Q (0 Received 14 September 1984 DOI: https://doi.org/10.1103/PhysRevA.31.2984 ©1985 American Physical Society