Time delay in two-electron photodetachment and tests of fundamental threshold laws

The photoelectron group delay, also known as the Wigner time delay (WTD), is examined in photodetachment of ${\mathrm{H}}^{\ensuremath{-}}\phantom{\rule{0.16em}{0ex}}$ and ${\mathrm{Li}}^{\ensuremath{-}}\phantom{\rule{0.16em}{0ex}}$ ions near their lowest inelastic double detachment thresholds. These threshold processes promoting remaining bound electron to an excited state or ejecting it continuum involve two active electrons are termed collectively two-electron photodetachment. opening channel governed by law which affects WTD very differently ${\mathrm{Li}}^{\ensuremath{-}}$ . At same time, Wannier behavior similar both targets. Experimental verification these theoretical predictions will subject laws a set stringent tests domain.