Broad resonances in H− and Ps−

Abstract

Broad resonances of H− and Ps− obtained by complex-rotation methods are treated with hyperspherical calculations. The resonances are identified as a peak in the energy dependence of time delay obtained in the single-channel calculation using a hyperspherical adiabatic potential curve. The peak occurs even when the adiabatic potential is purely repulsive, because the effective potential (the sum of adiabatic potential and adiabatic correction) is attractive relative to the potential represented by its asymptotic form.