Faddeev calculation of e$^{-}$-ps scattering lengths
Abstract
The modified Faddeev equations in configuration space are applied to solve numerically the problem of the zero-energy elastic scattering of an electron by positronium at zero angular momentum. The singlet and triplet scattering lengths are calculated and zero-energy limits of elastic and ortho-para conversion cross sections are established. The results confirm and improve previous variational estimations of these parameters.