Electron-positron enhancement factors for an electron gas of high density within the Kahana formalism

One of the difficult problems in considering the effect of electron-positron interaction in metals is the fact that real materials differ from the electron gas. The most sophisticated theories of this interaction concern just this abstract substance. Bonderup et al. proposed that the local enhancement of the electron density on the positron in the lattice is a function of the local electron density. Therefore, there is a need for computing the enhancement parameters for a high-density electron gas. Then positron annihilation with, e.g., core electrons, is treated as annihilation with an electron gas of the corresponding density. In this work the enhancement factors were computed for the first time within the Kahana formalism for densities characterized by $0.1\le r_s<2\mathrm{}$. Based on the exact solution presented previously by Boroński et al., a successful attempt to improve self-consistency has been performed.