Electron-electron interaction in graphene at finite Fermi energy

The wave equation describing the interaction of two electrons in graphene at arbitrary value of the Fermi energy $E_F$ is derived. For the solutions of this equation, we have found the explicit forms of the density and the current which obey the continuity equation. We have traced the evolution of the wave packet during a scattering process. It is shown that the long-leaving localized quasi-stationary peak may appear at $E_F<0$ . Then this peak decays into a set of wave packets following each other. At $t\rightarrow\infty$ a total norm of all outgoing wave packets equals to that of incoming wave packet. At $E_F=0$ the localized state does not appear. For $E_F<0$ there is an infinite set of the localized solutions with the finite norms.