Resonant low-energy electron scattering on short-range impurities in   graphene
  Resonant scattering of electrons with low energies (as compared to the bandwidth) on a single neutral short-range impurity in graphene is analyzed theoretically, taking into account the valley degeneracy. Resonances dramatically increase the scattering cross-section and introduce a strong energy dependence. Analysis of the tight-binding model shows that resonant scattering is typical for generic impurities as long as they are sufficiently strong (the potential is of the order of the electron bandwidth or higher). 
D. M. Basko