Scattering Cross Sections and Lorentz Violation
  To date, a significant effort has been made to adddress the Lorentz violating standard model in low-energy systems, but little is known about the ramifications for high-energy cross sections. In this talk, I discuss the modified Feynman rules that result when Lorentz violation is present and give the results of an explicit calculation for electron-positron annihilation into two photons. 
Don Colladay