Accelerator experiments check general relativity
  The deflection of gamma-rays in Earth's gravitational field is tested in laser Compton scattering at high energy accelerators. Within a formalism connecting the bending angle to the photon's momentum it follows that detected gamma-ray spectra are inconsistent with a deflection magnitude of 2.78 nrad, predicted by Einstein's gravity theory. Moreover, preliminary results for 13-28 GeV photons from two different laboratories show opposite - away from the beam line - deflection, amounting to 33.8-0.8 prad. These conclusions, however, are applicable only for gravitationally sterile high energy electrons. Much more subtle effects are expected if the gravitational deflection of the electrons is taken into account. 
Vahagn Gharibyan
physics.gen-ph gr-qc hep-ex