Search for Lorentz Violation using Short-Range Tests of Gravity
  Experimental tests of the newtonian inverse square law at short range, one at Indiana University and the other at the Huazhong University of Science and Technology, have been used to set limits on Lorentz violation in the pure gravity sector of the nonminimal Standard-Model Extension. In the nonrelativistic limit, the constraints derived for the 14 independent SME coefficients for Lorentz violation acting simultaneously are of order $10^{-9}$ m$^{2}$. 
J. Long
hep-ph