Ultra-high-energy cosmic rays and planck-suppressed lorentz invariance violation

We investigate the consequences of higher dimension Lorentz violating, CPT even kinetic operators that couple standard model fields to a non-zero vector field in an Effective Field Theory framework. Comparing the ultra-high energy cosmic ray spectrum reconstructed in the presence of such terms with data from the Pierre Auger Observatory allows us to establish stringent bounds on O(E/M-Pl)(2) suppressed violations of Lorentz invariance.