Strong
Bounds on Lorentz Symmetry Violation*
The
highest energy cosmic rays observed are hadrons, with energies in excess of 1011
GeV. I show how the existence of such hadrons (with the assumption
that they got their energy through acceleration by ordinary electromagnetic
fields) very strongly constrains Lorentz symmetry violation. The difference in
maximum propagation speeds of different Standard Model particles are generally
constrained to be less than about 10-22. Non-renormalizable, CPT conserving
(dimension 6) Lorentz violating operators are constrained to arise at a scale
over an order of magnitude above the Planck scale.
*In
collabaration with O. Gagnon, McGill University.