TESTING LORENTZ INVARIANCE WITH ATOMIC-BEAM INTERFEROMETRY

Atomic- and neutron-beam interferometry offer a sensible technique for tests of the space-time structure. One important ingredient of the space-time structure is given by the null cones, which are related to local Lorentz invariance. A possible deviation from this structure described as splitting of the null cones gives rise to non-Lorentz invariance effects. It is shown that in the nonrelativistic limit this typically amounts to a new type of spin-momentum coupling. Starting from a generalization of the Dirac equation, based on fundamental principles, reasons are given for this special kind of coupling. The outcome of this model theory is taken to propose experiments which use atomic-beam interferometry and give improved upper limits on possible non-Lorentz invariance parameters.