Lorentz violation in a uniform Newtonian gravitational field

Abstract

Lorentz invariance is one of the fundamental principles of physics, and, as such, it must be experimentally tested. The purpose of this work is to obtain, within the Standard-Model Extension, the dynamics of a Lorentzviolating spinor in a uniform Newtonian gravitational field. This is achieved by treating the spinor as a test particle and introducing the gravitational field through a uniformly accelerated observer. The nonrelativistic Hamiltonian is obtained, and some experimental consequences are discussed. One unexpected outcome of this work is that the gravitational field helps disentangle bounds on coefficients for Lorentz violation.

Testing Lorentz and CPT invariance with ultracold neutrons

“…[27], this problem can be repaired by making a spacetime-constant field redefinition ψ ¼ Wχ, where W is chosen to restore the usual time-derivative coupling. In the present case, to first order in the SME coefficients, the Hermitian operator W ¼ ð3 − γ 0 Γ 0 Þ=2 correctly works [26]. The modified Dirac equation takes the standard form i∂ 0 χ ¼ Hχ, where the Hermitian Hamiltonian reads…”

Lorentz andCPTtests with hydrogen, antihydrogen, and related systems

“…Both deuterium and antideuterium incorporate neutron coefficients for Lorentz and CPT violation and therefore a comparison of their gravitational properties would further extend tests of models such as the generalized IPM discussed in Sec. IV D. Also, deuterium and antideuterium are fermions, and as such their behavior in weak gravitational fields involves a different set of spin-dependent coefficients for Lorentz and CPT violation [9,86,96]. However, the production, trapping, and experimental manipulation of antideuterium remains at present a futuristic challenge, so detailed theoretical considerations of the free fall of antideuterium lie outside our present scope.…”

Anisotropic cubic curvature couplings

“…Analysis in the gravity sector of the SME framework beyond the linearized limit is scarce to date [28,29]. There are two aspects to this.…”