In this work, we propose a $CPT$-even and Lorentz-violating dimension-five nonminimal coupling between fermionic and gauge fields, involving the $CPT$-even and Lorentz-violating gauge tensor of the Standard Model extension. This nonminimal coupling modifies the Dirac equation, whose nonrelativistic regime is governed by a Hamiltonian which induces new effects, such as an electric-Zeeman-like spectrum splitting and an anomalouslike contribution to the electron magnetic moment, among others. Some of these new effects allow one to constrain the magnitude of this nonminimal coupling in 1 part in ${10}^{16}(\mathrm{eV}{)}^{-1}$.

• Received 28 September 2012

DOI:https://doi.org/10.1103/PhysRevD.87.047701