Eur. Phys. J. C (2009) 62: 425-432
https://doi.org/10.1140/epjc/s10052-009-1017-z

Regular Article - Theoretical Physics

Magnetic moment generation from non-minimal couplings in a scenario with Lorentz-symmetry violation

¹ Departamento de Física e Química, Universidade Federal do Espírito Santo (UFES), Av. Fernando Ferrari S/N, Vitória, ES, 29060-900, Brasil
² CEFET-RJ UnED-Petrópolis, Rua do Imperador, 971, Petrópolis, RJ, 25620-003, Brasil
³ Colégio Técnico Universitário, Universidade Federal de Juiz de Fora (UFJF), Av. Bernardo Mascarenhas 1283, Juiz de Fora, MG, 36080-001, Brasil
⁴ CBPF–Centro Brasileiro de Pesquisas Físicas, Rua Xavier Sigaud 150, Rio de Janeiro, RJ, 22290-180, Brasil
⁵ International Center for Condensed Matter Physics, Universidade de Brasilia, CP 04513, Brasilia, DF, 70904-970, Brasil
⁶ Grupo de Física Teórica José Leite Lopes, CP 91933, Petrópolis, RJ, 25685-970, Brasil

^* e-mail: tcsoares@cbpf.br

Received: 30 November 2008
Revised: 12 February 2009
Published online: 5 May 2009

Abstract

This paper deals with situations that illustrate how the violation of Lorentz symmetry in the gauge sector may contribute to magnetic moment generation of massive neutral particles with spin- and spin-1. The procedure we adopt here is based on Relativistic Quantum Mechanics. We work out the non-relativistic regime that follows from the wave equation corresponding to a certain particle coupled to an external electromagnetic field and a background that accounts for the Lorentz-symmetry violation, and we thereby read off the magnetic dipole moment operator for the particle under consideration. We keep track of the parameters that govern the non-minimal electromagnetic coupling and the breaking of Lorentz symmetry in the expressions we get for the magnetic moments in the different cases we contemplate. Our claim is that the tiny magnetic dipole moment of truly-elementary neutral particles might signal Lorentz-symmetry violation.