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arXiv · 2606.23523

One-loop contributions in Lorentz-violating scalar QED with nonminimal coupling

F. M. Belchior·J. R. Nascimento·A. Yu. Petrov·P. Porfirio
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Abstract

In the context of pertubative aspects of Lorentz-violating theories, we study the divergent one-loop two-point functions of a Lorentz-violating (LV) extension of scalar QED containing a dimension-five CPT-odd nonminimal coupling. The model is defined through a generalized covariant derivative involving a constant background vector and the dual electromagnetic field strength. After expanding the action, we derive the full set of vertices relevant for the photon and scalar self-energies, including the mixed minimal-nonminimal seagull interaction diagram required by the gauge invariance. Using dimensional regularization, we compute the divergent parts of the vacuum polarization and scalar self-energy. The complete photon two-point function is shown to be transverse since the mass-dependent pieces generated by the mixed and purely nonminimal bubble graphs cancel against the corresponding seagull graphs, leaving higher-derivative CPT-odd and CPT-even LV gauge counterterms. The scalar self-energy generates LV kinetic and higher-derivative counterterms. The calculation confirms that gauge invariance is preserved, while the nonminimal interaction should be understood within an effective-field-theory expansion.

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F. M. Belchior, J. R. Nascimento, A. Yu. Petrov, P. Porfirio. 2026-06-22. One-loop contributions in Lorentz-violating scalar QED with nonminimal coupling. https://doi.org/10.1140/epjp%2Fs13360-026-08187-2

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