Derivative four-fermion model, effective action and bumblebee generation R. Araújo, T. Mariz, J. R. Nascimento and A. Yu. Petrov Eur. Phys. J. C, 84 10 (2024) 1034 Published online: 09 October 2024 DOI: 10.1140/epjc/s10052-024-13391-4