Spin–curvature interaction and dynamics of spinning particles around the Balart–Vagenas regular black hole spacetime

We investigate the dynamics of spinning test particles in the regular, electrically charged black hole spacetime recently constructed by Balart and Vagenas within Einstein’s nonlinear electrodynamics theory. For the specific case of the metric parameter α=3, the spacetime is static, spherically symmetric, asymptotically Reissner–Nordström, and possesses a regular core like Sitter like de that satisfies the weak energy condition. Employing the Mathisson-Papapetrou-Dixon equations supplemented by the Tulczyjew spin condition, we derive explicit expressions for the conserved energy and angular momentum, the effective potential, and the radial momentum for equatorial motion. The effective potential exhibits characteristic peaks whose height and location are significantly modulated by both the black hole charge Q and the particle spin s. We determine the innermost stable circular orbit (ISCO) as a function of Q and s, showing that increasing either parameter shifts the ISCO inward, albeit with opposite effects on the orbital angular momentum. The superluminal bound imposes a critical spin smax that decreases monotonically with Q, reaching approximately smax≃0.22M near the extremal charge Qext≃1.0257M. The centre-of-mass energy of head-on collisions near the event horizon grows as the particles approach the horizon and is maximised for anti-parallel spin configurations. Numerical integration of the orbit equation reveals pronounced rosette-shaped trajectories with spin-dependent precession, where larger charge confines the orbit while non-zero spin enlarges the orbital envelope. Our results demonstrate that the regular core and the nonlinear electromagnetic field imprint distinctive signatures on spinning particle dynamics, offering potential observational discriminants between regular black holes and their singular counterparts.