Analytical investigation of the mass spectrum of tetraquarks with a relativistic approach A. Ghasempour, N. Tazimi and M. Monemzadeh Eur. Phys. J. C, 85 1 (2025) 113 Published online: 30 January 2025 DOI: 10.1140/epjc/s10052-025-13798-7