Vector-like quarks at the origin of light quark masses and mixing Francisco J. Botella, G. C. Branco, Miguel Nebot, M. N. Rebelo and J. I. Silva-Marcos Eur. Phys. J. C, 77 6 (2017) 408 Published online: 17 June 2017 DOI: 10.1140/epjc/s10052-017-4933-3