Resonances in positron scattering on a supercritical nucleus and spontaneous production of pairs S. I. Godunov, B. Machet and M. I. Vysotsky Eur. Phys. J. C, 77 11 (2017) 782 Published online: 20 November 2017 DOI: 10.1140/epjc/s10052-017-5325-4