OpenLoops 2 Federico Buccioni, Jean-Nicolas Lang, Jonas M. Lindert, Philipp Maierhöfer, Stefano Pozzorini, Hantian Zhang and Max F. Zoller Eur. Phys. J. C, 79 10 (2019) 866 Published online: 22 October 2019 DOI: 10.1140/epjc/s10052-019-7306-2