A method to measure the absolute branching fractions of decays A. Contu, D. Fonnesu, R. G. C. Oldeman, B. Saitta and C. Vacca Eur. Phys. J. C, 74 12 (2014) 3194 Published online: 04 December 2014 DOI: 10.1140/epjc/s10052-014-3194-7