2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/218873We obtain the complete set of constraints on the moduli of N=4 superstring compactifications that permit "rare" marginal decays of 1/4-BPS dyons to take place. The constraints are analysed in some special cases. The analysis extends in a straightforward way to multi-particle decays. We discuss the possible relation between general multi-particle decays and multi-centred black holes.27 pagesHigh Energy Physics - Theorytext