2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44301The calculations of nuclear matrix elements of $0νββ$-decay is a challenge for nuclear physics. We are discussing here a model independent method, which could allow to test the calculations. The method is based on the factorization property of the nuclear matrix elements and requires observation of neutrinoless double $β$-decay of several nuclei.A report at the International Workshop "Neutrino Telescopes", Venice, February 22-25, 2005High Energy Physics - Phenomenologytext