2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37100The measurements of the leptonic branching ratios BR(Ds->tau nu) and BR(Ds->mu nu) are reviewed. The values of the Ds decay constant fDs derived from the measurements are updated and a world average is calculated taking into account the large correlations between the measurements6 pages,1 figure, EPS 2001 BudapestHigh Energy Physics - Experimenttext