2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/203047The measured rate for D_s -> l nu decays, where l is a muon or tau, is larger than the standard model prediction, which relies on lattice QCD, at the 3.8 sigma level. We discuss how robust the theoretical prediction is, and we show that the discrepancy with experiment may be explained by a charged Higgs boson or a leptoquark.4 pages; v2 conforms with PRL versionHigh Energy Physics - PhenomenologyHigh Energy Physics - ExperimentHigh Energy Physics - Latticetext