2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/206450Several scenarios beyond the minimal extension of the Standard Model still allow light non-standard Higgs bosons evading LEP bounds. We examine the mixing between a light CP-odd Higgs boson and $η_b$ states and its implications on a slight (but observable) lepton universality breaking in Upsilon decays which could be measured at the percent level at a (Super) B factory.9 pages, 7 figuresHigh Energy Physics - Phenomenologytext