2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44860The most general $SU(2)\times U(1)_Y$-symmetric quartic potential with two Higgs doublets, subject to an only softly broken discrete symmetry $(ϕ_1,ϕ_2)\to(-ϕ_1,ϕ_2)$, is considered. At tree-level, analytic bounds on the parameters are derived that ensure a stable vacuum, breaking $SU(2)\times U(1)_Y$ down to $U(1)_{em}$.from last year, but due to recent interest now on the e-print archive, 8 pages, no figures, plain latexHigh Energy Physics - Phenomenologytext